CN111399009A - Multimode navigation receiving device - Google Patents

Abstract

The invention discloses a multimode navigation receiving device, and relates to the navigation receiving technology. The scheme is provided aiming at the problem that a plurality of phase-locked loops interfere with each other or the integrated volume is large in the prior art. A phase-locked loop divides local oscillator signals with different frequencies through two different frequency dividers for use by two receiving channels. The structure is simple, and multimode frequency receiving can be realized under the configuration of one antenna, one phase-locked loop and two independent receiving channels. Compared with the prior art, the volume of the multimode navigation receiving device is obviously reduced, and the problem of mutual interference of phase-locked loop signals is completely avoided.

Description

A multi-mode navigation receiver

technical field

The present invention relates to a navigation receiving technology, in particular to a multi-mode navigation receiving device.

Background technique

With the construction and continuous improvement of global navigation satellite systems (GNSS) such as GPS (Global Positioning System) in the United States, GLONASS (GLONASS) in Russia, Galileo (Galileo) in Europe and Beidou (BDS) in China, as well as navigation and positioning The demand for precision is getting higher and higher. More and more terminal devices are required to be able to receive GPS, GLONASS, Galileo and Beidou and other multi-frequency GNSS signals at the same time to achieve higher-precision positioning.

However, the signals of the global navigation satellite system are mainly distributed between 1165MHz-1280MHz and 1560MHz-1620MHz. As shown in the table:

model RF Frequency (MHz) Bandwidth (MHz) GPS L5 1176.45 20.46 Galileo E5a 1176.45 20.46 Glonass L3 1202.025 20.46 BDS B2 1207.14 20.46 Galileo E5b 1207.14 20.46 GPS L2 1227.6 20.46 Glonass L2 1246 6.7 BDS B3 1268.52 20.46 BDS B1 1561.098 4.092 GPS L1 1575.42 2.046 Galileo E1 1575.42 4.092 Glonass L1 1602 8.3

Usually these navigation signals are received by more than three single-channel receiver chips, or received by a chip that integrates more than three independent receiving channels. When using more than three single-channel receiving chips to receive, the device is bulky. However, when more than three independent receiving channels are integrated on the same chip, the chip integrates multiple phase-locked loops and brings about mutual interference of clocks. How to reduce the number of receiving channels, avoid mutual interference between multiple PLLs, and also realize multi-mode frequency reception is a technical problem to be solved urgently in the art.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems in the prior art, the present invention aims to provide a multi-mode navigation receiving device.

A multi-mode navigation receiving device according to the present invention comprises: an antenna, a low noise amplifier, a phase locked loop, a first frequency divider, a second frequency divider, a first receiving channel and a second receiving channel;

The radio frequency signal of the antenna is divided into two signals after passing through the low noise amplifier, one signal is processed by the first receiving channel and then output, and the other signal is processed by the second receiving channel and then output;

The output frequency of the phase-locked loop is respectively input to the first frequency divider and the second frequency divider; the first frequency divider outputs two quadrature local oscillator signals to the first receiving channel, and the second frequency divider The device outputs two other quadrature local oscillator signals to the second receiving channel.

The multi-mode navigation receiving device of the present invention has the advantages of simple structure, and can realize multi-mode frequency reception under the configuration of one antenna, one phase-locked loop and two independent receiving channels. Compared with the existing ones, the volume of the multi-mode navigation receiving device is obviously reduced, and the problem of mutual interference of phase-locked loop signals is completely avoided.

The first receiving channel and the second receiving channel have the same structure: they respectively include an I-channel mixer, a Q-channel mixer, two filters, two programmable amplifiers, and two analog-to-digital converters; the I-channel mixer The input end is connected to the low noise amplifier, and the output end passes through a filter, a programmable amplifier and an analog-to-digital converter in sequence; the input end of the Q-channel mixer is connected to the low noise amplifier, and the output end passes through in sequence Another filter, another programmable amplifier and another output after the analog-to-digital converter;

The first frequency divider outputs the quadrature I-channel local oscillator signal and the Q-channel local oscillator signal; the second frequency divider outputs another I-channel local oscillator signal and another Q-channel local oscillator signal that are orthogonal;

The I-channel local oscillator signal of the first frequency divider is input to the I-channel mixer of the first receiving channel, and the Q-channel local oscillator signal is input to the Q-channel mixer of the first receiving channel;

The I-channel local oscillator signal of the second frequency divider is input to the I-channel mixer of the second receiving channel, and the Q-channel local oscillator signal is input to the Q-channel mixer of the second receiving channel. The purpose is to provide a specific implementation manner and connection structure.

