JP2011259092A - Signal transmission system, communication device, electronic device and signal transmission method - Google Patents

Abstract

To realize communication with low power consumption.
In a transmission chip 8001, a modulation function unit 8300 generates a radio signal based on a baseband signal, adjusts the magnitude of the generated radio signal by a transmission output amplification unit 8117, and transmits the radio signal to a reception chip 8002. To do. The receiving chip 8002 reproduces a baseband signal based on the radio signal received by the demodulation function unit 8400. A transmission output amplifying unit 8117 is used that consumes less power if the level of the output radio signal is lower, and increases if the level of the output radio signal is greater. The size of the radio signal to be transmitted is set so as to match the transmission characteristics between the transmission chip 8001 and the reception chip 8002. In performing communication, if the transmission output level is set to the minimum necessary level based on actual transmission characteristics, useless power consumption can be suppressed and unnecessary radiation can be suppressed.
[Selection] Figure 3

Description

  The present invention relates to a signal transmission system, a communication device, an electronic device, and a signal transmission method.

  In normal communication, the output level of the transmitter (referred to as a transmission output level) is maximized, and the range up to the distance at which the receiver has the lowest reception sensitivity level is a receivable region.

  In this case, the transmitter output is made constant at a large level, the signal is detected on the receiving side, and the gain is controlled in the receiver to obtain a constant baseband signal. Communication is at a higher transmission output level than necessary, and power consumption is large. Since the receiver needs to be able to receive even a strong input signal, a circuit with good linearity is required, and the power consumption of the receiver increases. When the transmission output is large, radiation to the outside increases.

  Incidentally, Patent Documents 1 to 3 disclose a mechanism for controlling the transmission output level.

JP 2008-510355 A JP 2006-144853 A JP 05-347565 A

  Patent Document 1 relates to a method of controlling uplink transmission power that reduces interference in a wireless communication system. For example, a base station controls a transmission output level of a mobile phone.

  In Patent Document 2, the distance is detected by electromagnetic coupling, and the output level of the WLAN is controlled.

  Patent Document 3 configures a transmission device so that the output level can be controlled, and its purpose is to prevent distortion during short-range communication, and its mechanism uses a variable attenuator with a resistance at the output section.

  An object of the present invention is to provide a mechanism for setting a transmission output level so as to realize communication with low power consumption.

  In the present invention, the transmission unit and the reception unit are arranged at predetermined locations in the electronic device, and the signal adjustment unit transmits the signal from the transmission unit to the reception unit according to the transmission characteristics between the transmission unit and the reception unit. The size of the radio signal to be transmitted is set, and the signal output from the signal adjustment unit is transmitted as a radio signal from the transmission unit to the reception unit.

  As the signal adjusting unit, a wireless signal transmitted from the transmitting unit is small if the level (amplitude) is small, and if the level is large, the power consumption is large. For this reason, if the transmission output level is set to a necessary minimum level based on actual transmission characteristics in communication, useless power consumption can be suppressed and unnecessary radiation can be suppressed.

  According to the present invention, the transmission output level can be set so as to realize low power consumption communication.

FIG. 1 is a diagram for explaining the overall outline of the signal transmission system of the present embodiment. FIG. 2 is a diagram for explaining the first embodiment. FIG. 3 is a diagram for explaining the details of the first embodiment. FIG. 4 is a diagram for explaining the second embodiment. FIG. 5 is a diagram for explaining a third embodiment (overall outline / first detailed configuration). FIG. 6 is a diagram for explaining the third embodiment (second detailed configuration). FIG. 7 is a diagram illustrating a first example of an electronic device. FIG. 8 is a diagram illustrating a second example of an electronic device. FIG. 9 is a diagram illustrating a third example of an electronic device. FIG. 10 is a diagram illustrating a modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. When distinguishing each functional element by form, an uppercase alphabetic reference is added, such as A, B, C,..., And this reference is omitted when it is not particularly distinguished. And describe. The same applies to the drawings.

The description will be made in the following order.
1. 1. Signal transmission system: overall overview First embodiment (fixed setting)
3. Second embodiment (feedback control)
4). Third embodiment (two-way communication, feedback control)
5). Application examples to electronic devices (1st to 3rd examples)

<Signal transmission system: Overview>
FIG. 1 is a diagram for explaining the overall outline of the signal transmission system of the present embodiment. The signal transmission system 1 of this embodiment is an example applied to the communication system 8. The signal transmission system 1 and the communication system 8 of the present embodiment are used in, for example, a digital recording / reproducing device, a terrestrial television receiver, a mobile phone device, a game device, a computer, and the like.

  The communication system 8 includes a plurality of communication devices 2 that transmit transmission target signals wirelessly. The example in the figure shows an example in which five communication devices 2_1 to 2_5 are accommodated in a casing of one electronic device. However, the number of communication devices 2 is not limited to five, and these are one electronic device. It is not indispensable to be housed in the housing.

  Incidentally, in this configuration example, the first transmission channel using the first carrier frequency f1 is configured by the communication device 2_1 and the communication device 2_2, and the second carrier frequency is configured by the communication device 2_3, the communication device 2_4, and the communication device 2_5. This is an example in which a second transmission channel using f2 is configured. That is, the frequency division multiplex transmission in which the transmission unit and the reception unit are transmitted using different carrier frequencies is performed, and the one-to-one first communication system 8_1 and the one-to-two second communication system 8_2 are provided. It is a mixed system configuration. Incidentally, the transmission channel only needs to be provided with at least one communication device 2 having a reception unit for one communication device 2 having a transmission unit. One or more.

  It is configured to perform signal transmission between a first communication unit that is an example of a first wireless device and a second communication unit that is an example of a second wireless device. And between the 1st communication part and the 2nd communication part arrange | positioned at a comparatively short distance, after converting the signal of transmission object into the high frequency signal (for example, millimeter wave signal) of a predetermined | prescribed frequency band, this A high frequency signal is transmitted via a predetermined wireless transmission path. The “wireless transmission” in the present embodiment means that a signal to be transmitted is transmitted wirelessly (for example, in the millimeter wave band) instead of a general electric wiring (simple wire wiring).

  “Relatively close” means that the distance is short compared to the distance between communication devices in the outdoors (outdoors) used in broadcasting and general wireless communication, and the transmission range is closed. Any material that can be substantially specified may be used. “Closed space” means a space where there is little leakage of radio waves from the inside of the space to the outside, and conversely, there is little arrival (intrusion) of radio waves from the outside to the inside of the space. The entire space is surrounded by a casing (case) that has a shielding effect against radio waves.

  For example, in-device signal transmission such as inter-board communication within a housing of one electronic device or inter-chip communication on the same substrate, or in a state where one electronic device is mounted with the other electronic device. This corresponds to signal transmission between devices in a state where electronic devices are integrated.

  “Integrated” is typically a state where both electronic devices are in complete contact with each other, but as described above, the transmission range between both electronic devices can be substantially specified as a closed space. I just need it. This includes the case where both electronic devices are arranged at a predetermined position in a state where they are somewhat separated (relatively close distance: for example, within several centimeters to several tens of centimeters) and can be regarded as being “substantially” integral. The point is that there is little leakage of radio waves from the inside of the space where the radio waves composed of both electronic devices can propagate, and conversely, the state where the arrival (intrusion) of radio waves from the outside to the inside of the space is small. .

