TWI894701B - Transceiving method of signals and radar apparatus - Google Patents

Abstract

A transceiving method of signals and a radar apparatus are provided. The radar apparatus includes a transmitting circuit, multiple transmitting antennas, multiple receiving antennas, a receiving circuit, a selection controller and a selection circuit. The transmitting circuit is used to generate a transmission signal based on the detection signal. The receiving antenna is used to receive multiple a reflected signal. The selection controller is used to generate a control signal according to the period of the detection signal. The selection circuit is used to select one of multiple transmitting antennas to transmit the transmission signal and select one of multiple receiving antennas to receive the reflected signal to generate a radio frequency signal according to the control signal. Within one frame time, multiple combinations of transmission and reception executed according to control signals at different times correspond to multiple time-division reflected signals, and the phase differences between at least two sets of two adjacent time-division reflected signals in time sequence are equal.

Description

Signal transmitting and receiving method and radar device

The present invention relates to a signal processing technology, and in particular to a signal transceiver method and a radar device.

Radar technology has been developing for many years. Radars are primarily classified into two categories: pulse radar and continuous wave radar. Generally speaking, pulse radar transmits high-frequency pulses containing periodic information, while continuous wave radar transmits continuous wave signals. With the rapid advancement of technology, frequency modulated continuous wave (FMCW) radar has been widely used in various fields in recent years.

An FM continuous wave radar transmits a continuous wave of varying frequency during a sweep cycle. The echo produced by the wave, after reflection from an object, has a frequency difference from the transmitted signal. This frequency difference can be used to determine the distance between the object and the radar. Because FM continuous wave radar can measure the distance and speed of moving targets, it is increasingly being used in civilian applications such as road vehicle monitoring and recording systems, automotive collision avoidance radar, traffic flow sensors, and autonomous driving.

It's worth noting that FM continuous wave radar systems use array antennas to estimate the angle of reflected signals (also known as the angle of arrival (AoA)). Small changes in the distance between the radar system and an object can cause significant phase shifts at the peak of the spectrum, especially for high-frequency signals. Therefore, the phase shift corresponding to the distance difference between an object and adjacent antennas can be used to estimate the AoA.

To utilize antenna arrays, current frequency-modulated continuous wave radar systems for angle-of-arrival estimation employ a multi-receiver architecture. Multiple receiving antennas are used to receive echo signals from objects reflecting the transmitted signal.

However, traditional AoA radar architectures may encounter the following issues: the need for multiple receive paths (i.e., multiple receivers); increased power consumption; increased chip size as the number of receivers increases; and the need to calibrate the local oscillator phase at the receiver and transmitter.

The radar device embodied in the present invention includes (but is not limited to) a transmitting circuit, multiple transmitting antennas, multiple receiving antennas, a receiving circuit, a selection controller, and a selection circuit. The transmitting circuit is configured to generate a transmission signal based on a detection signal, wherein the detection signal has a periodic variation. The transmitting antenna is configured to transmit the transmission signal. The receiving antenna is configured to receive an echo signal, wherein the echo signal is generated by the transmission signal being reflected by an external object. The receiving circuit is configured to generate an internal signal based on the detection signal and a radio frequency signal. The selection controller is coupled to the transmitting circuit. The selection controller is configured to generate one or more control signals based on the period of the detection signal. The selection circuit is coupled to the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the selection controller. The selection circuit is configured to select one of the plurality of transmitting antennas to transmit a transmission signal and one of the plurality of receiving antennas to receive an echo signal to generate a radio frequency signal in response to one or more control signals generated by a selection controller. Within a frame, the plurality of transmit/receive combinations executed at different times in response to the one or more control signals correspond to a plurality of time-sharing echo signals. The phase difference between at least two sets of temporally adjacent time-sharing echo signals in these time-sharing echo signals is equal. The plurality of time-sharing echo signals include echo signals received at different times within the frame. Each transmit/receive combination comprises a combination of one of the plurality of transmitting antennas and one of the plurality of receiving antennas.

The signal transceiver method of the present embodiment includes (but is not limited to) the following steps: generating a transmission signal based on a detection signal, wherein the detection signal has a periodic variation; generating one or more control signals based on the period of the detection signal; selecting one of a plurality of transmitting antennas to transmit the transmission signal based on the one or more control signals, and selecting one of a plurality of receiving antennas to receive an echo signal to generate a radio frequency signal, wherein the echo signal is generated by the transmission signal being reflected by an external object; and generating an internal signal based on the detection signal and the radio frequency signal. Within a frame time, multiple transmit/receive combinations executed at different times in accordance with one or more control signals correspond to multiple time-sharing echo signals. The phase difference between at least two sets of temporally adjacent time-sharing echo signals in these time-sharing echo signals is equal. The multiple time-sharing echo signals include echo signals received at different times within the frame time. Each transmit/receive combination comprises a combination of one of the multiple transmitting antennas and one of the multiple receiving antennas.

The radar device embodied in the present invention includes (but is not limited to) a transmitting circuit, multiple transmitting antennas, multiple receiving antennas, a receiving circuit, a selection controller, and a selection circuit. The transmitting circuit generates a transmission signal based on a detection signal, wherein the detection signal varies periodically. The transmitting antenna transmits the transmission signal. The receiving antenna receives multiple echo signals to generate multiple radio frequency signals, wherein the echo signals are generated by reflections of the transmission signal from external objects. The receiving circuit generates an internal signal based on the detection signal and the radio frequency signal. The selection controller is coupled to the transmitting circuit. The selection controller generates a control signal based on the period of the detection signal. The selection circuit is coupled to the transmitting antenna, the receiving antenna, the transmitting circuit, the receiving circuit, and the selection controller. The selection circuit is used to select one of multiple transmitting antennas to transmit a transmission signal and one of multiple receiving antennas to receive an echo signal to generate a radio frequency signal based on a control signal generated by a selection controller. The transmitting antennas include two transmitting antennas, and the receiving antennas include two receiving antennas. The two transmitting antennas have a first distance between them, and the two receiving antennas have a second distance between them. The first distance is twice the second distance, or the second distance is twice the first distance.

To make the above features and advantages of the present invention more clearly understood, the following examples are given and described in detail with reference to the accompanying drawings.

10~40: Radar device

11: Transmitter circuit

12. TX1, TX2: Transmitting antennas

13. RX1, RX2: Receiving antennas

14: Receiving circuit

15: Select controller

16: Select circuit

161, 162: Switching circuit

171: Frequency Synthesizer

18: Modulator

19: Pulse Generator

LPF: Filter

DAC: Digital to Analog Converter

IFA: Intermediate frequency amplifier circuit

ADC: Analog to Digital Converter

TXMIX, RXMIX: Mixers

PA: amplifier

LNA: Low Noise Amplifier

IFA-1: Intermediate Frequency Amplifier

IFA-2: Correcting the Circuit

IFA-3: Filter

DO: Baseband signal

172: Pulse Generator

θ, φ: Angle of arrival

d: distance

X, Y, Z: Axes

L1~L10, B: Spacing

TRC: Transmitter and Receiver Combination

TXSC, RXSC: control signals

R: distance

O: External objects

vTX1: Virtual Transmitter Antenna

vRX1~vRX4: Virtual receiving antennas

B1~B4: Radiation field type

173: I/Q detection circuit

1310~1360: Steps

50: Computational Processor

x _{0 ,n} ( t ), x _{1 ,n} ( t ): echo signal

v _n ( m ), V _n ( k ), u _{0 ,n} ( k ), u _{1 ,n} ( k ), S _{0 ,n} ( k ), S _{1 ,n} ( k ): baseband signal

Y _{0 ,n} ( k ), Y _{1 ,n} ( k ): Evaluation signal

S1510~S1540: Steps

Figure 1 is a block diagram of components of a radar device according to one embodiment of the present invention.

Figure 2A is a block diagram of components of a radar device according to one embodiment of the present invention.

Figure 2B is a block diagram of components of a radar device according to another embodiment of the present invention.

Figure 3 is a schematic diagram of the angle of arrival according to an embodiment of the present invention.

Figure 4A is a schematic diagram of the antenna configuration according to the first embodiment of the present invention.

Figure 4B is a schematic diagram of the antenna configuration according to the second embodiment of the present invention.

Figure 5 is a schematic diagram of the detection signal cycle and antenna switching according to an embodiment of the present invention.

Figure 6A is a schematic diagram of the antenna configuration, transmission angle, and arrival angle according to an embodiment of the present invention.

Figure 6B is a schematic diagram of an antenna configuration and an equivalent virtual antenna according to an embodiment of the present invention.

Figure 6C is a schematic diagram of an antenna configuration and an equivalent virtual antenna according to another embodiment of the present invention.

Figure 7A is a schematic diagram of an antenna configuration according to the third embodiment of the present invention.

Figure 7B is a schematic diagram of the antenna configuration according to the fourth embodiment of the present invention.

Figure 8 is a schematic diagram of the antenna configuration, transmission angle, and arrival angle according to an embodiment of the present invention.

Figure 9 is a schematic diagram of the detection signal cycle and antenna switching according to an embodiment of the present invention.

Figure 10A is a schematic diagram of an antenna configuration according to the fifth embodiment of the present invention.

Figure 10B is a schematic diagram of the radiation pattern of Figure 10A.

Figure 11A is a schematic diagram of an antenna configuration according to the sixth embodiment of the present invention.

Figure 11B is a schematic diagram of the radiation pattern of Figure 11A.

Figure 12 is a block diagram of components of a radar device according to an embodiment of the present invention.

Figure 13 is a flowchart of spatial information determination according to an embodiment of the present invention.

Figure 14 is a schematic diagram of signal processing according to an embodiment of the present invention.

