CN117169819A

CN117169819A - Radar transceiver

Info

Publication number: CN117169819A
Application number: CN202311162732.6A
Authority: CN
Inventors: 余振兴; 赵�衍
Original assignee: Taijing Technology Nanjing Co ltd
Current assignee: Taijing Technology Nanjing Co ltd
Priority date: 2023-09-08
Filing date: 2023-09-08
Publication date: 2023-12-05

Abstract

The application provides a radar transceiver, and relates to the technical field of electronics. The radar transceiver includes: transmitter, receiver and signal generation module, wherein, the transmitter includes: a modulation module, a power amplifier and a transmitting antenna; the receiver includes: a receiving antenna, a low noise amplifier and a mixing module; the first input end of the modulation module is used for receiving an amplitude modulation or phase modulation signal, and the second input end of the modulation module is connected with the signal generation module so as to receive a frequency modulation signal; the output end of the modulation module is connected with a transmitting antenna through a power amplifier and is used for outputting radio frequency signals; the receiving antenna is connected with a first input end of the frequency mixing module through the low-noise amplifier, and a second input end of the frequency mixing module is also connected with the signal generating module so as to receive the frequency modulation signal; the output end of the mixing module is used for outputting an intermediate frequency signal. The application can avoid the interference of external factors and the low-frequency 1/f noise of the receiver, and improve the target detection imaging effect of the radar transceiver.

Description

Radar transceiver

Technical Field

The application relates to the technical field of electronics, in particular to a radar transceiver.

Background

The millimeter wave radar obtains information such as distance, speed and angle of a detected target by using a beating signal of a transmitting signal and an echo signal, and has the advantages of simple structure, small size, light weight, low cost and the like, and is widely applied to the fields of military security, automobile auxiliary driving, industrial detection, intelligent home, security imaging and the like in recent years.

The conventional millimeter wave radar transceiver is a zero intermediate frequency transceiver architecture, and the calculation formula of the beat signal frequency of the zero intermediate frequency transceiver can be expressed as follows: if=2r×k/c, where R is the distance between the measured object and the transceiver, k is the waveform slope of the frequency modulation signal of the transceiver, and c is the light velocity, and according to this calculation formula, it can be seen that, during near-distance imaging, because the distance between the measured object and the transceiver is very short, the beat signal frequency of the transceiver is very low, and the influence of factors such as low-frequency 1/f noise of the receiver, local oscillation signal leakage and near-distance obstacle reflection, causes the signal-to-noise ratio of the intermediate frequency signal to be relatively poor, resulting in poor target detection imaging effect in the near-distance range.

Disclosure of Invention

The application aims to overcome the defects in the prior art and provide a radar transceiver so as to avoid interference of external factors and improve the target detection imaging effect of the radar transceiver.

In order to achieve the above purpose, the technical scheme adopted by the embodiment of the application is as follows:

in a first aspect, an embodiment of the present application provides a radar transceiver, including: a transmitter, a receiver, and a signal generation module, wherein the transmitter comprises: a modulation module, a power amplifier and a transmitting antenna; the receiver includes: a receiving antenna, a low noise amplifier and a mixing module;

the first input end of the modulation module is used for receiving an amplitude modulation or phase modulation signal, and the second input end of the modulation module is connected with the signal generation module so as to receive a frequency modulation signal; the output end of the modulation module is connected with the transmitting antenna through the power amplifier and is used for outputting radio frequency signals;

the receiving antenna is connected with the first input end of the frequency mixing module through the low noise amplifier, and the second input end of the frequency mixing module is also connected with the signal generating module so as to receive the frequency modulation signal; the output end of the mixing module is used for outputting an intermediate frequency signal.

In one possible implementation, the signal generating module includes: a signal generator and a frequency multiplier;

the signal generator is connected with the input end of the frequency multiplier, and the output end of the frequency multiplier is used for outputting the frequency modulation signal.

In one possible implementation manner, if the modulation module is a double-sideband modulation module, a first input end of the double-sideband modulation module is used for receiving the amplitude modulation or phase modulation signal, and a second input end of the double-sideband modulation module is connected with an output end of the frequency multiplier so as to receive the frequency modulation signal;

if the receiver is a real receiver, the mixing module includes: the first input end of the one mixer is connected with the output end of the low noise amplifier, and the second input end of the one mixer is connected with the output end of the frequency multiplier so as to receive the frequency modulation signal as a local oscillation signal; the output end of the one mixer is used for outputting the intermediate frequency signal.