  Hereinafter, signal transmission within a casing of one electronic device is referred to as signal transmission within the casing, and signal transmission in a state in which a plurality of electronic devices are integrated (hereinafter also including “substantially integrated”) is performed. This is called inter-signal transmission. In the case of signal transmission within the housing, the communication device on the transmission side (communication unit: transmission unit) and the communication device on the reception side (communication unit: reception unit) are accommodated in the same housing, and the communication unit (transmission unit and reception unit) The wireless transmission system of this embodiment in which a wireless signal transmission path is formed between them is an electronic device itself. On the other hand, in the case of signal transmission between devices, the communication device on the transmission side (communication unit: transmission unit) and the communication device on the reception side (communication unit: reception unit) are accommodated in different electronic device casings. When the electronic device is arranged at a predetermined position and integrated, a wireless signal transmission path is formed between the communication units (transmitting unit and receiving unit) in both electronic devices, and the wireless transmission system of this embodiment is constructed. The

  In each communication device provided with a high-frequency signal transmission path (for example, a millimeter wave signal transmission path) interposed therebetween, a transmission unit and a reception unit are paired and arranged. Signal transmission between one communication device and the other communication device may be one-way (one-way) or two-way. For example, when the first communication unit is the transmission side and the second communication unit is the reception side, the transmission unit is arranged in the first communication unit and the reception unit is arranged in the second communication unit. When the second communication unit is the transmission side and the first communication unit is the reception side, the transmission unit is arranged in the second communication unit and the reception unit is arranged in the first communication unit.

  The transmission unit, for example, performs signal processing on a signal to be transmitted to generate a high-frequency (for example, millimeter wave) signal (signal conversion unit that converts an electric signal to be transmitted into a high-frequency signal) A transmission-side signal coupling unit that couples a high-frequency signal generated by the transmission-side signal generation unit to a transmission path (high-frequency signal transmission path) for transmitting a high-frequency signal is provided. Preferably, the signal generator on the transmission side is integrated with a functional unit that generates a signal to be transmitted.

  For example, the signal generator on the transmission side has a modulation circuit, and the modulation circuit modulates a signal to be transmitted. The signal generator on the transmission side converts the frequency of the signal modulated by the modulation circuit to generate a high-frequency signal. In principle, it is conceivable to directly convert a signal to be transmitted into a high-frequency signal. The signal coupling unit on the transmission side supplies the high frequency signal generated by the signal generation unit on the transmission side to the high frequency signal transmission path.

  The receiving unit, for example, receives a high-frequency signal transmitted via a high-frequency signal transmission path and a high-frequency signal (input signal) received by the receiving-side signal combining unit and the receiving-side signal combining unit. A reception-side signal generation unit (a signal conversion unit that converts a high-frequency signal into a transmission-target electrical signal) that processes and generates a normal electrical signal (transmission-target signal) is provided. Preferably, the signal generation unit on the reception side is integrated with a function unit that receives a signal to be transmitted. For example, the signal generation unit on the reception side includes a demodulation circuit, generates a signal to be transmitted by frequency-converting a high-frequency signal to generate an output signal, and then the demodulation circuit demodulates the output signal. In principle, it is conceivable to directly convert a high-frequency signal into a signal to be transmitted.

  In other words, when taking a signal interface, a signal to be transmitted is transmitted by a high-frequency signal without a contact or a cable (not transmitted by electrical wiring). Preferably, at least signal transmission (especially a video signal or high-speed clock signal requiring high-speed transmission or large-capacity transmission) is transmitted by a high-frequency signal. In short, signal transmission that has been performed by electrical wiring in the past is performed by a high-frequency signal in this embodiment. By performing signal transmission in a high frequency band (for example, millimeter wave band), it becomes possible to realize high-speed signal transmission in the order of Gbps, and easy coverage of signals in a high frequency band (for example, millimeter wave band). The effect resulting from this property can also be obtained.

  For example, the communication device 2 includes a communication chip 8000. The communication chip 8000 may be either one or both of the transmission chip (TX) and the reception chip (RX), or may have both functions of the transmission chip and the reception chip in one chip and support bidirectional communication. Good.

  As will be described in detail later, a mechanism for managing transmission power is provided to configure the signal transmission system 1. The purpose is to arrange the transmitter / receiver so that it does not become an excessive level, an excessive level, or an SNR (Signal Noise Ratio: S / N) does not become an excessive level. By properly managing the transmission output level based on the transmission characteristics (communication environment) such as transmission distance and transmission path condition by the transmission, the transmission level is minimized and communication with low power consumption (more preferably less unnecessary radiation) Communication).

  As a mechanism for managing transmission power, various methods are considered from the viewpoint of whether to use fixed setting (so-called preset setting) or automatic control, and how to determine the setting level. It is done. Further, when there are a plurality of transmission channels as shown in the figure, when the transmission characteristics of the respective transmission channels are different (for example, the transmission distance between transmission and reception is different), the radio transmitted from the transmission unit of each transmission channel Set the signal size to be different.

  For example, the first form employs a technique of presetting the transmission output level based on transmission characteristics (communication environment) between transmission and reception. In that case, as a preferable aspect, a transmission characteristic index detection unit for detecting a state of transmission characteristics between a transmission chip as a transmission apparatus and a reception chip as a reception apparatus is provided, and a transmission characteristic index signal as a detection result is provided. Referring to, the transmission output level on the transmission chip side can be preset. For example, a transmission characteristic index detection unit is provided on the receiving chip side (the transmission characteristic index detection unit does not have to be built in the reception chip), detects the state of the received radio signal, and refers to the state detection signal that is the detection result Then, the transmission output level on the transmission chip side is preset. If there is a certain correspondence between the reception level and the SNR, such as when the reception level is excessive or too low, the SNR is reduced. Using the reception level as a determination index is equivalent to using the SNR as a determination index. In the case of a system configuration in which there is no fixed correspondence between the reception level and the SNR, level management focusing on the SNR may be considered, for example, using an error rate as a determination index instead of the reception level. That is, in the first mode, similarly to the second mode, a detection mechanism (transmission characteristic index detection unit) that detects a judgment index reflecting actual transmission characteristics such as a reception level and SNR is provided on the receiving chip side. Refer to the detection result and manually set the output level on the transmission side.

  Unlike the second embodiment, the first embodiment does not employ an automatic control mechanism, but is intended to refer to the reception level and SNR on the reception side as a determination index when presetting the transmission level. Since the reception level and SNR vary depending on the transmission characteristics such as the transmission distance and transmission path status depending on the arrangement of the transceiver, the reception level that reflects the actual transmission characteristics rather than directly judging the distance between transmission and reception And SNR are used as judgment indices to manage the transmission level.

  In other words, use a transmission chip with a variable transmission output level and lower power consumption by lowering the transmission output level, depending on transmission characteristics such as transmission distance and transmission path status depending on the arrangement of the transceiver The transmission output level is appropriately set so that the reception state becomes an appropriate state with reference to the reception level and SNR that change in response to the above.

  For example, when the reception level (that is, the reception strength) is high, the transmission output level is lowered, and when the reception level is low, the transmission output level is increased so that the reception level is not too high or too low. Set the output level.

  In the second embodiment, a detection mechanism (transmission characteristic index detection unit) that detects a judgment index reflecting actual transmission characteristics such as a reception level and SNR is provided on the receiving chip side, and a level detection signal that is a detection result is referred to. Thus, the transmission output level on the transmission chip side is feedback-controlled. Although it is arbitrary where the control unit for feedback control is arranged, it is preferable to arrange it on the transmission chip side as a preferable mode. The second mode is to configure a system by a transmitter, a receiver, and a control unit, and to automatically control the output level of the transmitter to an appropriate level based on the detection result of the transmission characteristic index detection unit. is there.

  Although it differs from the first embodiment in the point of automatic control by feedback, the purpose is not different from the first embodiment. That is, in both the first form and the second form, by setting the transmission output level to the minimum necessary level, the output amplifier is operated with low power consumption, thereby realizing low power consumption communication.