Figure 15 is a flow chart of a signal transceiver method according to an embodiment of the present invention.

Figure 1 is a block diagram of a radar device 10 according to an embodiment of the present invention. Referring to Figure 1 , radar device 10 includes (but is not limited to) a transmitting circuit 11, multiple transmitting antennas 12, multiple receiving antennas 13, a receiving circuit 14, a selection controller 15, and a selection circuit 16. Radar device 10 can be used in fields such as weather, speed measurement, vehicle reversing, topography, and military operations. Radar device 10 can be a Frequency Modulated Continuous Wave (FMCW) radar or an Ultra Wideband (UWB) radar.

The transmitting circuit 11 is used to generate a transmission signal based on the detection signal. The detection signal has periodic variations. In one embodiment, the frequency of the detection signal varies with time within its sweep cycle. For example, the detection signal is a periodic sawtooth wave, a triangle wave, or other carrier signal used for frequency modulation continuous wave (for example, a linear, geometric, or other chirp signal). Within the cycle, the frequency of the detection signal may gradually increase and/or gradually decrease. In another embodiment, the detection signal is a pulse signal. For example, there are peaks or valleys within a specific time interval (for example, 2, 5, or 110 nanoseconds). A pulse signal can be generated every cycle.

The transmitting antenna 12 is used to transmit a transmission signal. Specifically, the transmitted electromagnetic waves carry the transmission signal of the radar device 10. In one embodiment, because the detection signal has periodic variations, the transmitted signal also has corresponding periodic variations. In one embodiment, the transmitted signal is a spread spectrum signal with a flat frequency response across the spectrum, as opposed to a pulse signal.

In one embodiment, multiple transmitting antennas 12 form an antenna array. The number of transmitting antennas 12 in the antenna array is, for example, 2, 4, or 8, but is not limited thereto. In one embodiment, each transmitting antenna 12 may correspond to an antenna port.

The receiving antenna 13 is used to receive echo signals. In one embodiment, the radar device 100 can transmit a signal to an external object (e.g., a person, vehicle, wall, or building) via the transmitting antenna 12. The radar device 100 then receives the echo signal reflected from the external object via the receiving antenna 13. The echo signal is generated by the transmitted signal being reflected by the external object.

In one embodiment, multiple receiving antennas 13 form an antenna array. The number of receiving antennas 13 in the antenna array is, for example, 2, 4, or 8, but is not limited thereto. In one embodiment, each receiving antenna 13 corresponds to an antenna port.

The receiving circuit 14 is used to generate an internal signal based on the detection signal and the radio frequency signal. In one embodiment, the detection signal has periodic changes, and the radio frequency signal is generated based on the echo signal, which will be described in detail in subsequent embodiments.

The selection controller 15 is coupled to the transmitting circuit 11. The selection controller 15 is used to generate one or more control signals based on the cycle of the detection signal. The switching or changing time point of the control signal is, for example, at the junction of two cycles of the detection signal, and will be described in detail in subsequent embodiments.

The selection circuit 16 is coupled to the transmitting antenna 12, the receiving antenna 13, the transmitting circuit 11, the receiving circuit 14, and the selection controller 15. The selection circuit 16 is configured to select one of the transmitting antennas 12 to transmit a transmit signal and one of the receiving antennas 13 to receive the received signal to generate an RF signal based on one or more control signals generated by the selection controller 15. Each control signal corresponds to a transmit/receive combination. Each transmit/receive combination comprises a combination of one of the transmitting antennas 12 and one of the receiving antennas 13.

In other embodiments, the selection controller 15 can also be configured to generate a control signal based on the cycle of the detection signal. The selection circuit 16 can also be configured to select one of the multiple transmitting antennas 12 to transmit the transmission signal based on the control signal generated by the selection controller 15. However, no selection is made for the multiple receiving antennas 13. Instead, the multiple receiving antennas 13 are configured to synchronously receive multiple echo signals to generate multiple radio frequency signals. These echo signals are generated by reflections of the transmission signal from external objects. The receiving circuit 14 can also be configured to generate internal signals based on the detection signal and these radio frequency signals. This architecture can at least partially reduce power consumption and the size of the antenna structure or chip.

The following describes the detailed hardware architecture of the radar device 10 in more detail with reference to Figures 2A and 2B.

Figure 2A is a block diagram of components of a radar device 20 according to one embodiment of the present invention. Referring to Figure 2A , radar device 20 includes (but is not limited to) a transmitting circuit 11, a transmitting antenna 12, a receiving antenna 13, a receiving circuit 14, a selection controller 15, and a selection circuit 16. Furthermore, radar device 20 may also include (but is not limited to) a frequency synthesizer 171, a modulator 18, and a clock generator 19.

The transmit circuit 11 includes an amplifier PA and a mixer TXMIX. The amplifier PA is coupled to the mixer TXMIX. The amplifier PA amplifies a signal (e.g., the output signal of the mixer TXMIX). The mixer TXMIX mixes the signal to generate a transmission signal. Furthermore, the transmit circuit 11 may also include (but is not limited to) a filter LPF and a digital-to-analog converter DAC.

In this embodiment, the transmitting antenna 12 includes, for example, two transmitting antennas TX1 and TX2. The two transmitting antennas TX1 and TX2 form an antenna array.

In this embodiment, the receiving antenna 13 includes, for example, two receiving antennas RX1 and RX2. The two receiving antennas RX1 and RX2 form an antenna array.

The receiving circuit 14 includes a low-noise amplifier (LNA) and a mixer (RXMIX). The low-noise amplifier (LNA) is coupled to the mixer (RXMIX). The low-noise amplifier (LNA) amplifies a signal (e.g., an echo signal). The mixer (RXMIX) mixes a signal (e.g., the output signal of the low-noise amplifier (LNA)) to generate an intermediate frequency (IF) signal. Furthermore, the receiving circuit 14 may also include (but is not limited to) an intermediate frequency amplifier (IFA) and an analog-to-digital converter (ADC).

The selection circuit 16 includes switching circuits 161 and 162. The switching circuits 161 and 162 can be composed of one or more electrical components, such as multiplexers and switches, and the present invention is not limited thereto. In one embodiment, the switching circuit 161 can switch between the transmission signals received by the two transmitting antennas TX1 and TX2. In another embodiment, the switching circuit 162 can switch between the echo signals received by the two receiving antennas RX1 and RX2. In another embodiment, the selection circuit 16 can achieve selection by disabling the unused transmitting antenna of the two transmitting antennas TX1 and TX2, and disabling the unused receiving antenna of the two receiving antennas RX1 and RX2.

In this embodiment, frequency synthesizer 171 is coupled to transmit circuit 11 and receive circuit 14. In one embodiment, selection controller 15 is coupled to transmit circuit 11 via frequency synthesizer 171. In another embodiment, selection controller 15 is directly connected to transmit circuit 11. Frequency synthesizer 171 is used to generate a detection signal and provide it to transmit circuit 11, receive circuit 14, and selection controller 15. In this case, the detection signal is a continuous wave signal.

The modulator 18 can be implemented by an N-order (N is a positive integer greater than zero) oversampling modulator or an N-bit Nyquist frequency sampler.

The clock generator 19 is coupled to the frequency synthesizer 171, the modulator 18, and the analog-to-digital converter (ADC). The clock generator 19 generates a clock signal (or a local seismic fluctuation signal). The frequency synthesizer 171 generates a detection signal with a period based on the clock signal. The selection controller 15 synchronizes the detection signal based on the clock signal. Furthermore, the aforementioned synchronization of the detection signal can be considered as a situation where the duration of the control signal remaining unchanged and the period of the detection signal have a fixed overlap range. For example, the period of switching or changing the control signal can be made the same as the period of the detection signal. Alternatively, the switching or changing time point of the control signal can be synchronized with the start or end point of the detection signal period and shifted forward or backward by a predetermined time. Alternatively, the switching or changing time point of the control signal can be synchronized with the start or end point of the detection signal period.

In one embodiment, modulator 18 oversamples and modulates the clock signal to generate a sine-wave-like digital signal, which then drives the digital-to-analog converter (DAC) to generate an analog sine wave signal. The analog sine wave signal is then low-pass filtered by the LPF filter to form a sine wave signal that is input to mixer TXMIX. Mixer TXMIX mixes (e.g., up-converts) the sine wave signal based on a detection signal (e.g., a continuous wave signal) from frequency synthesizer 171 to form a transmission signal. The transmission signal is then transmitted via the transmitting antenna TX1 or TX2, whichever is switched on/off by switching circuit 161.

Meanwhile, the echo signal is received by the receiving antenna RX1 or RX2, which is switched on/off by the switching circuit 162. The low-noise amplifier LNA amplifies the echo signal received by the receiving antenna RX1 or RX2, and the mixer RXMIX mixes (e.g., down-converts) the amplified signal with the detection signal (e.g., a continuous wave signal) generated by the frequency synthesizer 171 to generate an intermediate frequency signal.

The intermediate frequency amplifier circuit (IFA) includes an intermediate frequency amplifier (IFA-1), an optional correction circuit (IFA-2), and a filter (IFA-3). The intermediate frequency amplifier (IFA-1) filters the intermediate frequency signal and amplifies the signal in a specific frequency band. The filter then filters the signal in the desired frequency band and converts it into a baseband signal (DO) (e.g., a baseband digital signal) via an analog-to-digital converter (ADC). The correction circuit (IFA-2) can be a summing circuit and can sum the intermediate frequency signal with an inverted sine wave signal (i.e., the analog sine wave signal generated by the digital-to-analog converter (DAC) is subtracted from the intermediate frequency signal). Correction circuit IFA-2 can correct for issues such as flicker noise, DC offset, and local oscillator leakage encountered by the echo signal based on the sine wave signal. In other embodiments, the location of correction circuit IFA-2 may be different. For example, it may be located before intermediate frequency amplifier IFA-1 (i.e., coupled between mixer RXMIX and intermediate frequency amplifier IFA-1) or after filter IFA-3 (i.e., coupled between filter IFA-3 and analog-to-digital converter ADC).