In one possible implementation, the receiver further includes: a variable gain transimpedance amplifier;

the output end of the mixer is connected with the input end of the variable gain transimpedance amplifier, and the output end of the variable gain transimpedance amplifier is used for outputting the intermediate frequency signal.

In one possible implementation manner, if the modulation module is a single sideband modulation module, the signal generating module further includes: the input end of the in-phase quadrature generator is connected with the output end of the frequency multiplier so as to generate in-phase frequency modulation signals and quadrature frequency modulation signals corresponding to the frequency modulation signals; the in-phase input end and the quadrature input end of the single-sideband modulation module are respectively connected with the in-phase output end and the quadrature output end of the in-phase quadrature generator so as to receive the in-phase frequency modulation signal and the quadrature frequency modulation signal;

if the receiver is a quadrature receiver, the mixing module includes: the first input end of the first mixer and the first input end of the second mixer are connected with the output end of the low-noise amplifier, the second input end of the first mixer is connected with the in-phase output end of the in-phase quadrature generator so as to receive the in-phase frequency modulation signal, and the second input end of the second mixer is connected with the quadrature output end of the in-phase quadrature generator so as to receive the quadrature frequency modulation signal; the output end of the first mixer is used for outputting an in-phase intermediate frequency signal, and the output end of the second mixer is used for outputting a quadrature intermediate frequency signal.

In one possible implementation, the receiver further includes: a first variable gain transimpedance amplifier and a second variable gain transimpedance amplifier;

the output end of the first mixer is connected with the input end of the first variable gain transimpedance amplifier, and the output end of the first variable gain transimpedance amplifier is used for outputting the in-phase intermediate frequency signal;

the output end of the second mixer is connected with the input end of the second variable gain transimpedance amplifier, and the output end of the second variable gain transimpedance amplifier is used for outputting the quadrature intermediate frequency signal.

In one possible implementation manner, if the modulation module is a double sideband modulation module, the signal generating module further includes: the input end of the in-phase quadrature generator is connected with the output end of the frequency multiplier so as to generate in-phase frequency modulation signals and quadrature frequency modulation signals corresponding to the frequency modulation signals; the second input end of the double-sideband modulation module is connected with the in-phase output end of the in-phase quadrature generator so as to receive the in-phase frequency modulation signal;

In one possible implementation, the modulation module includes: a modulator and a radio frequency variable gain amplifier;

the first input end and the second input end of the modulation module are respectively the first input end and the second input end of the modulator, the output end of the modulator is connected with the input end of the radio frequency variable gain amplifier, and the output end of the radio frequency variable gain amplifier is the output end of the modulation module.

In one possible implementation, the modulation module is an integrated module with a signal modulation unit and a gain amplification unit.

The beneficial effects of the application are as follows:

according to the radar transceiver provided by the application, when the modulation module modulates signals according to the frequency modulation signals and the amplitude modulation or phase modulation signals, fixed frequency offset is generated on the radio frequency signals, so that the lower intermediate frequency beat frequency of the intermediate frequency signals generated during near-range detection imaging is translated into a proper intermediate frequency range to process the intermediate frequency signals, the influence of local oscillator signal leakage or near-range obstacle strong reflection interference is solved, the signal-to-noise ratio of the intermediate frequency signals received by the receiver is improved, the quality of the received intermediate frequency signals is ensured, and the near-range detection imaging effect is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic block diagram of a conventional millimeter wave radar transceiver;

FIG. 2 is an intermediate frequency beat spectrum diagram of a conventional millimeter wave radar transceiver;

FIG. 3 is a schematic block diagram of a radar transceiver according to an embodiment of the present application;

FIG. 4 is a diagram of an intermediate frequency beat spectrum of a radar transceiver according to an embodiment of the present application;

fig. 5 is a schematic block diagram of a radar transceiver according to an embodiment of the present application;

fig. 6 is a schematic diagram of a radar transceiver according to an embodiment of the present application;

fig. 7 is a schematic diagram of a second radar transceiver according to an embodiment of the present application;

fig. 8 is a schematic diagram of a radar transceiver according to an embodiment of the present application;

fig. 9 is a schematic diagram of a radar transceiver according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application.

Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Furthermore, the terms first, second and the like in the description and in the claims and in the above-described figures, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

It should be noted that the features of the embodiments of the present application may be combined with each other without conflict.