  In any case, the transmitter output level should be set to the minimum level in consideration of the communication environment (communication range, transmission path characteristics, etc.), and the transmitter output should be lowered to the minimum level. Therefore, the power consumption of the transmission output amplifier can be reduced. Communication with low power consumption can be realized by operating the transmission output amplifier with low power consumption. Since the input level to the receiver becomes a constant level, resistance to strong input can be relaxed and the power consumption of the receiver can also be reduced. Since the transmission output is at the necessary minimum level, radiation outside the device is also reduced.

  Incidentally, in the first embodiment, since feedback control is not performed, it cannot always be managed at an appropriate level when the communication environment changes. On the other hand, in the second embodiment, since feedback control is performed, even when the communication environment changes, it can always be managed at an appropriate level in response to the change.

  The third form is a case where a configuration corresponding to bidirectional communication is adopted. In this case, as a mechanism for managing the transmission power, any of the first and second modes described above can be used alone or in combination. For example, it is not limited to the case where both directions are the first form and the case where both directions are the second form, but the one direction is the first form while the other is the second form. It can also be taken. As a preferable mode, it is preferable that both directions be the second mode.

  In a general communication system, not limited to the present embodiment, a range up to the distance at which the receiving side has the lowest receiving sensitivity level is a receivable region. Therefore, in constructing the signal transmission system 1 in this embodiment, when the transmission chip and the reception chip are one-to-one transmission systems (the first communication system 8_1 side in the configuration of FIG. 1 corresponds), the transmission output level In accordance with one receiving chip, the output level on the transmitting side may be managed in consideration of the minimum receiving sensitivity level.

  On the other hand, in the case of a system configuration in which a plurality of reception chips 2 are arranged for one transmission chip (corresponding to the second communication system 8_2 side in the configuration of FIG. 1), the reception level of each reception chip is set. It is important to consider. In this case, various methods are conceivable as to how to manage the output level of one transmission chip. For example, there are two methods: one that matches the receiver with the highest sensitivity (ignores those that do not reach the minimum receiver sensitivity level: cannot be received) and one that matches the receiver with the lowest receiver sensitivity (ignores excessive ones) It can exist in the opposite direction. In other words, even if “balance” is set on the N receiving sides, a method of adjusting the reception sensitivity to the maximum is adopted in order to enable reception by all the receiving chips 8002 assumed in the system. It is not possible, and the other may become excessive when the reception sensitivity is minimized. It is difficult to think which is optimal, but first set the receiver sensitivity to the minimum so that it can be received by all receiver chips 8002 assumed in the system. It is preferable to perform processing.

  When the mechanism of the signal transmission system of the present embodiment is not applied, a constant baseband is obtained by setting the transmitter output constant at a large level, detecting the signal on the receiving side, and controlling the gain in the receiver. A signal can be obtained. However, between transmission and reception with a short communication distance, communication is at a level larger than necessary, and power consumption is large. Useless power is consumed. Since the receiver needs to be able to receive even a strong input signal, a circuit with good linearity is required, and the power consumption of the receiver increases. When the transmission output is large, there is also a problem that radiation to the outside increases.

  On the other hand, according to the mechanism of the present embodiment, the transmission output level is managed to an appropriate level according to the transmission characteristics between transmission and reception, so that these problems can be solved. In particular, in signal transmission between devices or between devices, signal transmission between fixed positions where the transmission characteristics such as the distance between transmission and reception and the state of the transmission path are specified, or a known positional relationship. The following advantages can be obtained.

  1) It is easy to properly design a propagation channel (waveguide structure) between the transmission side and the reception side.

  2) By designing the dielectric structure of the transmission path coupling unit that seals the transmission side and the reception side and the propagation channel together, good transmission with higher reliability than free space transmission becomes possible.

  3) Control of the controller that manages wireless transmission (in this example, the gain control unit) does not need to be dynamically and frequently performed as in general wireless communication. It can be made smaller than As a result, miniaturization, low power consumption, and high speed can be achieved.

  4) If the wireless transmission characteristics are calibrated at the time of manufacture or design and the individual variations are grasped, the data can be referred to. Therefore, the transmission output level can be set by presetting or static control. Easy.

<First Embodiment>
FIG. 2 is a diagram illustrating a communication system 8A according to the first embodiment to which the signal transmission system 1A according to the first embodiment is applied. FIG. 2 (1) shows a case where transmission / reception is relatively close, and FIG. 2 (2) shows a case where transmission / reception is relatively far. In the first embodiment, the transmission output level is preset based on the communication environment between transmission and reception. Specifically, the transmission output is fixed at a certain level according to the distance between transmission and reception.

  In the case of FIG. 2 (1) where the reception range may be narrow, the transmission output level is set small (low), and in the case of FIG. 2 (2) where the reception range is wide, the transmission output level is set large (high). Once the transmission output level is set based on the communication environment, it is fixed at the set constant level.

  FIG. 3 is a diagram illustrating details of the signal transmission system 1A and the communication system 8A according to the first embodiment. The transmission chip 8001 (TX) and the reception chip 8002 (RX) constitute the basic communication system 8A.

  As shown in FIG. 3A, the transmission chip 8001 is provided with a modulation function unit 8300 and a transmission output amplification unit 8117. Modulation function unit 8300 is an example of a transmission signal processing unit that generates a radio signal based on a baseband signal. If the level of a radio signal to be output is small, power consumption is small, and if the level of a radio signal to be output is large, Power consumption also increases. The transmission output amplification unit 8117 is an example of a variable gain amplification unit (signal adjustment unit) that can adjust the magnitude (amplitude) of a radio signal. Although not shown, a signal processing unit 8012 that generates a baseband signal is provided in front of the modulation function unit 8300 (which may be inside or outside the transmission chip 8001) (see the second embodiment).

  A signal to be transmitted (baseband signal BBin: 12-bit image signal, for example) is converted into a high-speed serial data sequence by a signal generation unit (not shown) and supplied to the modulation function unit 8300. The modulation function unit 8300 modulates the baseband signal as a modulation signal into a millimeter-wave band signal according to a predetermined modulation method.

  For example, the modulation function unit 8300 includes a transmission-side frequency mixing unit (first frequency conversion unit) and a transmission-side local oscillation unit, and multiplies the carrier signal in the millimeter wave band generated by the transmission-side local oscillation unit with a baseband signal. (Modulation) to generate a millimeter-wave band transmission signal (modulated signal, modulated signal) and supply the transmission signal to the transmission output amplifier 8117. The transmission signal is amplified by a variable gain transmission output amplifier 8117 and is radiated from the antenna 8136 as a millimeter-wave band radio signal Sm. The antenna 8136 is an example of a transmission unit that transmits a signal from the transmission output amplification unit 8117, which is an example of a signal adjustment unit, as a radio signal, and is disposed at a predetermined transmission point in the electronic device.

  The reception chip 8002 is provided with a reception amplification unit 8224, a demodulation function unit 8400, and a transmission characteristic index detection unit 8470. The demodulation function unit 8400 is an example of a received signal processing unit that reproduces a baseband signal based on a radio signal. Although not shown, a signal processing unit 8014 that performs signal processing based on the reproduced baseband signal is provided in the subsequent stage of the demodulation function unit 8400 (either inside or outside the transmission chip 8001) (second embodiment). See form).