Figure 2B is a block diagram of components of a radar device 30 according to another embodiment of the present invention. Referring to Figure 2B , radar device 30 includes (but is not limited to) a transmitting circuit 11, a transmitting antenna 12, a receiving antenna 13, a receiving circuit 14, a selection controller 15, and a selection circuit 16. Furthermore, radar device 30 may also include (but is not limited to) a pulse generator 172, a modulator 18, and a clock generator 19. The transmitting circuit 11 of Figure 2B may also include (but is not limited to) an LPF filter and a digital-to-analog converter (DAC). The receiving circuit 14 of Figure 2B may also include (but is not limited to) an intermediate frequency amplifier (IFA) and an analog-to-digital converter (ADC).

The description of the transmitting circuit 11, transmitting antenna 12, receiving antenna 13, receiving circuit 14, selection controller 15, selection circuit 16, modulator 18, clock generator 19, LPF filter, digital-to-analog converter DAC, intermediate frequency amplifier circuit IFA, and analog-to-digital converter ADC in Figure 2B can be found in the descriptions of the same symbols in Figures 1 and 2A and will not be repeated here.

In this embodiment, a pulse generator 172 is coupled to the transmit circuit 11 and the receive circuit 14. The pulse generator 172 generates a detection signal and provides it to the transmit circuit 11, the receive circuit 14, and the selection controller 15. In this embodiment, the detection signal is a pulse signal. In one embodiment, the selection controller 15 is coupled to the transmit circuit 11 via the pulse generator 172. In another embodiment, the selection controller 15 is directly connected to the transmit circuit 11, and the transmit circuit 11 can generate a pulse signal by turning on and off the signal output. In this embodiment, the clock generator 19 is coupled to the pulse generator 172, the modulator 18, and the analog-to-digital converter (ADC). The clock generator 19 generates a clock signal (or a local seismic signal). The pulse generator 172 generates a periodic detection signal based on the clock signal. The selection controller 15 synchronizes the detection signal with the clock signal. Furthermore, the aforementioned synchronization of the detection signal can be considered as ensuring that the duration of the control signal remains constant and the period of the detection signal have a fixed overlap range. For example, the period of switching or changing the control signal can be made identical to the period of the detection signal. Alternatively, the switching or changing time of the control signal can be synchronized with the start or end of the detection signal period and shifted forward or backward by a predetermined time. Alternatively, the switching or changing time of the control signal can be synchronized with the start or end of the detection signal period.

FIG3 is a schematic diagram of the angle of arrival θ according to one embodiment of the present invention. Referring to FIG3 , radar devices 20 and 30 can transmit signals to an external object (also referred to as a target) via transmitting antenna TX1. Receiving antennas RX1 and RX2 receive echo signals reflected from the external object. Assume that on the X-Y plane, the two receiving antennas RX1 and RX2 are separated by a distance d (e.g., half the wavelength of the detection signal), with receiving antenna RX2 being farther from transmitting antenna TX1 than receiving antenna RX1. Therefore, the round-trip distance from transmitting antenna TX1, through the external object, to receiving antenna RX1 differs from the round-trip distance from transmitting antenna TX1, through the external object, to receiving antenna RX2 by dsinθ. The distance difference dsin θ will be reflected in the phase difference between the echo signals from the two receiving antennas RX1 and RX2, and the arrival angle θ can be estimated based on this.

For example, transmitting antenna TX1 transmits a continuous wave signal of one frame (corresponding to one or more cycles). By performing a two-dimensional Fast Fourier Transform (FFT) on the baseband signals corresponding to the two receiving antennas RX1 and RX2, two peaks are obtained at the same distance (corresponding to the location of the external object) but with different phases. The phase difference ( ω ) between these two peaks can then be used to estimate the angle of arrival θ of the external object:

λ is the wavelength, and d is the distance between the two receiving antennas RX1 and RX2.

FIG4A is a schematic diagram of an antenna configuration according to a first embodiment of the present invention. Referring to FIG4A , a plurality of transmitting antennas 12 include two transmitting antennas TX1 and TX2 located in the X-Y/Y-X plane. A distance L1 is defined between the two transmitting antennas TX1 and TX2 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto). A plurality of receiving antennas 13 include two receiving antennas RX1 and RX2 located in the X-Y/Y-X plane. A distance L2 is defined between the two receiving antennas RX1 and RX2 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto). The transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are arranged along an X-axis parallel to the X-Y plane or along a Y-axis parallel to the Y-X plane. That is, the transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are arranged in the same direction. Transmitting antenna TX1 is closer to receiving antennas RX1 and RX2 than transmitting antenna TX2; and receiving antenna RX1 is closer to transmitting antennas TX1 and TX2 than receiving antenna RX2. There is a distance B between transmitting antenna TX1 and receiving antenna RX2 (which can be defined according to the designer's requirements). Along the Y-axis parallel to the X-Y plane or along the X-axis parallel to the Y-X plane, the distance between transmitting antennas TX1/TX2 and receiving antennas RX1/RX2 is zero (i.e., they are arranged along an imaginary straight line parallel to the X-axis or along the Y-X plane).

In one embodiment, distance L1 is equal to or the same as distance L2. In another embodiment, distance L1 is twice the distance L2. In yet another embodiment, distance L2 is twice the distance L1. In other embodiments, distance L1 and distance L2 may be in other ratios.

It should be noted that the X-Y/Y-X plane is formed by the X-axis (corresponding to the horizontal direction in the X-Y plane and the vertical direction in the Y-X plane) and the Y-axis (corresponding to the vertical direction in the X-Y plane and the horizontal direction in the Y-X plane), with the X-axis being perpendicular to the Y-axis.

Figure 4B is a schematic diagram of an antenna configuration according to a second embodiment of the present invention. Referring to Figure 4B , the antenna configuration differs from the first embodiment of Figure 4A in that a distance (defined by the designer) is provided between the transmitting antennas TX1/TX2 and the receiving antennas RX1/RX2 along the Y-axis parallel to the X-Y plane or along the X-axis parallel to the Y-X plane. As shown in the figure, antennas RX1/RX2 are further away from the transmitting antennas TX1/TX2 along the X-axis parallel to the X-Y plane or the Y-axis parallel to the Y-X plane.

In one embodiment, a frame time includes multiple transmit/receive cycles, which correspond to the period of the detection signal. For example, Figure 5 is a schematic diagram of the periods of detection signals TS1 and TS2 and antenna switching according to one embodiment of the present invention. Referring to Figure 5 , the detection signal is, for example, a continuous wave signal, expressed as a chirp signal (frequency varying over time). In this embodiment, the period of the detection signal is, for example, a period of frequency variation of the detection signal. In the exemplary detection signal TS1, the frequency variation is expressed as a triangular wave. Within a cycle of a triangular wave, its frequency increases/rises over time during the rising phase and decreases/decreases over time during the falling phase. Alternatively, in another example, the detection signal TS2 exhibits a sawtooth wave with varying frequency. Within a cycle of a sawtooth wave, its frequency increases/rises over time during the rising phase and drops directly to a trough during the falling phase. One frame time consists of three transmit/receive cycles. Each transmit/receive cycle may, for example, include two cycles of the detection signal TS1 or four cycles of the detection signal TS2.

The switching circuits 161 and 162 of the selection circuit 16 are used to select only one of the multiple transmitting antennas 12 (in this embodiment, transmitting antennas TX1 and TX2) to transmit a transmission signal in each transmit/receive cycle during a frame time according to one or more control signals, and to select only one of the multiple receiving antennas 13 (in this embodiment, receiving antennas RX1 and RX2) to receive an echo signal in each transmit/receive cycle during a frame time. That is, during a transmit/receive cycle, the switching circuit 161 of the selection circuit 16 only turns on/selects one transmitting antenna 12 (i.e., selects TX1 or TX2), thereby interrupting the signals transmitted by the transmitting circuit 11 to the other transmitting antennas. Furthermore, the switching circuit 162 of the selection circuit 16 only turns on/selects/uses one receiving antenna 13 (i.e., selects RX1 or RX2), thereby interrupting the signals transmitted by the other receiving antennas to the receiving circuit 14. During this transmit/receive cycle, the transmitting antenna 12 (TX1 or TX2) and the receiving antenna 13 (RX1 or RX2) that are turned on/selected/used form a transmit/receive combination.

Taking FIG5 as an example, the control signal TXSC for transmitting antennas TX1 and TX2 is coded "1" to indicate that only transmitting antenna TX1 is turned on/selected/used (transmitting signals are transmitted only via transmitting antenna TX1 and signals transmitted to transmitting antenna TX2 by transmitting circuit 11 are interrupted), and coded "2" to indicate that only transmitting antenna TX2 is turned on/selected/used (transmitting signals are transmitted only via transmitting antenna TX2 and signals transmitted to transmitting antenna TX1 by transmitting circuit 11 are interrupted). On the other hand, the control signal RXSC for receiving antennas RX1 and RX2 is coded "1" to enable/select/use only receiving antenna RX1 (receiving only the echo signal from receiving antenna RX1 by receiving circuit 14 and interrupting the signal from receiving antenna RX2 to receiving circuit 14). A code of "2" indicates enabling/selecting/use only receiving antenna RX2 (receiving only the echo signal from receiving antenna RX2 by receiving circuit 14 and interrupting the signal from receiving antenna RX1 to receiving circuit 14). In this embodiment, the control signal TXSC can be considered to control the selection of transmitting antenna TX1 or TX2, and the control signal RXSC can be considered to control the selection of receiving antenna RX1 or RX2. However, in other embodiments, the same control signal can control both the selection of transmitting antenna TX1 or TX2 and the selection of receiving antenna RX1 or RX2.