Referring to fig. 1, which is a schematic structural diagram of a conventional millimeter wave radar transceiver, as shown in fig. 1, the conventional millimeter wave radar transceiver includes: a signal generator, an M frequency multiplier, a Power Amplifier (PA), a Low noise Power amplifier (Low Noise Amplifier, LNA), a MIXER (MIXER), a Low Pass Filter (LPF), a High Power Field (HPF), an intermediate frequency variable gain amplifier (Intermediate Frequency Variable Gain Amplifier, IFVGA), a transmit Antenna (Transmitter Antenna), and a receive Antenna (Receiver Antenna).

The signal generator is connected with the input end of the M frequency multiplier, and is used for generating a frequency modulation continuous wave (Frequency Modulated Continuous Wave, FMCW) modulation signal, and the M frequency multiplier is used for multiplying the FMCW modulation signal; the output end of the M frequency multiplier is connected with a transmitting antenna through a power amplifier and is used for outputting radio frequency signals.

The receiving antenna is connected with a first input end of the mixer through the low-noise amplifier, a second input end of the mixer is connected with an output end of the M frequency multiplier, and the output end of the mixer is sequentially connected with the low-pass filter, the intermediate frequency variable gain amplifier and the high-pass filter so as to output intermediate frequency signals.

For the radar transceiver shown in fig. 1, in a close range detection application (for example, within a few millimeters to tens of centimeters), such as a high-performance security imaging radar, the requirement on the radar transceiver is high, the transverse resolution of the transceiver imaging is determined by the radio frequency, the radial resolution of the transceiver imaging is determined by the continuous sweep bandwidth, and in addition, the signal-to-noise ratio requirement on the receiver signal is high for high-precision imaging.

As can be seen from the formula if=2r×k/c of the relation between the receiver beat intermediate frequency signal and the detection distance of the FMCW mode radar, the frequency of the beat signal of the transceiver is low (located near the near-zero frequency component) because the distance from the detected object to the transceiver is short during the short-range detection imaging.

Referring to fig. 2, an intermediate frequency beat spectrum diagram of a conventional millimeter wave radar transceiver is shown in fig. 2, at this distance, low frequency noise of the transceiver is very large, and due to the influence of factors such as local oscillator leakage or strong reflection of a close range obstacle of the receiver, intermediate frequency signals of the receiver have a lot of low frequency components close to the vicinity of direct current, so that signal-to-noise ratio of the intermediate frequency signals received by the receiver is poor, and interference of the close range obstacle to a target to be measured is also very large.

Based on the above, the application aims to provide a radar transceiver, which generates an additional frequency offset during near-distance detection imaging so as to translate the lower intermediate frequency beat frequency of the intermediate frequency signal generated during near-distance detection imaging into a proper intermediate frequency range for processing the intermediate frequency signal, thereby solving the influence of local oscillation signal leakage or strong reflection interference of near-distance obstacles, improving the signal-to-noise ratio of the intermediate frequency signal received by a receiver, ensuring the quality of the received intermediate frequency signal and further improving the near-distance detection imaging effect.

Referring to fig. 3, a schematic block diagram of a radar transceiver according to an embodiment of the present application is shown in fig. 3, where the radar transceiver 100 includes: a transmitter 10, a receiver 20, and a signal generation module 30, wherein the transmitter 10 comprises: a modulation module 101, a power amplifier 102 and a transmitting antenna 103; the receiver 20 includes: a receiving antenna 201, a low noise amplifier 202 and a mixing module 203.

A first input end of the modulation module 101 is used for receiving an amplitude modulation or phase modulation signal, and a second input end of the modulation module 101 is connected with the signal generation module 30 so as to receive a frequency modulation signal; the output end of the modulation module 101 is connected with a transmitting antenna 103 through a power amplifier 102 for outputting radio frequency signals.

The receiving antenna 201 is connected with a first input end of the mixing module 203 through the low noise amplifier 202 to receive signals reflected by a target to be detected, and a second input end of the mixing module 203 is also connected with the signal generating module 30 to receive frequency modulation signals; the output of the mixing module 203 is used for outputting an intermediate frequency signal (IF).

In this embodiment, the signal generating module 30 is configured to generate a frequency modulated signal, more specifically, an FMCW modulated signal, and provide the frequency modulated signal to the modulating module 101 in the transmitter 10 and the mixing module 203 in the receiver 20, respectively.