The output frequency of the phase-locked loop is f _VCO , the frequency dividing ratio of the first frequency divider is 1:N1, and the frequency dividing ratio of the second frequency divider is 1:N2; and the following relationship is satisfied: 1165MHz≤f _VCO / N1≤1280MHz, 1560MHz≤f _VCO /N2≤1620MHz. Provides the best proportional relationship.

The output frequency of the phase-locked loop is f _VCO =9720MHz, the frequency division ratio of the first frequency divider is 1:8, and the frequency division ratio of the second frequency divider is 1:6. Preferred values are provided in the optimal ratio relationship.

The low noise amplifier, the phase locked loop, the first frequency divider, the second frequency divider, the first receiving channel and the second receiving channel are integrated in the same chip. The purpose is to provide a technical solution with a higher degree of integration.

Description of drawings

FIG. 1 is a schematic structural diagram of the multi-mode navigation receiving device according to the present invention.

Reference number:

ANT-antenna;

U1-chip, LNA-low noise amplifier, RX1-first receiving channel, RX2-second receiving channel;

RFIN_RX-radio frequency input terminal, OUT_RX1-output terminal group of the first receiving channel, OUT_RX2-output terminal group of the second receiving channel;

Mixer_I-I mixer, Mixer_Q-Q mixer, Filter-filter, PGA-programmable amplifier, ADC-analog-to-digital converter;

PLL-phase locked loop, /N1-first frequency divider, /N2-second frequency divider;

Flo1_I-I local oscillator signal of the first frequency divider, Flo1_Q-Q local oscillator signal of the first frequency divider;

Flo2_I-channel I local oscillator signal of the second frequency divider, Flo2_Q-channel Q local oscillator signal of the second frequency divider.

Detailed ways

As shown in FIG. 1, a multi-mode navigation receiving device according to the present invention at least includes an antenna ANT, a low noise amplifier LNA, a first receiving channel RX1, a second receiving channel RX2, a phase-locked loop PLL, a first receiving channel RX1, and a first receiving channel RX2. divider and second divider. The low-noise amplifier, the phase-locked loop, the first frequency divider, the second frequency divider, the first receiving channel and the second receiving channel are integrated in the same chip U1. The chip is provided with a radio frequency input terminal RFIN_RX for connecting to the antenna, an output terminal group OUT_RX1 of the first receiving channel and an output terminal group OUT_RX2 of the second receiving channel for connecting to the receiving baseband of the subsequent stage.

The first receiving channel and the second receiving channel have the same structure, including an I-channel mixer, a Q-channel mixer, and two filters, two programmable amplifiers, and two analog-to-digital converters set as required. The input end of the I-channel mixer is connected to the low-noise amplifier, and the output end passes through a filter, a programmable amplifier and an analog-to-digital converter in sequence and outputs. The input end of the Q-channel mixer is connected to the low-noise amplifier, and the output end passes through another filter, another programmable amplifier and another analog-to-digital converter in sequence and outputs.

The first frequency divider outputs quadrature I-channel local oscillator signal Flo1_I and Q-channel local oscillator signal Flo1_Q; the second frequency divider outputs another I-channel local oscillator signal Flo2_I and another Q-channel local oscillator signal Flo2_Q in quadrature. The I-channel local oscillator signal Flo1_I of the first frequency divider is input to the I-channel mixer of the first receiving channel, and the Q-channel local oscillator signal Flo1_Q is input to the Q-channel mixer of the first receiving channel. The I-channel local oscillator signal Flo2_I of the second frequency divider is input to the I-channel mixer of the second receiving channel, and the Q-channel local oscillator signal Flo2_Q is input to the Q-channel mixer of the second receiving channel.

In order to realize that the two receiving channels process a frequency range respectively, the output frequency of the phase-locked loop is f _VCO , the frequency dividing ratio of the first frequency divider is 1:N1, and the frequency dividing ratio of the second frequency divider is 1: N2. The following relationships are satisfied: 1165MHz≤f _VCO /N1≤1280MHz, 1560MHz≤f _VCO /N2≤1620MHz. Under this ratio, the first receiving channel can process the navigation signal from 1165MHz to 1280MHz, and the second receiving channel can process the navigation signal from 1560MHz to 1620MHz.