  Demodulation function unit 8400 is an example of a received signal processing unit that reproduces a baseband signal based on a received radio signal. The demodulation function unit 8400 performs demodulation signal processing on the processed signal (modulated signal) processed by the modulation function unit 8300 to reproduce the baseband signal BBout. The demodulation function unit 8400 can employ various circuit configurations in a range corresponding to the modulation method on the transmission side. For example, the demodulation function unit 8400 includes a reception-side frequency mixing unit (mixer circuit, multiplier) and a reception-side local oscillation unit, and performs signal demodulation from a reception signal received by the antenna 8236 by a so-called synchronous detection method. In the synchronous detection method, a carrier wave is reproduced by a reception side local oscillation unit, and demodulation is performed using the reproduced carrier wave.

  The antenna 8236 is an example of a reception signal unit that receives a radio signal transmitted from the antenna 8136, which is an example of a transmission unit, and is arranged at a predetermined reception point in the electronic device. In the case of intra-device signal transmission and inter-device signal transmission targeted by the present embodiment, the relative positional relationship between the antenna 8136 (that is, the transmission point) and the antenna 8236 (that is, the reception point) may be considered unchanged. A reception signal received by the antenna 8236 is input to a variable gain type and low noise type reception amplifying unit 8224 (LNA), amplitude adjustment is performed, and then supplied to the demodulation function unit 8400. The amplitude-adjusted received signal is input to the frequency mixing unit, and a multiplication signal is generated in the frequency mixing unit by synchronous detection. The multiplication signal generated by the frequency mixing unit generates a waveform (baseband signal) of the input signal sent from the transmission side by removing a high-frequency component by a low-pass filter.

  The transmission characteristic index detection unit 8470 detects the state of transmission characteristics between the transmission chip 8001 (transmission apparatus) and the reception chip 8002 (reception apparatus), and outputs a transmission characteristic index signal based on the detection result. In particular, in this example, it is assumed that the reception level is detected. That is, the transmission characteristic index detection unit 8470 of this example forms a mechanism for detecting the reception level (input level), performs reception level detection, detects the input level, and outputs the level detection signal Vdet as the detection result. Output. Incidentally, the transmission characteristic index detection unit 8470 may be supplied with the input signal of the demodulation function unit 8400 (that is, the received signal, specifically the output of the reception amplification unit 8224), or the base demodulated by the demodulation function unit 8400. A band signal (that is, an output signal of the demodulation function unit 8400) may be supplied. The transmission characteristic index detection unit 8470 detects the input level based on the input signals.

  Detection information (level detection signal Vdet) acquired by the transmission characteristic index detection unit 8470 is referred to when the transmission output level is set by the operator. The operator controls the gain of the transmission output amplifying unit 8117 based on the detection result output from the transmission characteristic index detection unit 8470, so that the transmission output level of the transmission chip 8001 is an appropriate level (just not too low or too high). Adjust to a good level).

  By adopting such a configuration, it is possible to obtain the distance of the transmitter / receiver and the attenuation amount due to the transmission path based on the input level of the receiver indicated by the level detection signal Vdet output from the transmission characteristic index detection unit 8470. The output level of the instrument can be set to an optimum value. When the amount of attenuation is small, it is possible to reduce the output level and perform communication with low power consumption. That is, low power consumption communication can be performed by a transmission chip 8001 (an example of a transmitter) having a transmission output amplification unit 8117 having a variable gain and a reception chip 8002 (an example of a receiver) having a transmission characteristic index detection unit 8470. it can.

  FIG. 3B shows a first configuration example of the transmission output amplifier 8117. The transmission output amplifier 8117 of the first example is an example employing a cascode amplifier circuit in which two NMOSs (Nch MOS transistors) are connected in cascade. The first NMOS 8172 has a grounded source configuration, the source is grounded, the signal Vin is supplied to the gate, and the gain control signal Gcont is supplied via the resistance element 8179. A terminal of the resistance element 8179 opposite to the gate of the NMOS 8172 is a control input terminal of the transmission output amplifier 8117.

  The second NMOS 8174 has a gate ground configuration, a fixed potential (bias voltage Vb) is supplied to the gate, and the source is connected to the drain of the first NMOS 8172. A load circuit 8176 is connected between the drain of the second NMOS 8174 and the power supply Vdd. As the load circuit 8176 of this example, a parallel circuit of an inductor 8177 and a capacitor 8178 is used.

  FIG. 3 (3) shows a second configuration example of the transmission output amplifier 8117. The transmission output amplifying unit 8117 in the second example is an example in which a common source amplifier circuit using one NMOS (Nch type MOS transistor) is employed, and the second NMOS 8174 in the first configuration example is omitted. It has become. A load circuit 8176 (a parallel circuit of an inductor 8177 and a capacitor 8178) is connected between the drain of the first NMOS 8172 and the power supply Vdd.

  The cascode-type first configuration example has a larger number of transistors than the first configuration example, but can provide a large gain. In contrast, the second common source configuration example has a smaller gain than the first configuration example, but the number of large transistors is smaller than that of the first configuration example.

  In any case, the gate voltage (that is, the gain control signal Gcont) of the MOS transistor (first NMOS 8172) is changed to adjust the gain so as to be the minimum necessary transmission output level. The power consumption can be suppressed.

  The gain control signal Gcont employs various methods such as a method of applying a bias from the outside, a method of supplying the control data Dcont to the transmission chip 8001, and generating the gain control signal Gcont in the chip (gain control signal generation unit 8180). be able to. The figure shows the latter example.

  Regardless of whether the first configuration example or the second configuration example is adopted as the transmission output amplifying unit 8117, the transmission output amplifying unit 8117 (variable gain amplifying unit) consumes less power if the level of the output radio signal is small. Thus, the power consumption increases as the level of the output radio signal increases. The mechanism described in Japanese Patent Laid-Open No. 5-347565 is a measure against distortion during short-distance communication, even though the transmission device can control the output level, not for low power consumption. For this reason, since a variable attenuator using a resistor is used for the output section, even if the level of the radio signal to be output is adjusted, the power consumption itself does not change, and the power consumption cannot be reduced. This is different from the mechanism of the present embodiment in which the power consumption can be reduced by setting the level of the radio signal to be output to the necessary minimum level (as small as possible).

Second Embodiment
FIG. 4 is a diagram illustrating a communication system 8B according to the second embodiment to which the signal transmission system 1B according to the second embodiment is applied. Here, FIG. 4 (1) shows an overall outline of the second embodiment, and FIG. 4 (2) shows a detailed configuration example of the second embodiment.

  In the second embodiment, a detection mechanism (transmission characteristic index detection unit) that detects a determination index reflecting actual transmission characteristics is provided on the reception chip 8002 side, and the transmission chip is referred to by referring to the level detection signal Vdet that is the detection result. The transmission output level on the 8001 side is feedback controlled.

  For this reason, the signal transmission system 1B of the second embodiment further includes a gain control unit 8090 that performs feedback control based on the configuration of the first embodiment, as shown in FIG. 4 (1). In the illustrated example, the gain control unit 8090 is provided outside the transmission chip 8001 and the reception chip 8002. Although not shown, the gain control unit 8090 may be incorporated in either the transmission chip 8001 or the reception chip 8002.

  Transmission of the level detection signal Vdet between the transmission characteristic index detection unit 8470 and the gain control unit 8090 and transmission of the level detection signal Vdet between the gain control unit 8090 and the transmission output amplification unit 8117 may be either wireless or wired. In the case of wireless, either light or radio waves may be used, and the frequency band may be the same as or different from the radio signal Sm.

  As shown in FIG. 4 (2), the gain control unit 8090 controls the gain of the transmission output amplification unit 8117 based on the level detection signal Vdet output from the transmission characteristic index detection unit 8470, thereby transmitting the transmission output of the transmission chip 8001. Adjust so that the level is an appropriate level (just a good level that is neither too low nor too high).