The modulation module 101 is used for receiving, in addition to the frequency modulation signal provided by the signal generation module 30, an amplitude modulation signal or a phase modulation signal, wherein the frequency modulation signal is used as a carrier signal, and the amplitude modulation signal or the phase modulation signal is used as a modulation signal, and the modulation module 101 multiplies the frequency f in the time domain when modulating the frequency modulation signal _m Can realize frequency shifting and generate a fixed frequency offset f _m The fixed frequency offset does not change with the detection distance. The modulation module 101 amplifies the power of the radio frequency signal by the power amplifier 102 and transmits the radio frequency signal to the target to be detected through the transmitting antenna 103. The amplification power of the power amplifier 102 may be based on the distance between the radar transceiver and the target to be measured, the reflection section of the receiving antenna of the radar transceiver, the antenna gain, and the antenna gainAnd determining the characteristics such as the number of the receiving and transmitting channels.

The receiving antenna 201 receives a reflected signal generated by an object to be measured based on a radio frequency signal, and performs undistorted linear amplification on the reflected signal by the low noise amplifier 202, since the radio frequency signal of the transmitter has a fixed frequency offset f _m The received reflected RF signal of the object to be measured also has a fixed frequency offset f _m The mixing module 203 mixes the received rf signal reflected by the object to be measured down based on the fm signal generated by the signal generating module 30, thereby obtaining an intermediate frequency signal with a fixed frequency offset.

For the radar transceiver shown in fig. 1, the radio frequency signal emitted by the transmitting antenna is a frequency modulated signal generated by the signal generator, and the frequency of the frequency modulated signal is f ₁ The frequency of the reflected signal received by the receiving antenna is f ₂ The frequency of the intermediate frequency signal after the frequency-modulated signal and the reflected signal are mixed by the mixer is f ₁ -f ₂ ＝f _b 。

Referring to fig. 4, an intermediate frequency beat spectrum diagram of a radar transceiver according to an embodiment of the present application is shown in fig. 4, and for the radar transceiver shown in fig. 3, the frequency of the fm signal provided by the signal generating module is f ₁ The radio frequency signal transmitted by the transmitting antenna has a fixed frequency offset f _m The frequency of the RF signal is f ₁ +f _m The frequency of the reflected signal received by the receiving antenna is f ₂ +f _m The frequency of the intermediate frequency signal after the frequency-modulated signal and the reflected signal are mixed by the mixer is f ₁ -f ₂ +f _m ＝f _b +f _m It can be seen from this that the fixed frequency offset generated by the radar transceiver provided in this embodiment can translate the lower intermediate frequency beat frequency of the intermediate frequency signal generated during the near-distance detection imaging into a suitable intermediate frequency range, so as to perform the processing of the intermediate frequency signal.

In one possible implementation, please refer to fig. 5, which is a second schematic block diagram of a radar transceiver provided in an embodiment of the present application, as shown in fig. 5, the modulation module 101 includes: a modulator 111 and a radio frequency variable gain amplifier 112; the first input end and the second input end of the modulation module 101 are respectively a first input end and a second input end of the modulator 111, an output end of the modulator 111 is connected with an input end of the radio frequency variable gain amplifier 112, and an output end of the radio frequency variable gain amplifier 112 is an output end of the modulation module 101.

In this embodiment, the modulation module 101 is formed by a modulator 111 and a radio frequency variable gain amplifier (Radio Frequency Variable Gain Amplifier, RFVGA) 112, where the modulator 111 is configured to generate a radio frequency signal with a fixed frequency offset according to the modulation signal and the amplitude modulation or phase modulation signal, the radio frequency variable gain amplifier 112 is configured to gain-amplify the radio frequency signal, and an output end of the radio frequency variable gain amplifier 112 is connected to a transmitting antenna through the power amplifier 102, and is configured to output the radio frequency signal subjected to gain amplification and power amplification.

In another possible implementation, the modulation module is an integrated module with a signal modulation unit and a gain amplification unit.

In this embodiment, the modulator and the rf variable-gain amplifier may be cooperatively designed so as to implement a signal modulation function of the modulator and a gain amplification function of the rf variable-gain amplifier based on one modulation module, so that power consumption and area of the modulation module may be received.

According to the radar transceiver provided by the embodiment, when the modulation module modulates signals according to the frequency modulation signals and the amplitude modulation or phase modulation signals, fixed frequency offset is generated on the radio frequency signals, so that the lower intermediate frequency beat frequency of the intermediate frequency signals generated during near-range detection imaging is translated into a proper intermediate frequency range to process the intermediate frequency signals, the influence of local oscillator signal leakage or near-range obstacle strong reflection interference is solved, the signal-to-noise ratio of the intermediate frequency signals received by the receiver is improved, the quality of the received intermediate frequency signals is guaranteed, and the near-range detection imaging effect is improved.