"TX1+RX1" represents the TRC combination of transmitting antenna TX1 and receiving antenna RX1; "TX1+RX2" represents the TRC combination of transmitting antenna TX1 and receiving antenna RX2; "TX2+RX1" represents the TRC combination of transmitting antenna TX2 and receiving antenna RX1; and "TX2+RX2" represents the TRC combination of transmitting antenna TX2 and receiving antenna RX2.

Furthermore, the duration of the signal corresponding to any code (e.g., "1" or "2") of the control signals TXSC and RXSC corresponds to the period of the detection signal. For example, the two codes correspond to a triangular wave detection signal TS1 or a sawtooth wave detection signal TS2. The switching timing between two adjacent codes of the control signals TXSC and RXSC can be, for example, at the start, end, or end of the period of the detection signals TS1 and TS2. Alternatively, the switching timing between two adjacent codes of the control signals TXSC and RXSC can be shifted forward or backward by a predetermined time from the start, end, or end of the period of the detection signals TS1 and TS2. As shown in Figure 2A or Figure 2B, the control signal is generated based on the detection signal from the frequency synthesizer 171 or the pulse generator 172, and the detection signal is generated based on the clock signal provided by the clock generator 19. Therefore, the switching timing and cycle of the control signal can be synchronized with the clock signal.

In one embodiment, in the first operating mode, a frame time includes three transceiver cycles. These three transceiver cycles include a first transceiver cycle, a second transceiver cycle, and a third transceiver cycle. These transceiver cycles correspond to multiple transceiver combination TRCs, with one transceiver cycle corresponding to one transceiver combination TRC. Switching circuits 161 and 162 of selection circuit 16 select transmitting antenna TX1 and receiving antenna RX1 (corresponding to the transmit/receive pairing combination TRC of "TX1 + RX1") in the first transmit/receive cycle, select transmitting antenna TX1 and receiving antenna RX2 or transmitting antenna TX2 and receiving antenna RX1 (corresponding to the transmit/receive pairing combination TRC of "TX1 + RX2" or "TX2 + RX1") in the second transmit/receive cycle, and select transmitting antenna TX2 and receiving antenna RX2 (corresponding to the transmit/receive pairing combination TRC of "TX2 + RX2") in the third transmit/receive cycle based on one or more control signals TXSC and RXSC. In other embodiments, the operations of the three transmit/receive cycles may be reversed in timing based on component configuration, signal transmission, or data computation requirements.

In this way, transmitting antennas TX1 and TX2 alternately transmit signals in a time-sharing manner, while receiving antennas RX1 and RX2 alternately receive echo signals in a time-sharing manner, achieving an effect similar to that of a single transmitting antenna and three receiving antennas. Each transmission and reception period only passes through a single receiver path, reducing current consumption and the need for localized seismic phase correction. The symmetrical architecture of dual transmitting and dual receiving antennas also reduces the size of the transceiver module, making the overall system module more compact. Furthermore, the architecture of this embodiment can obtain spatial information about more external objects, meaning it can more accurately determine their spatial information. For example, this embodiment can distinguish more external objects that are at the same distance from the receiving antennas at the same time.

In another embodiment, each transmit/receive cycle can be half a cycle of the detection signal TS1 (i.e., corresponding to a rising or falling segment of a triangular wave) or a full cycle of the detection signal TS2 (i.e., corresponding to a sawtooth wave). Taking Figure 5 as an example, the control signals TXSC and RXSC at the bottom switch to a different transmit/receive combination for each cycle of the detection signal TS2. A frame period consists of four transmit/receive cycles. For example, the first, second, third, and fourth transmit/receive cycles are sequentially arranged. Switching circuits 161 and 162 of selection circuit 16 select, based on one or more control signals, transmitting antenna TX1 and receiving antenna RX1 during a first transceiver cycle (corresponding to a transceiver pairing combination TRC of "TX1 + RX1"); selecting transmitting antenna TX1 and receiving antenna RX2 during a second transceiver cycle (corresponding to a transceiver pairing combination TRC of "TX1 + RX2"); selecting transmitting antenna TX2 and receiving antenna RX1 during a third transceiver cycle (corresponding to a transceiver pairing combination TRC of "TX2 + RX1"); and selecting transmitting antenna TX2 and receiving antenna RX2 during a fourth transceiver cycle (corresponding to a transceiver pairing combination TRC of "TX2 + RX2").

However, the transmission and reception period and the detection signal period may also be in other proportions.

In one embodiment, within a frame time, multiple transmit/receive combinations executed at different times (e.g., different transmit/receive cycles) in accordance with one or more control signals correspond to multiple time-sharing echo signals. "Time-sharing" means that the receiving antennas RX1 and RX2 take turns receiving the echo signal at different times. The time-sharing echo signal includes the echo signals received at different times (e.g., different transmit/receive cycles) within the frame time. Taking Figure 5 as an example, a frame time includes four transmit/receive cycles (corresponding to the control signals TXSC and RXSC at the bottom), and the echo signal received during any transmit/receive cycle is called a time-sharing echo signal.

In one embodiment, the phase difference between at least two sets of temporally adjacent time-sharing echo signals among these time-sharing echo signals is equal. Specifically, Figure 6A is a schematic diagram illustrating the antenna configuration, transmission angle, and arrival angle according to one embodiment of the present invention. Referring to Figures 4A and 6A, transmitting antennas TX1 and TX2, and receiving antennas RX1 and RX2 are arranged in a row spatially along the same direction (e.g., horizontally in the drawing). The distance L1 in Figure 4A is equal to the distance 2d in Figure 6A, and the distance L2 in Figure 4A is equal to the distance d in Figure 6A. In other words, the distance L1 is twice the distance L2. Therefore, the distances from transmitting antenna TX1 and transmitting antenna TX2 to (external) object O differ by 2dsin θ, and the distances from object O to receiving antenna RX1 and receiving antenna RX2 differ by dsin θ. The arrival angle θ is the angle of object O relative to radar devices 10, 20, and 30 degrees.

Two transmitting antennas TX1 and TX2 and two receiving antennas RX1 and RX2 can form four different transmit/receive combinations. Each transmit/receive combination consists of one of the two transmitting antennas TX1 and TX2 combined with one of the two receiving antennas RX1 and RX2. For example, Figure 5 shows "TX1 + RX1," "TX1 + RX2," "TX2 + RX1," and "TX2 + RX2."

The time-sharing echo signals received during different transmit and receive cycles vary in distance, as shown in Figure 6A . This distance difference can form a virtual antenna configuration. Figure 6B is a schematic diagram of an antenna configuration and an equivalent virtual antenna according to an embodiment of the present invention. Referring to FIG. 6B , if the distance L1 between the two transmitting antennas TX1 and TX2 (e.g., distance 2d) is twice the distance L2 between the two receiving antennas RX1 and RX2 (e.g., distance d), or the distance L2 between the two receiving antennas RX1 and RX2 (e.g., distance 2d) is twice the distance L1 between the two transmitting antennas TX1 and TX2 (e.g., distance d), then these transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are equivalent to virtual antennas arranged in the same direction (e.g., horizontal direction of the figure). A virtual transmitting antenna vTX1, a virtual receiving antenna vRX1, a virtual receiving antenna vRX2, a virtual receiving antenna vRX3, and a virtual receiving antenna vRX4 are provided. There is a first virtual distance (e.g., distance d) between the virtual receiving antennas vRX1 and vRX2, a second virtual distance (e.g., distance d) between the virtual receiving antennas vRX2 and vRX3, and a third virtual distance (e.g., distance d) between the third virtual receiving antenna and the virtual receiving antenna vRX4. Furthermore, the first virtual distance, the second virtual distance, and the third virtual distance are equal. For example, the distance is d. d can be half the wavelength of the detection signal, but is not limited to this.

Therefore, at the first time (e.g., the first transmit/receive cycle), the time-sharing echo signal from the virtual transmitting antenna vTX1 to the virtual receiving antenna vRX1 will have a phase difference in distance. At the second time (e.g., the second transmit/receive cycle), the propagation distance of the time-sharing echo signal from the virtual transmitting antenna vTX1 to the virtual receiving antenna vRX2 is one distance dsin θ greater than the propagation distance of the time-sharing echo signal at the first time. The phase difference between the above two time-sharing echo signals is Similarly, at the third time (e.g., the third transmit/receive cycle), the transmission distance of the time-sharing echo signal from the virtual transmitting antenna vTX1 to the virtual receiving antenna vRX3 is one distance dsin θ greater than the transmission distance of the time-sharing echo signal at the second time; at the fourth time (e.g., the fourth transmit/receive cycle), the transmission distance of the time-sharing echo signal from the virtual transmitting antenna vTX1 to the virtual receiving antenna vRX4 is one distance dsin θ greater than the transmission distance of the time-sharing echo signal at the third time. Therefore, the phase difference between two adjacent time-sharing echo signals among the four time-sharing echo signals received in four time periods (e.g., four transmit/receive cycles) is The phase difference between these adjacent time-division echo signals can be defined as a vector a(θ) of a uniform linear array (ULA):

In addition, when the distance L1 (e.g., 2d) between the two transmitting antennas TX1 and TX2 is twice the distance L2 (e.g., d) between the two receiving antennas RX1 and RX2, the ratio of the distance difference (e.g., dsin θ) between the distances of at least two sets of time-series adjacent time-series echo signals arriving at the corresponding virtual receiving antennas to the distance L2 (e.g., d) between the two receiving antennas RX1 and RX2 is sin θ. Alternatively, when the distance L2 between the two receiving antennas RX1 and RX2 (e.g., 2d) is twice the distance L1 between the two transmitting antennas TX1 and TX2 (e.g., d), the ratio of the distance difference between the distances at which at least two temporally adjacent time-sharing echo signals arrive at the corresponding virtual receiving antenna (e.g., dsin θ) to the distance L1 between the two transmitting antennas TX1 and TX2 (e.g., d) is sin θ. The arrival angle θ is the angle of the external object relative to the radar device 10, 20, or 30 degrees.