  For example, at the beginning of the operation, the transmission chip 8001 (transmission output amplification unit 8117) starts the operation with the maximum output, and the reception chip 8002 (transmission characteristic index detection unit 8470) detects the reception signal level and sends it to the gain control unit 8090. A level detection signal Vdet is supplied. The gain control unit 8090 generates a gain control signal (corresponding to the gain control signal Gcont of the first embodiment) so that the transmission output level becomes an appropriate level based on the level detection signal Vdet, and the transmission output amplification of the transmission chip 8001 The gain of the unit 8117 is controlled. The transmission output amplifying unit 8117 consumes a large amount of power when the transmission output level is high, but can achieve low power consumption by reducing the transmission output level so that the reception level is not too high or too low.

  The gain control unit 8090 performs feedback control of the transmission output level based on the level detection signal Vdet. However, in the case of signal transmission within a device or between devices, once the transmission output level is set, the gain control unit 8090 dynamically and adaptively. It does not need to be done frequently. In order to cope with changes in the communication environment, feedback control may be performed at regular time intervals during communication processing.

<Third Embodiment>
5 to 6 are diagrams illustrating a communication system 8C according to the third embodiment to which the signal transmission system 1C according to the third embodiment is applied. FIG. 5 (1) shows an overall outline of the third embodiment, and FIG. 5 (2) shows a first detailed configuration example of the third embodiment. FIG. 6 shows a second detailed configuration example of the third embodiment.

  As shown in FIG. 5A, the signal transmission system 1C of the third embodiment includes a transmission / reception chip 8003 (TRX1) and a transmission / reception chip 8004 (TRX2), and adopts a configuration corresponding to bidirectional communication.

  The transmission / reception chip 8003 generates a baseband signal and is connected to a signal processing unit 8016 that performs signal processing based on the reproduced baseband signal. The signal processing unit 8016 may be built in the transmission / reception chip 8003. The transmission / reception chip 8004 generates a baseband signal and is connected to a signal processing unit 8018 that performs signal processing based on the reproduced baseband signal. The signal processing unit 8018 may be built in the transmission / reception chip 8004.

  In addition, the signal transmission system 1C according to the third embodiment is configured as the mechanism for managing transmission power in both directions as shown in FIGS. 5 (2) and 6 in the second embodiment. Is adopted. Each functional element of the transmission / reception chip 8003 is given a reference “_1”, and each functional element of the transmission / reception chip 8004 is given a reference “_2”. This reference is omitted when the description is made without distinction.

  In the first detailed configuration example shown in FIG. 5B, the configuration of the second embodiment is applied as it is. In the configuration shown in FIG. 5 (2-1), the functional units for signal transmission in the first communication direction from the transmission / reception chip 8003 to the transmission / reception chip 8004 are a modulation function unit 8300_1, a transmission output amplification unit 8117_1, and a gain control unit. 8090_1, reception amplification unit 8224_2, demodulation function unit 8400_2, and transmission characteristic index detection unit 8470_2. The functional units for signal transmission in the second communication direction from the transmission / reception chip 8004 to the transmission / reception chip 8003 include a modulation function unit 8300_2, a transmission output amplification unit 8117_2, a gain control unit 8090_2, a reception amplification unit 8224_1, a demodulation function unit 8400_1, This is a transmission characteristic index detection unit 8470_1.

  In the configuration shown in FIG. 5 (2-2), the functional units for signal transmission in the first communication direction from the transmission / reception chip 8003 to the transmission / reception chip 8004 are a modulation function unit 8300_1, a transmission output amplification unit 8117_1, and a gain control unit. 8090_2, reception amplification unit 8224_2, demodulation function unit 8400_2, and transmission characteristic index detection unit 8470_2. The functional units for signal transmission in the second communication direction from the transmission / reception chip 8004 to the transmission / reception chip 8003 include a modulation function unit 8300_2, a transmission output amplification unit 8117_2, a gain control unit 8090_1, a reception amplification unit 8224_1, a demodulation function unit 8400_1, This is a transmission characteristic index detection unit 8470_1.

  Although not shown, the gain control unit 8090_1 and the gain control unit 8090_2 may be arranged outside the transmission / reception chips 8003 and 8004. In this case, one gain control unit 8090 having both functions may be provided. Below, it demonstrates with the structure shown to FIG. 5 (2-1).

  The transmission / reception chip 8003 performs modulation processing based on the first baseband signal BBin1, and supplies the modulated first radio signal Sm1 to the transmission / reception chip 8004. The transmission / reception chip 8004 performs modulation processing based on the second baseband signal BBin2, and supplies the modulated second radio signal Sm2 to the transmission / reception chip 8003.

  The transmission / reception chip 8003 is supplied with the first level detection signal Vdet1 from the transmission / reception chip 8004, and the transmission / reception chip 8004 is supplied with the second level detection signal Vdet2. The transmission / reception chip 8003 controls the transmission output level of the first radio signal Sm1 to be an appropriate level based on the first level detection signal Vdet1. The transmission / reception chip 8004 controls the transmission output level of the second radio signal Sm2 to be an appropriate level based on the second level detection signal Vdet2.

  The transmission of the level detection signal Vdet_1 between the transmission characteristic index detection unit 8470_1 and the gain control unit 8090_2 and the transmission of the level detection signal Vdet_2 between the transmission characteristic index detection unit 8470_1 and the gain control unit 8090_2 may be either wireless or wired. In the case of wireless, either light or radio waves may be used, and the frequency band may be the same as or different from the radio signals Sm1 and Sm2.

  In the second detailed configuration example shown in FIG. 6, some modifications are added to the first detailed configuration example. Specifically, in the second detailed configuration example, each of the transmission / reception chip 8003 and the transmission / reception chip 8004 includes a 2-input / 1-output type signal selection unit 8472 (selector) on the input side of the modulation function unit 8300. .

  The signal selection unit 8472 is supplied with the baseband signal BBin at one input terminal and the output level control data Ddet acquired by the transmission characteristic index detection unit 8470 at the other input terminal. The output level control data Ddet is obtained by encoding the level detection signal Vdet.

  A signal is supplied from the demodulation function unit 8400 to the gain control unit 8090 and the transmission characteristic index detection unit 8470 in common.

  When the communication direction is information communication from the transmission / reception chip 8003 to the transmission / reception chip 8004 (first communication direction), the signal selection unit 8472_1 selects the first baseband signal BBin1, and the signal selection unit 8472_2 has a transmission characteristic index detection unit. The first output level control data Ddet1 output from 8470_2 is selected. The transmission / reception chip 8003 performs modulation processing based on the first baseband signal BBin1, and supplies the modulated first radio signal Sm1 to the transmission / reception chip 8004. The transmission characteristic index detector 8470_2 detects the reception level at this time and outputs the output level control data Ddet1. The signal selection unit 8472_2 selects the output level control data Ddet1 and supplies it to the modulation function unit 8300_2. As a result, the modulated radio signal Sm2 for the output level control data Ddet1 is supplied to the demodulation function unit 8400_1 of the transmission / reception chip 8003. The demodulation function unit 8400_1 regenerates the output level control data Ddet1 by demodulating the radio signal Sm2, and supplies it to the gain control unit 8090_1. The gain controller 8090_1 generates the first gain control signal Gcont1 based on the demodulated output level control data Ddet1, and supplies the first gain control signal Gcont1 to the control input terminal of the transmission output amplifier 8117_1. Control is performed so that the transmission output level of the first radio signal Sm1 becomes an appropriate level.