In one possible implementation, please refer to fig. 6, which is a schematic diagram of a radar transceiver according to an embodiment of the present application, as shown in fig. 6, the signal generating module 30 includes: a signal generator 31 and a frequency multiplier 32; the signal generator 31 is connected to an input of the frequency multiplier 32, and an output of the frequency multiplier 32 is used for outputting a frequency modulated signal.

In this embodiment, the signal generator 31 is used to generate an FMCW modulated signal, and the frequency multiplier 32 is used to multiply the FMCW modulated signal.

In some embodiments, if the modulation module 101 is a double-sideband modulation module 113, a first input terminal of the double-sideband modulation module 113 is configured to receive an amplitude modulation or a phase modulation signal, and a second input terminal of the double-sideband modulation module 113 is connected to an output terminal of the frequency multiplier 32 to receive the frequency modulation signal.

If the receiver 20 is a real receiver, the mixing module 203 includes: a mixer 231, a first input terminal of the mixer 231 is connected to the output terminal of the low noise amplifier 202, and a second input terminal of the mixer 231 is connected to the output terminal of the frequency multiplier 32 to receive the frequency modulated signal as a local oscillation signal; an output of one of the mixers 231 is for outputting an intermediate frequency signal.

In this embodiment, if the modulation module 101 is a double-sideband modulation module 113 and the receiver 20 is a real number receiver, the radar transceiver is a double-sideband modulation transmitting and real number receiving, and the double-sideband modulation module 113 is configured to perform double-sideband modulation (Double SideBand Suppressed Carrier Modulation, DSB-SC) on the fm signal according to the am or pm signal, and convert the fm signal into two double-sideband radio frequency signals with relatively high frequencies.

The receiver 20 is a real number receiver, and is configured to instruct the receiver 20 to perform real number decoding on a reflected signal, where in the case of real number decoding, the mixing module 203 is configured to include a mixer 231, after the reflected signal is amplified by the low noise amplifier 202, the mixer 231 mixes the frequency-modulated signal with the amplified reflected signal, and then outputs an intermediate frequency signal, so as to perform detection imaging on a measured object according to the intermediate frequency signal.

More specifically, if the modulation module 101 includes: the modulator 111 and the rf variable-gain amplifier 112 are shown in fig. 6, the modulator 111 is a double-sideband modulator, a first input terminal of the double-sideband modulator is used for receiving an amplitude modulation or a phase modulation signal, a second input terminal of the double-sideband modulator is connected to an output terminal of the frequency multiplier 32 for receiving a frequency modulation signal, and an output terminal of the double-sideband modulator is connected to the rf variable-gain amplifier 112.

The radar transceiver provided by the embodiment of the application is formed by the transmitter and the real number receiver corresponding to the double-sideband modulation module, and the radar transceiver with double-sideband modulation transmitting and real number receiving functions is realized to improve the close range detection imaging effect by utilizing the fixed frequency offset.

In some embodiments, as shown in fig. 6, the receiver 20 further comprises: the output end of the mixer 231 is connected with the input end of the variable gain transimpedance amplifier 204, and the output end of the variable gain transimpedance amplifier 204 is used for outputting an intermediate frequency signal.

In this embodiment, the variable gain transimpedance amplifier (VGTIA) 204 is composed of a Variable Gain Amplifier (VGA) and a transimpedance amplifier (Trans-Impedance Amplifier, TIA), and can replace the intermediate frequency filters (LPF and HPF) and the intermediate frequency variable gain amplifier in the receiver shown in fig. 1, so as to save the power consumption and area of the receiver.

According to the radar transceiver provided by the embodiment, the variable gain transimpedance amplifier is used for replacing the low-frequency filter, the high-frequency filter and the intermediate-frequency variable gain amplifier, so that on one hand, filtering of a reflected signal and intermediate-frequency gain amplification can be realized, and on the other hand, the power consumption and the area of a receiver can be reduced.

In one possible implementation, please refer to fig. 7, which is a schematic diagram of a radar transceiver according to an embodiment of the present application, as shown in fig. 7, if the modulation module 101 is a single sideband modulation module 114, the signal generating module 30 further includes: the in-phase and quadrature generator 33, wherein the input end of the in-phase and quadrature generator 33 is connected with the output end of the frequency multiplier 32 to generate an in-phase frequency modulation signal and a quadrature frequency modulation signal corresponding to the frequency modulation signal; the in-phase input and quadrature input of the single sideband modulation module 114 are connected to the in-phase output and quadrature output of the in-phase quadrature generator 33, respectively, to receive in-phase and quadrature frequency modulated signals.