FIG6C is a schematic diagram of an antenna configuration and an equivalent virtual antenna according to another embodiment of the present invention. Referring to FIG4A and FIG6C, if the distance L1 (e.g., distance d) between two transmitting antennas TX1 and TX2 is the same as the distance L2 (e.g., distance d) between two receiving antennas RX1 and RX2, then these transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are equivalent to virtual transmitting antennas arranged in the same direction (e.g., horizontal direction of the figure). Virtual receiving antenna vTX1, virtual receiving antenna vRX1, virtual receiving antenna vRX2, and virtual receiving antenna vRX3 are provided. A first virtual distance (e.g., distance d) exists between virtual receiving antenna vRX1 and virtual receiving antenna vRX2, and a second virtual distance (e.g., distance d) exists between virtual receiving antenna vRX2 and virtual receiving antenna vRX3. Furthermore, the first virtual distance and the second virtual distance are equal. For example, both are distance d. d can be, but is not limited to, half the wavelength of the detection signal.

Similarly, at a first time (e.g., the first transmit/receive cycle), the time-sharing echo signal from virtual transmitting antenna vTX1 to virtual receiving antenna vRX1 has a phase difference in distance. At a second time (e.g., the second transmit/receive cycle), the propagation distance of the time-sharing echo signal from virtual transmitting antenna vTX1 to virtual receiving antenna vRX2 is greater by a distance dsin θ than the propagation distance of the time-sharing echo signal at the first time. At the third time (e.g., the third transmit/receive cycle), the propagation distance of the time-sharing echo signal from the virtual transmitting antenna vTX1 to the virtual receiving antenna vRX3 is one distance dsin θ greater than the propagation distance of the time-sharing echo signal at the second time. Therefore, the phase difference between two time-sharing echo signals that are adjacent in time sequence among the three time-sharing echo signals received at three times (e.g., three transmit/receive cycles) is The phase difference between these adjacent time-division echo signals can be defined as a uniform linear array of vectors a2(θ):

Figure 7A is a schematic diagram of an antenna configuration according to a third embodiment of the present invention. Referring to Figure 7A , multiple transmitting antennas 12 include two transmitting antennas TX1 and TX2 located in the X-Y/Y-X plane. A distance L3 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto) separates the two transmitting antennas TX1 and TX2. Multiple receiving antennas 13 include two receiving antennas RX1 and RX2 located in the X-Y/Y-X plane. A distance L4 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto) separates the two receiving antennas RX1 and RX2. Transmitting antennas TX1 and TX2 are arranged along an X-axis parallel to the X-Y plane or along a Y-axis parallel to the Y-X plane. The receiving antennas RX1 and RX2 are arranged along the Y-axis parallel to the X-Y plane or along the X-axis parallel to the Y-X plane. That is, the transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are arranged perpendicular to each other. In the embodiment of Figure 7A , the receiving antennas RX1 and RX2 are not aligned with the transmitting antennas TX1 or TX2. Thus, the transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 form a T-shaped arrangement, for example.

Figure 7B is a schematic diagram of an antenna configuration according to a fourth embodiment of the present invention. Referring to Figure 7B , the plurality of transmitting antennas 12 include two transmitting antennas TX1 and TX2 located in the X-Y/Y-X plane. A distance L5 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto) separates the two transmitting antennas TX1 and TX2. The plurality of receiving antennas 13 include two receiving antennas RX1 and RX2 located in the X-Y/Y-X plane. A distance L6 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto) separates the two receiving antennas RX1 and RX2. The transmitting antennas TX1 and TX2 are arranged along a Y-axis parallel to the X-Y plane or along an X-axis parallel to the Y-X plane. The receiving antennas RX1 and RX2 are arranged along the X-axis parallel to the X-Y plane or along the Y-axis parallel to the Y-X plane. That is, the transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are arranged perpendicular to each other. In the embodiment of Figure 7B , the receiving antennas RX1 and RX2 can be arranged in the same direction as the transmitting antenna TX1. In this way, the transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 form an L-shaped arrangement, for example.

Figure 8 is a schematic diagram illustrating the antenna configuration, transmission angle, and arrival angle according to an embodiment of the present invention. Referring to Figure 8 , radar devices 20 and 30 can transmit signals to external objects (also referred to as targets) via transmitting antenna TX1. Receiving antennas RX1 and RX2 receive echo signals reflected from the external objects. Assume that in the X-Z plane, the two receiving antennas RX1 and RX2 are separated by a distance d (e.g., half the wavelength of the detection signal). Receiving antenna RX2 is farther from transmitting antenna TX1 than from receiving antenna RX1. Therefore, the round-trip distance from transmitting antenna TX1, through the external object, to receiving antenna RX1 differs from the round-trip distance from transmitting antenna TX1, through the external object, to receiving antenna RX2 by dsinφ. The distance difference dsin φ is reflected in the phase difference between the echo signals from the two receiving antennas RX1 and RX2, and the angle of arrival φ can be estimated based on this difference. In other words, compared to the antenna configurations in Figures 4A and 4B, the antenna configurations in Figures 7A and 7B can also sense position information in another dimension (e.g., distance and azimuth (i.e., angle of arrival φ)).

Figure 9 is a schematic diagram illustrating the periods of detection signals TS1 and TS2 and antenna switching according to an embodiment of the present invention. Referring to Figure 9 , the detection signal is, for example, a continuous wave signal expressed in the form of a chirp signal. In this example, detection signal TS1 is a triangular wave. Alternatively, in another example, detection signal TS2 is a sawtooth wave. A frame time includes four transmit/receive cycles. Each transmit/receive cycle may include, for example, two cycles of detection signal TS1 or four cycles of detection signal TS2.

Similarly, the switching circuits 161 and 162 of the selection circuit 16 are used to select only one of the multiple transmitting antennas 12 (in this embodiment, transmitting antennas TX1 and TX2) to transmit a transmission signal in each transmit/receive cycle during a frame time, and to select only one of the multiple receiving antennas 13 (in this embodiment, receiving antennas RX1 and RX2) to receive an echo signal in each transmit/receive cycle during a frame time, according to one or more control signals. That is, during a transmit/receive cycle, the switching circuit 161 of the selection circuit 16 only turns on/selects one transmit antenna 12 (i.e., selects TX1 or TX2), effectively interrupting the signal transmitted by the transmit circuit 11 to the other transmit antennas. Furthermore, the switching circuit 162 of the selection circuit 16 only turns on/selects/uses one receive antenna 13 (i.e., selects RX1 or RX2), effectively interrupting the signal transmitted by the other receive antennas to the receive circuit 14. During this transmit/receive cycle, the transmit antenna 12 (TX1 or TX2) and the receive antenna 13 (RX1 or RX2) that are turned on/selected/used form a transmit/receive combination.

In one embodiment, in the second operating mode, a frame time includes four transceiver cycles. These four transceiver cycles include a first transceiver cycle, a second transceiver cycle, a third transceiver cycle, and a fourth transceiver cycle. These transceiver cycles correspond to multiple transceiver combination TRCs, with one transceiver cycle corresponding to one transceiver combination TRC. The switching circuits 161 and 162 of the selection circuit 16 select the transmitting antenna TX1 and the receiving antenna RX1 in the first transceiver cycle (corresponding to the transceiver pairing combination TRC of "TX1+RX1"), select the transmitting antenna TX1 and the receiving antenna RX2 in the second transceiver cycle (corresponding to the transceiver pairing combination TRC of "TX1+RX2"), select the transmitting antenna TX2 and the receiving antenna RX2 in the third transceiver cycle (corresponding to the transceiver pairing combination TRC of "TX2+RX2"), and select the transmitting antenna TX2 and the receiving antenna RX1 in the fourth transceiver cycle (corresponding to the transceiver pairing combination TRC of "TX2+RX1"). In other embodiments, the operations of the four transmit and receive cycles described above may be reversed in timing based on component configuration, signal transmission, or data computation requirements.

In this way, transmitting antennas TX1 and TX2 take turns transmitting signals, and receiving antennas RX1 and RX2 take turns receiving echo signals, thus achieving the effect of one transmitting antenna and four receiving antennas.

Figure 10A is a schematic diagram of an antenna configuration according to a fifth embodiment of the present invention. Referring to Figure 10A , the plurality of transmitting antennas 12 include two transmitting antennas TX1 and TX2 located in the X-Y/Y-X plane. A distance L7 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto) separates the two transmitting antennas TX1 and TX2. The plurality of receiving antennas 13 include two receiving antennas RX1 and RX2 located in the X-Y/Y-X plane. A distance L8 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto) separates the two receiving antennas RX1 and RX2. The transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are arranged along an X-axis parallel to the X-Y plane or along a Y-axis parallel to the Y-X plane. That is, the transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are arranged in the same direction. Transmitting antenna TX1 is closer to receiving antennas RX1 and RX2 than transmitting antenna TX2; and receiving antenna RX1 is closer to transmitting antennas TX1 and TX2 than receiving antenna RX2. Along the Y-axis parallel to the X-Y plane or along the X-axis parallel to the Y-X plane, the distance between transmitting antennas TX1/TX2 and receiving antennas RX1/RX2 is zero (i.e., they are arranged along an imaginary straight line parallel to the X-axis or along the Y-X plane). In one embodiment, distance L7 is twice distance L8. In other embodiments, distances L7 and L8 may have other ratios depending on the application scenario.