  When the communication direction is information communication from the transmission / reception chip 8004 to the transmission / reception chip 8003 (second communication direction), the signal selection unit 8472_2 selects the second baseband signal BBin2, and the signal selection unit 8472_1 is a transmission characteristic index detection unit. The second output level control data Ddet2 output from 8470_1 is selected. The transmission / reception chip 8004 performs modulation processing based on the second baseband signal BBin2, and supplies the modulated second radio signal Sm2 to the transmission / reception chip 8003. The transmission characteristic index detection unit 8470_1 detects the reception level at this time and outputs the output level control data Ddet2. The signal selection unit 8472_1 selects the output level control data Ddet2 and supplies it to the modulation function unit 8300_1. As a result, the modulated radio signal Sm1 for the output level control data Ddet2 is supplied to the demodulation function unit 8400_2 of the transmission / reception chip 8004. The demodulation function unit 8400_2 demodulates the radio signal Sm1 to reproduce the output level control data Ddet2, and supplies it to the gain control unit 8090_2. The gain controller 8090_2 generates a second gain control signal Gcont2 based on the demodulated output level control data Ddet2, and supplies the second gain control signal Gcont2 to the control input terminal of the transmission output amplifier 8117_2. Control is performed so that the transmission output level of the second radio signal Sm2 becomes an appropriate level.

  In any of the first detailed configuration example and the second detailed configuration example, when the bidirectional communication system is realized, each received signal level is detected, output level control data is transmitted to the other party, and the output level As a result, the output amplifier can be operated with low power consumption to realize low power consumption communication.

  Incidentally, the second detailed configuration example is limited to application to two-way communication in time division, whereas the first detailed configuration example has no such restriction. In the second detailed configuration example, since the radio signal for the level detection signal Vdet is transmitted by using the signal transmission path for the radio signal Sm in the idle time of normal signal transmission, it is more than that in the first detailed configuration example. The transmission path can be reduced. That is, in the second detailed configuration example, a dedicated transmission line is not required for the level detection signal Vdet.

<Application examples to electronic devices>
[First example]
FIG. 7 is a diagram illustrating a first example of an electronic device to which the mechanism of the signal transmission system 1 of the present embodiment is applied. The first example is an application example in the case where signal transmission is performed wirelessly within the casing of one electronic device. As an electronic device, an example of application to an imaging device equipped with a solid-state imaging device will be described. This type of imaging apparatus is distributed in the market as, for example, a digital camera, a video camera (camcorder), or a camera of a computer device (Web camera).

  A first communication device (corresponding to the communication device 2) is mounted on a main board on which a control circuit, an image processing circuit, and the like are mounted, and a second communication device (corresponding to the communication device 2) is mounted on an imaging substrate (camera) System configuration mounted on the board). In the following description, it is assumed that data is wirelessly transmitted in the millimeter wave band.

  An imaging board 502 and a main board 602 are disposed in the housing 590 of the imaging apparatus 500. A solid-state imaging device 505 is mounted on the imaging substrate 502. For example, the solid-state imaging device 505 is a CCD (Charge Coupled Device), and the case where it is mounted on the imaging substrate 502 including its drive unit (horizontal driver or vertical driver) or a CMOS (Complementary Metal-oxide Semiconductor) sensor is applicable. To do.

  A semiconductor chip 103 that functions as a first communication device is mounted on the main substrate 602, and a semiconductor chip 203 that functions as a second communication device is mounted on the imaging substrate 502. Although not shown, peripheral circuits such as an imaging drive unit are mounted on the imaging substrate 502 in addition to the solid-state imaging device 505, and an image processing engine, an operation unit, various sensors, and the like are mounted on the main substrate 602.

  In each of the semiconductor chip 103 and the semiconductor chip 203, functions equivalent to those of the transmission chip 8001 and the reception chip 8002 are incorporated. By incorporating both functions of the transmission chip 8001 and the reception chip 8002 or by incorporating the functions of the transmission / reception chips 8003 and 8004, bidirectional communication can be dealt with. These points are the same in other application examples described later.

  The solid-state imaging device 505 and the imaging drive unit correspond to an application function unit (which generates a baseband signal or processes a reproduced baseband signal) of the LSI function unit on the first communication device side. The LSI function unit is connected to a signal generator on the transmission side, and is further connected to the antenna 236 via a transmission line coupling unit. The signal generation unit and the transmission path coupling unit are accommodated in a semiconductor chip 203 different from the solid-state imaging device 505 and are mounted on the imaging substrate 502.

  The image processing engine, the operation unit, and various sensors correspond to the application function unit of the LSI function unit on the second communication device side (for generating a baseband signal or processing the reproduced baseband signal). An image processing unit that processes an imaging signal obtained by the solid-state imaging device 505 is accommodated. The LSI function unit is connected to a signal generation unit on the reception side, and is further connected to the antenna 136 via a transmission line coupling unit. The signal generation unit and the transmission path coupling unit are accommodated in a semiconductor chip 103 different from the image processing engine and are mounted on the main substrate 602.

  The transmission-side signal generation unit includes, for example, a multiplexing processing unit, a parallel-serial conversion unit, a modulation unit, a frequency conversion unit, and an amplification unit, and the reception-side signal generation unit includes, for example, an amplification unit, a frequency conversion unit, and a demodulation unit Unit, serial / parallel conversion unit, unification processing unit, and the like. These points are the same in other application examples described later.

  By performing wireless communication between the antenna 136 and the antenna 236, an image signal acquired by the solid-state imaging device 505 is transmitted to the main board 602 via the wireless signal transmission path 9 between the antennas. In this case, for example, a reference clock for controlling the solid-state imaging device 505 and various control signals are transmitted via the wireless signal transmission path 9 between the antennas to the imaging substrate 502. Is transmitted to.

  7 (1) and (2), two high-frequency signal transmission paths 9 are provided. In FIG. 7 (1), the free space transmission line 9B is used as the radio signal transmission line 9, and the system of the carrier frequency f1 (free space transmission line 9B_1) and the system of the carrier frequency f2 (free space transmission line 9B_2) are The frequency is separated to the extent that interference does not occur. In FIG. 7 (2), a hollow waveguide 9L having a structure surrounded by a shielding material MZ and having a hollow inside is used as the radio signal transmission path 9, and a system (free space transmission path 9B_1) of the carrier frequency f1 is used. The system of the carrier frequency f2 (free space transmission line 9B_2) prevents interference from occurring even if the frequency is the same.

  The imaging board 502 and the main board 602 are fixed at predetermined positions in the housing 590. Therefore, the positional relationship between the semiconductor chips 103 and 203 and the antennas 136 and 236 on each substrate is also fixed at a predetermined position. In signal transmission in the imaging device 505, which is an example of an electronic device, transmission characteristics such as a distance between transmission and reception and a state of a transmission path are specified. Therefore, a propagation channel between a transmission side and a reception side is appropriately set. Easy to design. The transmission characteristics in the housing 590 are calibrated at the time of manufacture or design, the variation of individual semiconductor chips 103, 203, etc. is grasped, and the data is referred to. It will be better with general control. Even when feedback control is performed based on the level detection signal Vdet acquired by the transmission characteristic index detection unit 8470, it is not necessary to frequently and dynamically perform setting control. Power consumption and speed can be increased.

[Second example]
FIG. 8 is a diagram illustrating a second example of an electronic device to which the mechanism of the present embodiment is applied. The second example is an application example in the case where signal transmission is performed wirelessly between electronic devices in a state where a plurality of electronic devices are integrated. In particular, the present invention is applied to signal transmission between both electronic devices when one electronic device is mounted on the other electronic device. In the following description, it is assumed that the multiplied reference signal J1 is wirelessly transmitted in the millimeter wave band and data is wirelessly transmitted in the millimeter wave band.

  For example, a so-called IC card or memory card with a built-in central processing unit (CPU) or non-volatile storage device (for example, flash memory) is installed in the main body side electronic equipment. Some are made possible (detachable). A card type information processing apparatus which is an example of one (first) electronic device is also referred to as a “card type apparatus” below. The other (second) electronic device on the main body side is also simply referred to as an electronic device below.