And provide preferred values, the output frequency of the phase locked loop is f _VCO =9720MHz, the frequency division ratio of the first frequency divider is 1:8, and the frequency division ratio of the second frequency divider is 1:6. That is, the output frequency of the first frequency divider is 1215MHz, and the output frequency of the second frequency divider is 1620MHz. The receiving configuration corresponding to the global navigation signal is shown in the following table:

The working principle of the multi-mode navigation receiving device of the present invention is as follows: the antenna receives the navigation signal, and according to the different frequency division results, the first receiving channel is responsible for processing the navigation signal from 1165MHz to 1280MHz, and the second receiving channel is responsible for processing the navigation signal from 1560MHz to 1620MHz. Signal. Each receiving channel is down-converted by two mixers, I and Q, to output an analog IF signal. The I and Q analog IF signals are filtered by filters to filter out out-of-band interference signals and noise. Then it is amplified to the amplitude required by the analog-to-digital converter through a programmable amplifier. Finally, two analog-to-digital converters output I and Q digital signals to the baseband outside the chip for processing.

According to a preferred configuration, the intermediate frequency of the first receiving channel is -48.78MHz to +63.75MHz, and the intermediate frequency of the second receiving channel is -60.948MHz to -13.85MHz. The bandwidth of the filter, programmable amplifier and analog-to-digital converter after the corresponding down-conversion must be greater than 63.75MHz.

With the continuous improvement of the integrated circuit technology level, it is easy to design a phase-locked loop of about 10 GHz and process an intermediate frequency signal within 70 MHz, which makes the present invention more and more valuable. Through frequency planning, a single phase-locked loop can generate two local oscillator signals of different frequencies, which can support two different channels of down-conversion, filtering, amplification and analog-to-digital conversion, and realize 12 different frequency points such as GPS, Glonass, Galileo and Beidou. Navigation signal reception. Compared with the traditional four-channel receiving architecture, the phase-locked loop is reduced from four to one, which avoids the mutual interference of multiple phase-locked loop clocks. The number of low-noise amplifiers has also been reduced from four to one, and accordingly, mixers, filters, programmable amplifiers, and analog-to-digital converters have also been halved, greatly reducing chip area and power consumption.

For those skilled in the art, various other corresponding changes and deformations can be made according to the technical solutions and concepts described above, and all these changes and deformations should fall within the protection scope of the claims of the present invention.

Claims (5)

1. A multi-mode navigation receiving device, comprising: an antenna, a low noise amplifier, a phase-locked loop, a first frequency divider, a second frequency divider, a first receiving channel and a second receiving channel; The radio frequency signal of the antenna is divided into two signals after passing through the low noise amplifier, one signal is processed by the first receiving channel and then output, and the other signal is processed by the second receiving channel and then output; The output frequency of the phase-locked loop is respectively input to the first frequency divider and the second frequency divider; the first frequency divider outputs two quadrature local oscillator signals to the first receiving channel, and the second frequency divider The device outputs two other quadrature local oscillator signals to the second receiving channel. 2. The multimode navigation receiving device according to claim 1, wherein the first receiving channel and the second receiving channel have the same structure: respectively comprise an I-way mixer, a Q-way mixer, two filters, two programmable amplifiers and two analog-to-digital converters; the input end of the I-channel mixer is connected to the low-noise amplifier, and the output end passes through a filter, a programmable amplifier and an analog-to-digital converter in sequence; the The input end of the Q-channel mixer is connected to the low-noise amplifier, and the output end passes through another filter, another programmable amplifier and another analog-to-digital converter in sequence and outputs; The first frequency divider outputs the quadrature I-channel local oscillator signal and the Q-channel local oscillator signal; the second frequency divider outputs another I-channel local oscillator signal and another Q-channel local oscillator signal that are orthogonal; The I-channel local oscillator signal of the first frequency divider is input to the I-channel mixer of the first receiving channel, and the Q-channel local oscillator signal is input to the Q-channel mixer of the first receiving channel; The I-channel local oscillator signal of the second frequency divider is input to the I-channel mixer of the second receiving channel, and the Q-channel local oscillator signal is input to the Q-channel mixer of the second receiving channel. 3. The multimode navigation receiving device according to claim 1, wherein the output frequency of the phase-locked loop is f _VCO , the frequency dividing ratio of the first frequency divider is 1:N1, the second frequency divider The frequency division ratio is 1:N2; and the following relationships are satisfied: 1165MHz≤f _VCO /N1≤1280MHz, 1560MHz≤f _VCO /N2≤1620MHz. 4. The multimode navigation receiving device according to claim 3, wherein the output frequency of the phase-locked loop is f _VCO =9720MHz, the frequency dividing ratio of the first frequency divider is 1:8, and the second frequency dividing The divider ratio is 1:6. 5. The multi-mode navigation receiving device according to claim 1, wherein the low noise amplifier, phase locked loop, first frequency divider, second frequency divider, first receiving channel and second receiving channel integrated in the same chip.

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