The difference between the embodiment shown in Figure 4A and Figure 10B is that Figure 10B is a schematic diagram of the radiation pattern in Figure 10A . Referring to Figure 10B , the beam pattern B1 formed by transmitting antenna TX1 differs from the beam pattern B2 formed by transmitting antenna TX2. As shown, beam pattern B1 is oriented slightly toward the lower left of the figure, while beam pattern B2 is oriented slightly toward the lower right of the figure. However, the shape and orientation of the beam pattern can be adjusted according to actual needs.

Figure 11A is a schematic diagram of an antenna configuration according to a sixth embodiment of the present invention. Referring to Figure 11A , the plurality of receiving antennas 13 include two receiving antennas RX1 and RX2 located in the X-Y/Y-X plane. A distance L9 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto) separates the two receiving antennas RX1 and RX2. The plurality of transmitting antennas 12 include two transmitting antennas TX1 and TX2 located in the X-Y/Y-X plane. A distance L10 (e.g., half the wavelength of the detection signal or the same wavelength, but not limited thereto) separates the two transmitting antennas TX1 and TX2. The transmitting antennas TX1 and TX2 and the receiving antennas RX1 and RX2 are arranged along an X-axis parallel to the X-Y plane or along a Y-axis parallel to the Y-X plane. Along the Y-axis parallel to the X-Y plane or the X-axis parallel to the Y-X plane, there is a distance (defined by the designer) between the transmitting antennas TX1/TX2 and the receiving antennas RX1/RX2. As shown in Figure 11A, antennas RX1/RX2 are, for example, farther from the X-axis parallel to the X-Y plane or the Y-axis parallel to the Y-X plane than transmitting antennas TX1/TX2. In one embodiment, distance L10 is twice distance L9. In other embodiments, distances L9 and L10 may have other ratios depending on the application scenario.

The difference between the embodiment shown in Figure 4A and Figure 11B is that Figure 11B is a schematic diagram of the radiation pattern in Figure 11A. Referring to Figure 11B , the beam patterns B3 and B4 formed by transmitting antenna TX1 differ from the beam pattern (e.g., omnidirectional) formed by transmitting antenna TX2. As shown, beam pattern B3 is slightly toward the lower left of the figure and has an elongated shape, covering a longer and narrower range. Beam pattern B4 is slightly toward the right of the figure and has a flatter shape, covering a shorter and wider range. However, the shape and orientation of the beam pattern can be adjusted according to actual needs.

It should be noted that Figures 10A and 11A are applicable to the second operating mode shown in Figure 9 and will not be further described here. This allows for a more diverse radiation pattern.

Figure 12 is a block diagram of components of a radar device 40 according to an embodiment of the present invention. Referring to Figure 12 , the difference between the radar device 10 and Figure 1 is that the radar device 40 further includes an I/Q (in-phase/quadrature) detection circuit 173. The detection circuit 173 is coupled to the receiving circuit 14. For example, the detection circuit 173 can receive the baseband signal DO output by the analog-to-digital converter ADC in the receiving circuit 14 of Figures 2A or 2B.

The frequencies of the intermediate frequency signals (e.g., the output signals of the mixer RXMIX in FIG. 2A or FIG. 2B ) obtained by the two receiving antennas 13 (e.g., the receiving antennas RX1 and RX2 in FIG. 2A or FIG. 2B ) are f _{IF 1} = f _{IF 2} = | f _RF - f _LO |, and their phases are respectively and .in, and , f _{IF 1} is the frequency of the intermediate frequency signal corresponding to the receiving antenna RX1, f _{IF 2} is the frequency of the intermediate frequency signal corresponding to the receiving antenna RX2, f _RF is the frequency of the radio frequency signal, f _LO is the frequency of the detection signal, is the phase of the intermediate frequency signal corresponding to the receiving antenna RX1, is the phase of the intermediate frequency signal corresponding to the receiving antenna RX2. is the phase of the RF signal corresponding to the receiving antenna RX1, is the phase of the RF signal corresponding to the receiving antenna RX2, To detect the phase of the signal, is the phase of the RF signal, and The phase of the IF signal (optionally, and in the case of relatively short-range detection, this can be ignored). Detection circuit 173 can then downconvert the IF signal with another I/Q format to determine its phase information. Alternatively, for FMCW signals, phase information can be obtained based on time delay by performing a fast Fourier transform.

It's worth noting that the phase error between the transmit antennas TX1/TX2 and the receive antennas RX1/RX2 can be measured using existing IF self-leakage and stored for phase error compensation. As shown in Figure 2A, a loopback architecture is used to simulate leakage at the receiver. Correction circuit IFA-2 corrects the IF signal output by the mixer RXMIX using a sine wave signal with a phase corresponding to the leakage, thereby reducing the phase error.

Figure 13 is a flowchart of spatial information determination according to an embodiment of the present invention. Referring to Figure 13 , radar devices 10, 20, 30, and 40 may transmit a transmission signal (step 1310). Based on the antenna configurations and corresponding operating modes (e.g., the first and second operating modes described above) shown in Figures 4A, 4B, 7A, 7B, 10A, and 11A, the transmitting antenna 12 in the corresponding transceiver combination is selected to transmit the transmission signal, and the receiving antenna 13 in the corresponding transceiver combination is selected to receive the echo signal. A virtual transceiver combination is then established (step 1320). For example, a virtual transceiver combination is the combination of virtual transmitting antenna vTX1 and virtual receiving antennas vRX1 to vRX4 or virtual receiving antennas vRX1 to vRX3 shown in Figures 6B and 6C. In other words, multiple transceiver combinations are achieved by using two physical transmitting antennas TX1 and TX2 and two receiving antennas RX1 and RX2 in a time-sharing manner to create a virtual transceiver combination of one virtual transmitting antenna and four virtual receiving antennas, or one virtual transmitting antenna and three virtual receiving antennas.

Next, radar devices 10, 20, 30, and 40 convert each time-sharing echo signal into frequency spectrum information to determine distance information (step 1330). Different radio frequency signals are generated for the time-sharing echo signals corresponding to different transmission and reception periods. The receiving circuit 14 generates corresponding internal signals (e.g., the aforementioned baseband signal DO) based on the detection signal and these different radio frequency signals.

Taking a frame including four transceiver cycles as an example, the receiving circuit 14 may generate a first internal signal corresponding to the first transceiver cycle, a second internal signal corresponding to the second transceiver cycle, a third internal signal corresponding to the third transceiver cycle, and a fourth internal signal corresponding to the fourth transceiver cycle.

Taking a frame including three transceiver cycles as an example, the receiving circuit 14 may generate a first internal signal corresponding to the first transceiver cycle, the receiving circuit 14 may generate a second internal signal corresponding to the second transceiver cycle, and the receiving circuit 14 may generate a third internal signal corresponding to the third transceiver cycle.

FIG14 is a schematic diagram of signal processing according to an embodiment of the present invention. Referring to FIG14 , the radar devices 10 to 40 may further include an operational processor 50. The operational processor 50 may, for example, be coupled to the receiving circuit 14 of FIG1 , FIG2A , or FIG2B . Taking FIG2A and FIG2B as examples, the operational processor 50 is coupled to the analog-to-digital converter ADC in the receiving circuit 14 and receives the baseband signal DO. The operational processor 50 may be a chip, a processor, a microcontroller, an application-specific integrated circuit (ASIC), or any other type of digital circuit. It should be noted that the transmitting circuit 11 is omitted between the switching circuit 161 and the operational processor 50 shown in FIG14 , and the receiving circuit 114 is omitted between the switching circuit 162 and the operational processor 50. Wherein, x _{0 ,n} ( t ) is the echo signal (time domain) received by the receiving antenna RX1, x _{1 ,n} ( t ) is the echo signal (time domain) received by the receiving antenna RX2, v _n ( m ) is the baseband signal (time domain) (i.e., internal signal), FFT stands for fast Fourier transform, and V _n ( k ) is the baseband signal (frequency domain). In addition, u _{0 ,n} ( k ) is the baseband signal (frequency domain) corresponding to the receiving antenna RX1, and u _{1 ,n} ( k ) is the baseband signal (frequency domain) corresponding to the receiving antenna RX2. The operation processor 50 performs high-pass filtering on the baseband signals u _{0 ,n} ( k ) and u _{1 ,n} ( k ) respectively to extract the positive frequency part (0 ω<π). The processor 50 then performs conjugate operations , multiplications , and linear combinations on the baseband signals S 0 _{, n} ( k ) and S _{1 ,n (} k ) to generate evaluation signals Y 0 _,n ( k ) and Y _{1 ,n} ( k ).

In one embodiment, for a frame consisting of four transmit/receive cycles (i.e., corresponding to four time-sharing transmit/receive combinations), the computational processor 50 may determine the spatial information of an external object based on the first internal signal, the second internal signal, the third internal signal, and the fourth internal signal. In another embodiment, for a frame consisting of three transmit/receive cycles (i.e., corresponding to three time-sharing transmit/receive combinations), the computational processor 50 may determine the spatial information of an external object based on the first internal signal, the second internal signal, and the third internal signal.

In one embodiment, the spatial information of the external object includes distance information. The computational processor 50 can obtain spectral information of the baseband signal DO corresponding to different internal signals through fast Fourier transform, discrete Fourier transform (DFT), or other time-domain to frequency domain conversion. The amplitude of the spectral information corresponds to the distance information. Taking a power spectrum as an example, assuming that the echo signal is reflected by an external object, each internal signal will have a peak at the location of the external object (or at its distance from the external object).