  A structural example (planar perspective and sectional perspective) of the memory card 201B is shown in FIG. An example of the structure (planar perspective and sectional perspective) of the electronic device 101B is shown in FIG. FIG. 8 (3) shows a structural example (cross-sectional perspective view) when the memory card 201B is inserted into the slot structure 4 (particularly the opening 192) of the electronic apparatus 101B.

  The slot structure 4 is configured such that the memory card 201B (the casing 290) can be inserted into and removed from the housing 190 of the electronic apparatus 101B from the opening 192. A receiving-side connector 180 is provided at a contact position with the terminal of the memory card 201B of the slot structure 4. Connector terminals (connector pins) are not required for signals replaced with wireless transmission.

  As shown in FIG. 8 (1), a cylindrical concave configuration 298 (depression) is provided in the housing 290 of the memory card 201B, and as shown in FIG. 8 (2), a cylindrical projection is formed on the housing 190 of the electronic apparatus 101B. A shape configuration 198 (protrusion) is provided. The memory card 201 </ b> B has a semiconductor chip 203 on one surface of the substrate 202, and an antenna 236 is formed on one surface of the substrate 202. The housing 290 has a concave configuration 298 formed on the same surface as the antenna 236, and a portion of the concave configuration 298 is formed of a dielectric resin including a dielectric material capable of transmitting a radio signal.

  On one side of the substrate 202, a connection terminal 280 for connecting to the electronic device 101 </ b> B at a predetermined position of the housing 290 is provided at a predetermined position. The memory card 201B partially includes a conventional terminal structure for low-speed, small-capacity signals and power supply. What can be a target of millimeter wave signal transmission has terminals removed as indicated by broken lines in the figure.

  As illustrated in FIG. 8B, the electronic device 101 </ b> B includes the semiconductor chip 103 on the surface on the opening 192 side of the substrate 102, and the antenna 136 is formed on one surface of the substrate 102. The housing 190 has an opening 192 in which the memory card 201B is inserted and removed as the slot structure 4. When the memory card 201B is inserted into the opening 192, a convex configuration 198 having a millimeter-wave confinement structure (waveguide structure) is formed on the housing 190 at a portion corresponding to the position of the concave configuration 298. It is configured to be a body transmission line 9A.

  As shown in FIG. 8 (3), the housing 190 of the slot structure 4 has a convex configuration 198 (dielectric transmission line 9A) and a concave configuration 298 that are concave and convex with respect to the insertion of the memory card 201B from the opening 192. It has a mechanical structure that makes contact. When the concavo-convex structure is fitted, the antenna 136 and the antenna 236 face each other, and the dielectric transmission path 9 </ b> A is disposed as the radio signal transmission path 9 therebetween. The memory card 201B sandwiches the housing 290 between the dielectric transmission path 9A and the antenna 236, but since the material of the concave configuration 298 is a dielectric material, it greatly affects wireless transmission in the millimeter wave band. It is not a thing.

  When the memory card 201B is attached to the fitting structure of the electronic device 101B, since both are fixed at a predetermined position, the positional relationship between the semiconductor chips 103 and 203 and the antennas 136 and 236 is also fixed at a predetermined position. The In the signal transmission between the devices of the memory card 201B and the electronic device 101B, which is an example of the electronic device, the transmission characteristics such as the distance between transmission and reception and the state of the transmission path are specified. Action and effect are obtained.

[Third example]
FIG. 9 is a diagram illustrating a third example of an electronic device to which the mechanism of the present embodiment is applied. The signal transmission system 1 includes a portable image reproduction device 201K as an example of a first electronic device, and an image acquisition device 101K as an example of a second (main body side) electronic device on which the image reproduction device 201K is mounted. I have. In the image acquisition apparatus 101K, a mounting table 5K on which the image reproduction apparatus 201K is mounted is provided in a part of the housing 190. Instead of the mounting table 5K, the slot structure 4 may be used as in the second example. This is the same as the second example in that signal transmission is performed wirelessly between both electronic devices when one electronic device is attached to the other electronic device. Below, it demonstrates paying attention to difference with a 2nd example.

  The image acquisition device 101K has a substantially rectangular parallelepiped (box shape) shape and is no longer a card type. The image acquisition device 101K may be any device that acquires moving image data, for example, and corresponds to, for example, a digital recording / reproducing device or a terrestrial television receiver. The image reproduction device 201K has, as an application function unit, a storage device that stores moving image data transmitted from the image acquisition device 101K side, or a moving image data read from the storage device and a display unit (for example, a liquid crystal display device or an organic EL display). A function unit for reproducing a moving image is provided in the apparatus. Structurally, it may be considered that the memory card 201B is replaced with the image reproducing device 201K and the electronic apparatus 101B is replaced with the image acquiring device 101K.

  In the casing 190 below the mounting table 5K, for example, as in the second example (FIG. 8), the semiconductor chip 103 is accommodated, and an antenna 136 is provided at a certain position. A dielectric transmission path 9 </ b> A is made of a dielectric material as a radio signal transmission path 9 in a portion of the housing 190 that faces the antenna 136. In the housing 290 of the image reproducing device 201K mounted on the mounting table 5K, for example, as in the second example (FIG. 8), the semiconductor chip 203 is accommodated, and an antenna 236 is provided at a certain position. . The portion of the housing 290 that faces the antenna 236 is configured such that the radio signal transmission path 9 (dielectric transmission path 9A) is made of a dielectric material. These points are the same as in the second example.

  The third example adopts a wall surface abutting method instead of the concept of a fitting structure, and the antenna 136 and the antenna 236 face each other when the image acquisition device 101K is placed against the corner 101a of the mounting table 5K. Therefore, it is possible to reliably eliminate the influence of positional misalignment. With such a configuration, when the image reproducing device 201K is mounted (mounted) on the mounting table 5K, it is possible to perform alignment with respect to the wireless signal transmission of the image reproducing device 201K. Although the housing 190 and the housing 290 are sandwiched between the antenna 136 and the antenna 236, since it is a dielectric material, it does not greatly affect wireless transmission in the millimeter wave band.

  When the image reproduction device 201K is mounted on the mounting table 5K of the image acquisition device 101K, both are fixed at a predetermined position, so that the positional relationship between the semiconductor chips 103 and 203 and the antennas 136 and 236 is also determined. Fixed. In the signal transmission between the devices of the image reproducing device 201K and the image acquisition device 101K which is an example of the electronic device, the transmission characteristics such as the distance between transmission and reception and the state of the transmission path are specified. The same operation and effect as the second example can be obtained.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. Various changes or improvements can be added to the above-described embodiment without departing from the gist of the invention, and embodiments to which such changes or improvements are added are also included in the technical scope of the present invention.

  Further, the above embodiments do not limit the invention according to the claims (claims), and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. Absent. The embodiments described above include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. Even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, as long as an effect is obtained, a configuration from which these some constituent requirements are deleted can be extracted as an invention.

  For example, in the above-described embodiment, the example in which the received signal or the level of the baseband signal is used as the determination index in setting the amplitude level of the transmission signal has been described, but this is only an example. For example, in a system using an IF (intermediate frequency) signal, the level of the IF signal can be used as a determination index value. FIG. 10 shows a configuration example in that case. It is almost the same as other examples just by detecting the level with the IF signal. That is, in the case of a system using an IF signal, the IF signal level may be detected and the transmission output level may be set.