If the receiver 20 is a quadrature receiver, the mixing module 203 includes: a first mixer 232 and a second mixer 233, wherein a first input terminal of the first mixer 232 and a first input terminal of the second mixer 233 are connected to an output terminal of the low noise amplifier 202, a second input terminal of the first mixer 232 is connected to an in-phase output terminal of the in-phase quadrature generator 33 to receive the in-phase frequency modulation signal, and a second input terminal of the second mixer 233 is connected to a quadrature output terminal of the in-phase quadrature generator 33 to receive the quadrature frequency modulation signal; the output of the first mixer 232 is used for outputting an in-phase intermediate frequency signal, and the output of the second mixer 233 is used for outputting a quadrature intermediate frequency signal.

In this embodiment, if the modulation module 101 is the single sideband modulation module 114 and the receiver 20 is the quadrature receiver, the radar transceiver is the single sideband modulation transmitting and quadrature receiving, and the mode of implementing the single sideband modulation by the single sideband modulation module 114 can be divided into a filtering method and an in-phase quadrature modulation method, where the filtering method is to perform band-pass filtering on the double sideband modulation signal, and only amplify the effective half-band modulation signal by the power amplifier 102 and transmit the amplified half-band modulation signal through the transmitting antenna. The IN-phase and Quadrature modulation method is to decompose the modulation signal to modulate the Quadrature (IN-phase) signal and the IN-phase (Quadrature) signal, respectively, and amplify them by the power amplifier 102, and transmit them through the transmitting antenna, so that half-band modulation can be achieved as well. The single sideband modulation module 114 of this embodiment implements single sideband modulation using an in-phase quadrature modulation method.

Specifically, an in-phase quadrature generator (IQ generator) 33 is connected between the output end of the frequency multiplier 32 and the input end of the Single-SideBand modulation module 114, where the in-phase quadrature generator 33 is configured to generate an in-phase frequency modulation signal and a quadrature frequency modulation signal according to the radio frequency signal output by the frequency multiplier 32, where the phase difference between the in-phase frequency modulation signal and the radio frequency signal is 90 °, and after the Single-SideBand modulation module 114 receives the in-phase frequency modulation signal and the quadrature frequency modulation signal, the in-phase frequency modulation signal and the quadrature frequency modulation signal are multiplied by an amplitude modulation signal or a phase modulation signal, and then the products are added to form a radio frequency signal, so as to implement Single-SideBand modulation (SSB) of the modulated signal.

The receiver 200 is a quadrature receiver, and is configured to instruct the receiver 20 to perform quadrature decoding on a reflected signal, where in the case of quadrature decoding, the mixing module 203 is configured by a first mixer 232 and a second mixer 233, where the reflected signal is amplified by the low noise amplifier 202, the first mixer 232 mixes an in-phase frequency modulated signal with the amplified reflected signal and outputs an in-phase intermediate frequency signal (IFI), and the second mixer 233 mixes the quadrature frequency modulated signal with the amplified reflected signal and outputs a quadrature intermediate frequency signal (IFQ), so as to perform detection imaging on a measured object according to the in-phase intermediate frequency signal and the quadrature intermediate frequency signal.

More specifically, if the modulation module 101 includes: a modulator 111 and a radio frequency variable gain amplifier 112, as shown in fig. 7, the modulator 111 is a single sideband modulator, a first input of the single sideband modulator is for receiving an amplitude modulated or phase modulated signal, and a second input of the single sideband modulator comprises: an in-phase input and a quadrature input, the in-phase input of the single sideband modulator is connected to the in-phase output of the in-phase quadrature generator 33 for receiving the in-phase frequency modulated signal, the quadrature input of the single sideband modulator is connected to the quadrature output of the in-phase quadrature generator 33 for receiving the quadrature frequency modulated signal, but the output of the sideband modulator is connected to the rf variable gain amplifier 112.

In some embodiments, as shown in fig. 7, the receiver 20 further comprises: a first variable gain transimpedance amplifier 205 and a second variable gain transimpedance amplifier 206.

The output end of the first mixer 232 is connected with the input end of the first variable gain transimpedance amplifier 205, and the output end of the first variable gain transimpedance amplifier 205 is used for outputting an in-phase intermediate frequency signal; an output terminal of the second mixer 233 is connected to an input terminal of the second variable gain transimpedance amplifier 206, and an output terminal of the second variable gain transimpedance amplifier 206 is configured to output a quadrature intermediate frequency signal.