Taking four transceiver combinations as an example, if there are K external objects (K is a positive integer) located at the same position (i.e., the same beat frequency, and the beat frequency is the peak position in the spectrum), then the internal signals corresponding to the four transceiver combinations are sequentially converted from the time domain to the frequency domain (for example, discrete or fast Fourier transform), conjugate operation, product and linear combination to obtain the evaluation signal 、 、 、 They are:

, where ω ^{( B )} is the beat frequency (assuming they are at the same distance, so their values are the same), A is the amplitude of the reflected power associated with the external object, R is the distance between the external object and the transmitting antenna 12 or the receiving antenna 13 (which can be used as distance information, as shown in Figure 6A), θ is the angle of the external object relative to the receiving antenna 13, H ₀ (ω) and H ₁ (ω) are , M is the number of sampled signals in one detection signal cycle, E(θ) is the parameter corresponding to the antenna beam radiation pattern, N ₀ and N ₁ are noise, Y _{0, t 1} is the internal signal obtained by the receiving antenna RX1 during the transceiver cycle t1, Y _{1, t 2} is the internal signal obtained by the receiving antenna RX2 during the transceiver cycle t2, Y _{0, t 3} is the internal signal obtained by the receiving antenna RX1 during the transceiver cycle t3, and Y _{1, t 4} is the internal signal obtained by the receiving antenna RX2 during the transceiver cycle t4.

The above formulas (5) to (8) can be converted into matrix form: ,in , a(θ)= , n is the noise. Thus, the computation processor 50 can estimate the distance R and, accordingly, derive the distance information. Because the method of this embodiment sets the phase difference between at least two sets of temporally adjacent time-sharing echo signals to be equal, the computation is simplified and more convenient, reducing the computation time of the computation processor 50 and improving the efficiency of the radar device 10-40.

On the other hand, the computing processor 50 can determine the presence of an external object by setting an amplitude threshold (step 1340) and, accordingly, determine the number of external objects (step S1350). In one embodiment, the number of one or more external objects can be determined based on spectral information. For example, the spectral information can be a power spectrum. If the peak value corresponding to any distance is greater than the amplitude threshold, the presence of an external object is determined. It is determined whether the peak value corresponding to different distances is greater than the amplitude threshold, and the number of peaks greater than the amplitude threshold is counted. The number of peaks greater than the amplitude threshold can be used as the number of external objects.

Furthermore, the computational processor 50 may convert the multiple time-sharing echo signals into spatial spectrum information to determine azimuth information (step 1360). A peak in the spatial spectrum information corresponds to azimuth information, and the spatial information includes azimuth information. The azimuth information may be, for example, the aforementioned angle of arrival θ or angle of arrival φ. Taking equation (9) as an example, its covariance matrix may be expressed as: , where σ ² is the noise variance (or noise power), and I is a unit matrix. Thus, the computational processor 50 can estimate the arrival angles θ ₁ -θ _K of the first to Kth external objects and derive their orientation information accordingly.

For example, if K=2 (i.e., two external objects), , θ ₁ and θ ₂ are the orientation information (e.g., angle of arrival) corresponding to the two external objects.

Angle of arrival (AoA) estimation algorithms include the Multiple Signal Classification Algorithm (MUSIC), the Root-MUSIC algorithm, or the Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) algorithm.

Taking MUSIC as an example, assuming K = 1 (i.e., one external object), formula (10) can be transformed into:

The 4×4 symmetric matrix H has a positive eigenvalue λ ₁ . Defining q ₁ as the eigenvector corresponding to eigenvalue λ ₁ , we can obtain: H. q ₁ =λ ₁ . _{q 1} ...(13), where the maximum eigenvalue of R _uu corresponding to eigenvector q ₁ in signal space is (λ ₁ + σ ² ).

Define other eigenvalues λ ₂ , λ ₃ , λ ₄ and assign them the same noise variance σ ² , then the corresponding eigenvectors q ₂ , q ₃ , q ₄ satisfy: H. [q ₂ q ₃ q ₄ ] = [0 0 0]...(14), where a ^H (θ ₁ )． [q ₂ q ₃ q ₄ ] = [0 0 0].

These eigenvectors q ₂ , q ₃ , and q ₄ are located in the null space of the signal. Taking the inner product of these with the vector a(θ) is: L(θ) = |a ^H (θ) [q ₂ q ₃ q ₄ ] | ² ...(15).

The evaluation function L(θ) is defined as 0 when θ=θ ₁ , and its eigenspectrum can be defined as: , and S(θ) has a peak when θ=θ ₁ .

FIG15 is a flow chart of a signal transceiver method according to an embodiment of the present invention. Referring to FIG1 and FIG15 , a transmission signal is generated based on a detection signal (step S1510), wherein the detection signal exhibits periodic variations. For example, the detection signal TS1 in FIG5 may be presented as a triangular wave with varying frequency, while the detection signal TS2 may be presented as a sawtooth wave with varying frequency. Alternatively, the detection signal may be a periodic pulse signal. Based on the period of the detection signal, one or more control signals are generated (step S1520). For example, these may be the control signals TSSC and RXSC shown in FIG5 or FIG9 . Based on one or more control signals, one of the plurality of transmitting antennas is selected to transmit a transmission signal, and one of the plurality of receiving antennas is selected to receive an echo signal to generate a radio frequency signal (step S1530). The echo signal is generated by the transmission signal being reflected by an external object. An internal signal is generated based on the detection signal and the radio frequency signal (step S1540).

In one embodiment, within a frame time, multiple transmit-receive combinations executed according to one or more control signals at different times (for example, different transmit-receive cycles) correspond to multiple time-sharing echo signals. Each transmit-receive combination includes a combination of one of the multiple transmitting antennas 12 and one of the multiple receiving antennas 13. For example, "TX1+RX1", "TX1+RX2", "TX2+RX1" and "TX2+RX2" shown in Figure 5. The time-sharing echo signal includes the echo signals received at different times (for example, different transmit-receive cycles) in this frame time. The phase difference between at least two sets of time-series adjacent time-sharing echo signals in these time-sharing echo signals is equal. For example, the phase difference is .

The implementation details of each step in Figure 15 are fully described in the aforementioned embodiments and implementation methods and will not be repeated here. In addition to implementation in the form of circuits, the steps and implementation details of the embodiments of the present invention can also be implemented in software by a processor, and the embodiments of the present invention are not limited to this.

In summary, the radar device and signal transceiver method of the embodiments of the present invention sequentially transmit and receive signals through a time-sharing combination of transmission and reception. Applied to a configuration of two transmitting antennas and two receiving antennas, this can achieve the effect of one virtual transmitting antenna and three virtual receiving antennas, or one virtual transmitting antenna and four virtual receiving antennas. This reduces power consumption, the size of the antenna structure or chip, and phase error. Compared to a configuration of one transmitting antenna and two receiving antennas, it can also clearly identify different external objects at the same distance relative to the receiving antenna. Furthermore, in embodiments using multiple transmitting antennas in a time-sharing manner and multiple receiving antennas simultaneously, it can also achieve the effect of reducing some power consumption and some antenna structure or chip size. Furthermore, in embodiments where the phase difference between at least two sets of temporally adjacent time-sharing echo signals is set equal, computations can be simplified and more convenient, reducing computation time and improving the efficiency of the radar device.

Although the present invention has been disclosed above through embodiments, they are not intended to limit the present invention. Anyone with ordinary skill in the art may make minor modifications and improvements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the attached patent application.

10: Radar Device 11: Transmitter Circuit 12: Transmitter Antenna 13: Receiver Antenna 14: Receiver Circuit 15: Controller Selection 16: Circuit Selection

Claims (20)