  DESCRIPTION OF SYMBOLS 1 ... Signal transmission system, 2 ... Communication apparatus, 8 ... Communication system, 8000 ... Communication chip, 8001 ... Transmission chip, 8002 ... Reception chip, 8003, 8004 ... Transmission / reception chip, 8012-8018 ... Signal processing part, 8090 ... Gain control 8117 ... Transmission output amplification unit 8136 8236 ... Antenna 8224 ... Reception amplification unit 8300 ... Modulation function unit 8400 ... Demodulation function unit 8470 ... Transmission characteristic index detection unit 8472 ... Signal selection unit

Claims (20)

A signal adjustment unit for adjusting and outputting the magnitude of the input signal;
A transmission unit that is disposed at a predetermined transmission location in the electronic device and transmits a signal output from the signal adjustment unit as a radio signal;
A receiving unit that is disposed at a predetermined reception location in the electronic device, and that receives a radio signal transmitted from the transmitting unit;
With
In the signal adjustment unit, a size of a radio signal transmitted from the transmission unit to the reception unit is set according to transmission characteristics between the transmission unit and the reception unit. There are a plurality of transmission channels composed of the transmitting unit and at least one receiving unit,
The signal transmission system according to claim 1, wherein when the characteristics of the respective transmission channels are different, the sizes of the radio signals transmitted from the transmission units of the respective transmission channels are different. 3. The signal adjustment unit sets the magnitude of a radio signal transmitted from the transmission unit to a minimum level necessary for communication between the transmission unit and the reception unit. The signal transmission system described in 1. The transmission characteristic index detection part which detects the state of the transmission characteristic between the said transmission part and the said receiving part, and outputs a transmission characteristic parameter | index signal based on a detection result is provided. The signal transmission system according to item. A reception signal processing unit that performs signal processing based on the signal received by the reception unit;
The signal transmission system according to claim 4, wherein the transmission characteristic index detection unit detects an input level of a signal input to the reception signal processing unit as the state of the transmission characteristic. A gain control unit that controls the magnitude of a radio signal transmitted from the transmission unit by controlling the signal adjustment unit based on a transmission characteristic index signal output from the transmission characteristic index detection unit. Item 6. The signal transmission system according to Item 4 or Item 5. The signal transmission system according to claim 6, further comprising a function unit configured to transmit the transmission characteristic index signal output from the transmission characteristic index detection unit as a wireless signal. The transmission unit and the reception unit are provided in two sets capable of bidirectional communication,
The signal transmission system according to claim 6, wherein the transmission characteristic index detection unit and the gain control unit are provided for each communication direction. A first transmission signal processing unit that performs signal processing based on a baseband signal and supplies the processed signal as an input signal to the signal adjustment unit; a first signal selection unit that selects one of a plurality of signals; A first received signal processing unit that performs signal processing based on a signal received by the receiving unit with respect to the first communication direction;
A second transmission signal processing unit that performs signal processing based on a baseband signal and supplies the processed signal as an input signal to the signal adjustment unit; a second signal selection unit that selects one of a plurality of signals; A second received signal processing unit that performs signal processing based on a signal received by the receiving unit with respect to a second communication direction opposite to the first communication direction;
When performing signal transmission in the first communication direction, the first signal selection unit selects the baseband signal and inputs it to the first transmission signal processing unit, and the second signal selection unit The transmission characteristic indicator signal output from the transmission characteristic indicator detector for the first communication direction is selected and input to the second transmission signal processor, and the second transmission signal processor is the second transmission signal processor. The transmission characteristic index signal input from the signal selection unit is converted into a radio signal, and the second reception signal processing unit for the second communication direction receives the radio signal of the transmission characteristic index signal and converts the transmission characteristic index signal to Play and input to the first gain controller for the first communication direction,
When performing signal transmission in the second communication direction, the second signal selection unit selects the baseband signal and inputs it to the second transmission signal processing unit, and the first signal selection unit The transmission characteristic indicator signal output from the transmission characteristic indicator detector for the second communication direction is selected and input to the first transmission signal processor, and the first transmission signal processor is the first transmission signal processor. The transmission characteristic index signal input from the signal selection unit is converted into a radio signal, and the first reception signal processing unit for the first communication direction receives the radio signal of the transmission characteristic index signal and converts the transmission characteristic index signal into the transmission characteristic index signal. The signal transmission system according to claim 8, wherein the signal is reproduced and input to the second gain control unit for the second communication direction. The transmitting unit and the receiving unit are housed in a casing of the same electronic device, and a wireless signal transmission path that enables wireless signal transmission between the transmitting unit and the receiving unit is formed in the casing. The signal transmission system according to any one of claims 1 to 9. The transmission unit is housed in the housing of the first electronic device, the receiving unit is housed in the housing of the second electronic device, and the first electronic device and the second electronic device are defined. 10. The signal according to claim 1, wherein a wireless signal transmission path that enables wireless signal transmission is formed between the transmission unit and the reception unit when integrated with each other. 11. Transmission system. A signal adjustment unit for adjusting and outputting the magnitude of the input signal;
A transmission unit that is disposed at a predetermined transmission location in the electronic device, and that transmits the signal output from the signal adjustment unit to the reception unit as a radio signal;
With
In the signal adjustment unit, a size of a radio signal transmitted from the transmission unit is set according to a transmission characteristic between the transmission unit and the reception unit. The signal adjustment unit based on the transmission characteristic index signal output from the transmission characteristic index detection unit that detects the state of the transmission characteristic between the transmission unit and the reception unit and outputs a transmission characteristic index signal based on the detection result The communication apparatus according to claim 12, further comprising: a gain control unit that controls a magnitude of a radio signal transmitted from the transmission unit by controlling the frequency. A receiver for receiving a radio signal;
A transmission characteristic indicator detector that detects a state of transmission characteristics between the transmitter and the receiver, and outputs a transmission characteristic indicator signal based on the detection result;
A communication device comprising: The communication apparatus according to claim 14, further comprising: a gain control unit that controls a magnitude of a radio signal transmitted from the transmission unit based on a transmission characteristic index signal output from the transmission characteristic index detection unit. A signal adjustment unit for adjusting and outputting the magnitude of the input signal;
A transmission unit that is disposed at a predetermined transmission location in the electronic device and transmits a signal output from the signal adjustment unit as a radio signal;
A receiving unit that is disposed at a predetermined reception location in the electronic device, and that receives a radio signal transmitted from the transmitting unit;
With
In the signal adjustment unit, a size of a radio signal transmitted from the transmission unit to the reception unit is set according to a transmission characteristic between the transmission unit and the reception unit. The communication apparatus according to claim 16, further comprising: a gain control unit that controls a magnitude of a radio signal transmitted from the transmission unit based on a transmission characteristic index signal output from the transmission characteristic index detection unit. A signal adjustment unit for adjusting and outputting the magnitude of the input signal;
A transmission unit that is arranged at a predetermined transmission location, and that transmits a signal output from the signal adjustment unit to the reception unit as a radio signal;
With
The electronic device in which the magnitude of a radio signal transmitted from the transmission unit to the reception unit is set in the signal adjustment unit in accordance with transmission characteristics between the transmission unit and the reception unit. A receiving unit that is arranged at a predetermined receiving location and receives a radio signal transmitted from the transmitting unit;
A transmission characteristic index detection unit that detects a state of transmission characteristics between the transmission unit and the reception unit and outputs a transmission characteristic index signal based on a detection result;
Equipped with electronic equipment. Place the transmitter and receiver at a predetermined location in the electronic device,
In the signal adjustment unit, according to the transmission characteristics between the transmission unit and the reception unit, set the magnitude of the radio signal transmitted from the transmission unit to the reception unit,
A signal transmission method of transmitting a signal output from a signal adjustment unit as a radio signal from the transmission unit to the reception unit.

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