The radar transceiver provided by the embodiment of the application is formed by the transmitter and the orthogonal receiver corresponding to the single sideband modulation module, and the radar transceiver with single sideband modulation transmitting and orthogonal receiving functions is realized to improve the close range detection imaging effect by utilizing the fixed frequency offset.

In one possible implementation, please refer to fig. 8, which is a schematic diagram of a radar transceiver according to an embodiment of the present application, as shown in fig. 8, if the modulation module 101 is a single sideband modulation module 114, the signal generating module 30 further includes: the in-phase and quadrature generator 33, wherein the input end of the in-phase and quadrature generator 33 is connected with the output end of the frequency multiplier 32 to generate an in-phase frequency modulation signal and a quadrature frequency modulation signal corresponding to the frequency modulation signal; the in-phase input and quadrature input of the single sideband modulation module 114 are connected to the in-phase output and quadrature output of the in-phase quadrature generator 33, respectively, to receive in-phase and quadrature frequency modulated signals.

If the receiver 20 is a real receiver, the mixing module 203 includes: a mixer 231, a first input terminal of the mixer 231 is connected to an output terminal of the low noise amplifier, and a second input terminal of the mixer 231 is connected to an output terminal of the frequency multiplier 32 to receive the frequency modulated signal as a local oscillation signal; an output of one of the mixers 231 is for outputting an intermediate frequency signal.

In this embodiment, if the modulation module 101 is the single sideband modulation module 114, and the receiver 20 is a real number receiver, the radar transceiver is single sideband modulation transmitting and real number receiving, in this case, an in-phase quadrature generator 33 is connected between the output end of the frequency multiplier 32 and the input end of the single sideband modulation module 114, and the in-phase quadrature generator 33 is configured to generate an in-phase frequency modulation signal and a quadrature frequency modulation signal according to the radio frequency signal output by the frequency multiplier 32, where the phase of the in-phase frequency modulation signal is the same as the phase of the radio frequency signal, the phase difference between the quadrature frequency modulation signal and the radio frequency signal is 90 °, and after the single sideband modulation module 114 receives the in-phase frequency modulation signal and the quadrature frequency modulation signal, the products of the in-phase frequency modulation signal and the quadrature frequency modulation signal are multiplied with the amplitude modulation signal or the phase modulation signal respectively, and then the products are added to obtain the single sideband modulation of the modulation signal.

More specifically, if the modulation module 101 includes: a modulator 111 and a radio frequency variable gain amplifier 112, as shown in fig. 8, the modulator 111 is a single sideband modulator, a first input of the single sideband modulator is for receiving an amplitude modulated or phase modulated signal, and a second input of the single sideband modulator comprises: an in-phase input and a quadrature input, the in-phase input of the single sideband modulator is connected to the in-phase output of the in-phase quadrature generator 33 for receiving the in-phase frequency modulated signal, the quadrature input of the single sideband modulator is connected to the quadrature output of the in-phase quadrature generator 33 for receiving the quadrature frequency modulated signal, but the output of the sideband modulator is connected to the rf variable gain amplifier 112.

In some embodiments, as shown in fig. 8, the receiver 20 further comprises: the output end of the mixer 231 is connected with the input end of the variable gain transimpedance amplifier 204, and the output end of the variable gain transimpedance amplifier 204 is used for outputting an intermediate frequency signal.

The radar transceiver provided by the embodiment of the application is formed by the transmitter and the real number receiver corresponding to the single sideband modulation module, and the radar transceiver with single sideband modulation transmitting and real number receiving functions is realized, and the radar transceiver with single sideband modulation transmitting and real number receiving functions utilizes fixed frequency offset to improve the close range detection imaging effect.

In one possible implementation, please refer to fig. 9, which is a schematic diagram of a radar transceiver according to an embodiment of the present application, as shown in fig. 9, if the modulation module 101 is a double-sideband modulation module 113, the signal generating module 30 further includes: the in-phase and quadrature generator 33, wherein the input end of the in-phase and quadrature generator 33 is connected with the output end of the frequency multiplier 32 to generate an in-phase frequency modulation signal and a quadrature frequency modulation signal corresponding to the frequency modulation signal; a second input of the double sideband modulation module 113 is connected to the in-phase output of the in-phase quadrature generator 33 for receiving the in-phase frequency modulated signal.