A radar device includes: a transmitting circuit for generating a transmission signal based on a detection signal, wherein the detection signal has a periodic variation; a plurality of transmitting antennas for transmitting the transmission signal; a plurality of receiving antennas for receiving an echo signal, wherein the echo signal is generated by the transmission signal being reflected by an external object; a receiving circuit for generating an internal signal based on the detection signal and a radio frequency signal; a selection controller coupled to the transmitting circuit and configured to generate one or more control signals based on the period of the detection signal; and A selection circuit is coupled to the transmitting antennas, the receiving antennas, the transmitting circuit, the receiving circuit, and the selection controller, and is configured to select one of the transmitting antennas to transmit the transmission signal and one of the receiving antennas to receive the echo signal to generate the radio frequency signal based on the one or more control signals generated by the selection controller; wherein Within a frame time, multiple transmit/receive combinations executed at different times in accordance with the one or more control signals correspond to multiple time-sharing echo signals. The phase difference between at least two sets of temporally adjacent time-sharing echo signals in the time-sharing echo signals is equal. The time-sharing echo signals include the echo signals received at different times within the frame time. Each transmit/receive combination comprises a combination of one of the transmitting antennas and one of the receiving antennas. The radar device as described in claim 1, wherein the frame time includes a plurality of transmit/receive cycles, the transmit/receive cycles respectively corresponding to the transmit/receive combinations, and the transmit/receive cycles corresponding to the cycles of the detection signal; the selection circuit is configured to select only one of the transmitting antennas to transmit the transmission signal in each transmit/receive cycle in the frame time, and to select only one of the receiving antennas to receive the echo signal in each transmit/receive cycle in the frame time, based on the one or more control signals. In the radar device as described in claim 2, the transmitting antennas and the receiving antennas are arranged in the same direction. The radar device as described in claim 3, wherein the transmitting antennas include a first transmitting antenna and a second transmitting antenna, and the receiving antennas include a first receiving antenna and a second receiving antenna, wherein a first distance exists between the first transmitting antenna and the second transmitting antenna, and a second distance exists between the first receiving antenna and the second receiving antenna, and wherein the first distance is twice the second distance or the second distance is twice the first distance. The radar device as described in claim 4, wherein the first transmitting antenna, the second transmitting antenna, the first receiving antenna, and the second receiving antenna equivalently generate a first virtual transmitting antenna, a first virtual receiving antenna, a second virtual receiving antenna, a third virtual receiving antenna, and a fourth virtual receiving antenna arranged in the same direction, and the first There is a first virtual distance between the virtual receiving antenna and the second virtual receiving antenna, a second virtual distance between the second virtual receiving antenna and the third virtual receiving antenna, and a third virtual distance between the third virtual transmitting antenna and the fourth virtual receiving antenna. The first virtual distance, the second virtual distance, and the third virtual distance are equal. The radar device as described in claim 5, wherein when the first spacing is twice the second spacing, the ratio of the distance difference between at least two sets of temporally adjacent time-sharing echo signals from reaching the corresponding virtual receiving antenna to the second spacing is sinθ; or, when the second spacing is twice the first spacing, the ratio of the distance difference between at least two sets of temporally adjacent time-sharing echo signals from reaching the corresponding virtual receiving antenna to the first spacing is sinθ, where θ is the angle of the external object relative to the radar device. The radar device as described in claim 4, wherein the first transmitting antenna, the second transmitting antenna, the first receiving antenna, and the second receiving antenna are spatially arranged sequentially in a row along the same direction, the frame time includes a first transceiver cycle, a second transceiver cycle, a third transceiver cycle, and a fourth transceiver cycle arranged in time sequence, and the selection circuit is configured to select the first transmitting antenna and the first receiving antenna in the first transceiver cycle, select the first transmitting antenna and the second receiving antenna in the second transceiver cycle, select the second transmitting antenna and the first receiving antenna in the third transceiver cycle, and select the second transmitting antenna and the second receiving antenna in the fourth transceiver cycle based on the one or more control signals. The radar device as described in claim 7 further includes an operational processor coupled to the receiving circuit, wherein the receiving circuit generates a first internal signal corresponding to the first transceiver cycle, generates a second internal signal corresponding to the second transceiver cycle, generates a third internal signal corresponding to the third transceiver cycle, and generates a fourth internal signal corresponding to the fourth transceiver cycle. The internal signals include the first internal signal, the second internal signal, the third internal signal, and the fourth internal signal. The operational processor is configured to determine spatial information of the external object based on the first internal signal, the second internal signal, the third internal signal, and the fourth internal signal. The radar device as described in claim 3, wherein the transmitting antennas include a first transmitting antenna and a second transmitting antenna, the receiving antennas include a first receiving antenna and a second receiving antenna, the first transmitting antenna and the second transmitting antenna have a first distance therebetween, the first receiving antenna and the second receiving antenna have a second distance therebetween, the first distance being the same as the second distance, wherein the first transmitting antenna, the second transmitting antenna, The first receiving antenna and the second receiving antenna equivalently generate a first virtual transmitting antenna, a first virtual receiving antenna, a second virtual receiving antenna, and a third virtual receiving antenna arranged in the same direction. There is a first virtual distance between the first virtual receiving antenna and the second virtual receiving antenna, and there is a second virtual distance between the second virtual receiving antenna and the third virtual receiving antenna. The first virtual distance is equal to the second virtual distance. The radar device as described in claim 1 further includes: a frequency synthesizer for generating the detection signal, the detection signal being a carrier signal, wherein the selection controller is coupled to the transmitting circuit via the frequency synthesizer; or a pulse generator for generating the detection signal, the detection signal being a pulse signal, wherein the selection controller is coupled to the transmitting circuit via the pulse generator. A signal transmission and reception method includes: generating a transmission signal based on a detection signal, wherein the detection signal varies periodically; generating one or more control signals based on the period of the detection signal; selecting one of a plurality of transmitting antennas to transmit the transmission signal and one of a plurality of receiving antennas to receive an echo signal to generate a radio frequency signal based on the one or more control signals, wherein the echo signal is generated by the transmission signal being reflected by an external object; generating an internal signal based on the detection signal and the radio frequency signal; Within a frame time, multiple transmit/receive combinations executed at different times in accordance with the one or more control signals correspond to multiple time-sharing echo signals. The phase difference between at least two sets of temporally adjacent time-sharing echo signals in the time-sharing echo signals is equal. The time-sharing echo signals include the echo signals received at different times within the frame time. Each transmit/receive combination comprises a combination of one of the transmitting antennas and one of the receiving antennas. The signal transceiver method as described in claim 11, wherein the frame time includes a plurality of transceiver cycles, the transceiver cycles respectively corresponding to the transceiver combinations, the transceiver cycles corresponding to the detection signal cycle, and wherein the step of selecting one of the transmitting antennas to transmit the transmission signal and one of the receiving antennas to receive the echo signal based on the one or more control signals comprises: Based on the one or more control signals, selecting only one of the transmitting antennas to transmit the transmission signal in each of the transceiver cycles within the frame time, and selecting only one of the receiving antennas to receive the echo signal in each of the transceiver cycles within the frame time. The signal transceiver method described in claim 12 further includes arranging the transmitting antennas and the receiving antennas in the same direction. The signal transceiver method as described in claim 13, wherein the transmitting antennas include a first transmitting antenna and a second transmitting antenna, and the receiving antennas include a first receiving antenna and a second receiving antenna, the first transmitting antenna and the second transmitting antenna are spaced apart by a first distance, and the first receiving antenna and the second receiving antenna are spaced apart by a second distance, wherein the signal transceiver method further includes making the first distance twice the second distance or the second distance twice the first distance. The signal transceiver method as described in claim 14 further includes causing the first transmitting antenna, the second transmitting antenna, the first receiving antenna, and the second receiving antenna to equivalently generate a first virtual transmitting antenna, a first virtual receiving antenna, a second virtual receiving antenna, a third virtual receiving antenna, and a fourth virtual receiving antenna arranged in the same direction, wherein There is a first virtual distance between the first virtual receiving antenna and the second virtual receiving antenna, a second virtual distance between the second virtual receiving antenna and the third virtual receiving antenna, and a third virtual distance between the third virtual transmitting antenna and the fourth virtual receiving antenna. The first virtual distance, the second virtual distance, and the third virtual distance are equal. The signal transceiver method as described in claim 15 further includes: when the first spacing is twice the second spacing, the ratio of the distance difference between at least two sets of temporally adjacent time-sharing echo signals from the time-sharing echo signals arriving at the corresponding virtual receiving antenna to the second spacing is sinθ; or when the second spacing is twice the first spacing, the ratio of the distance difference between at least two sets of temporally adjacent time-sharing echo signals from the time-sharing echo signals from the time-sharing echo signals arriving at the corresponding virtual receiving antenna to the first spacing is sinθ, where θ is the angle of the external object relative to the radar device. The signal transceiver method as described in claim 14, wherein the first transmitting antenna, the second transmitting antenna, the first receiving antenna, and the second receiving antenna are spatially arranged in a row in the same direction, the frame time includes a first transceiver cycle, a second transceiver cycle, a third transceiver cycle, and a fourth transceiver cycle arranged in time sequence, and wherein the steps of selecting only one of the transmitting antennas to transmit the transmission signal in each transceiver cycle in the frame time and selecting only one of the receiving antennas to receive the echo signal in each transceiver cycle in the frame time to generate the radio frequency signal according to the one or more control signals include: The first transmitting antenna and the first receiving antenna are selected according to the one or more control signals in the first transceiver cycle, the first transmitting antenna and the second receiving antenna are selected in the second transceiver cycle, the second transmitting antenna and the first receiving antenna are selected in the third transceiver cycle, and the second transmitting antenna and the second receiving antenna are selected in the fourth transceiver cycle. The signal transceiver method of claim 17 further includes: Generating a first internal signal corresponding to the first transceiver cycle, generating a second internal signal corresponding to the second transceiver cycle, generating a third internal signal corresponding to the third transceiver cycle, and generating a fourth internal signal corresponding to the fourth transceiver cycle, wherein the internal signals include the first internal signal, the second internal signal, the third internal signal, and the fourth internal signal, and are used to determine spatial information of the external object based on the first internal signal, the second internal signal, the third internal signal, and the fourth internal signal. The signal transceiver method of claim 11 further comprises: Converting each of the time-division echo signals into spectral information, wherein the amplitude of the spectral information corresponds to distance information, and the spatial information includes the distance information; Determining the number of one or more external objects based on the spectral information; and Converting the time-division echo signals into spatial spectral information, wherein a peak in the spatial spectral information corresponds to direction information, and the spatial information includes the direction information. A radar device includes: a transmitting circuit for generating a transmission signal based on a detection signal, wherein the detection signal has a periodic variation; a plurality of transmitting antennas for transmitting the transmission signal; a plurality of receiving antennas for receiving an echo signal, wherein the echo signal is generated by the transmission signal being reflected by an external object; a receiving circuit for generating an internal signal based on the detection signal and a radio frequency signal; a selection controller coupled to the transmitting circuit and configured to generate one or more control signals based on the period of the detection signal; and A selection circuit is coupled to the transmitting antennas, the receiving antennas, the transmitting circuit, the receiving circuit, and the selection controller, and is configured to select one of the transmitting antennas to transmit the transmission signal and one of the receiving antennas to receive the echo signal to generate the radio frequency signal based on the one or more control signals generated by the selection controller. The transmitting antennas include a first transmitting antenna and a second transmitting antenna, and the receiving antennas include a first receiving antenna and a second receiving antenna. The first transmitting antenna and the second transmitting antenna have a first distance therebetween, and the first receiving antenna and the second receiving antenna have a second distance therebetween. The first distance is twice the second distance, or the second distance is twice the first distance.