In this embodiment, if the modulation module 101 is a double-sideband modulation module 113 and the receiver 20 is a quadrature receiver, the radar transceiver is double-sideband modulation transmitting and quadrature receiving, in which case, the double-sideband modulation module 113 is configured to perform double-sideband modulation on the fm signal according to the am or pm signal, and decompose the fm signal into two relatively high frequency double-sideband rf signals.

More specifically, if the modulation module 101 includes: the modulator 111 and the rf variable-gain amplifier 112 are shown in fig. 9, the modulator 111 is a double-sideband modulator, a first input terminal of the double-sideband modulator is used for receiving an amplitude modulation or phase modulation signal, a second input terminal of the double-sideband modulator is connected to an in-phase output terminal of the in-phase quadrature generator 33 for receiving an in-phase frequency modulation signal, and an output terminal of the double-sideband modulator is connected to the rf variable-gain amplifier 112.

In some embodiments, as shown in fig. 9, the receiver 20 further comprises: a first variable gain transimpedance amplifier 205 and a second variable gain transimpedance amplifier 206.

The radar transceiver provided by the embodiment of the application is formed by the transmitter and the orthogonal receiver corresponding to the double-sideband modulation module, and the radar transceiver with double-sideband modulation transmitting and orthogonal receiving functions is realized to improve the close range detection imaging effect by utilizing the fixed frequency offset.

Based on the radar transceiver provided in the foregoing embodiment, as shown in fig. 6 to fig. 9, the embodiment of the present application provides four radar transceivers with different transceiver types, including: the radar transceiver with double-sideband modulation transmission and real number reception, the radar transceiver with single-sideband modulation transmission and quadrature reception, the radar transceiver with single-sideband modulation transmission and real number reception, the radar transceiver with double-sideband modulation transmission and quadrature reception, the modulation module in the radar transceiver with different transmission and reception types modulates the frequency modulation signal (or in-phase frequency modulation signal and quadrature frequency modulation signal) based on the amplitude modulation or phase modulation signal so as to generate the double-sideband transmission signal or single-sideband transmission signal with fixed frequency offset, so that the lower intermediate frequency beat frequency of the intermediate frequency signal generated during near-distance detection imaging is translated into a proper intermediate frequency range to process the intermediate frequency signal, the influence of local oscillator signal leakage or near-distance obstacle strong reflection interference is solved, the signal-to-noise ratio of the intermediate frequency signal received by the receiver is improved, the quality of the received intermediate frequency signal is ensured, and the near-distance detection imaging effect is improved.

The foregoing is merely illustrative of embodiments of the present application, and the present application is not limited thereto, and any changes or substitutions can be easily made by those skilled in the art within the technical scope of the present application, and the present application is intended to be covered by the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. A radar transceiver, the radar transceiver comprising: a transmitter, a receiver, and a signal generation module, wherein the transmitter comprises: a modulation module, a power amplifier and a transmitting antenna; the receiver includes: a receiving antenna, a low noise amplifier and a mixing module;

2. The radar transceiver of claim 1, wherein the signal generation module comprises: a signal generator and a frequency multiplier;

3. The radar transceiver of claim 2, wherein if the modulation module is a double sideband modulation module, a first input of the double sideband modulation module is configured to receive the amplitude modulation or phase modulation signal, and a second input of the double sideband modulation module is connected to an output of the frequency multiplier to receive the frequency modulation signal;

4. A radar transceiver according to claim 3, wherein the receiver further comprises: a variable gain transimpedance amplifier;

5. The radar transceiver of claim 2, wherein if the modulation module is a single sideband modulation module, the signal generation module further comprises: the input end of the in-phase quadrature generator is connected with the output end of the frequency multiplier so as to generate in-phase frequency modulation signals and quadrature frequency modulation signals corresponding to the frequency modulation signals; the in-phase input end and the quadrature input end of the single-sideband modulation module are respectively connected with the in-phase output end and the quadrature output end of the in-phase quadrature generator so as to receive the in-phase frequency modulation signal and the quadrature frequency modulation signal;

6. The radar transceiver of claim 5, wherein the receiver further comprises: a first variable gain transimpedance amplifier and a second variable gain transimpedance amplifier;

7. The radar transceiver of claim 2, wherein if the modulation module is a single sideband modulation module, the signal generation module further comprises: the input end of the in-phase quadrature generator is connected with the output end of the frequency multiplier so as to generate in-phase frequency modulation signals and quadrature frequency modulation signals corresponding to the frequency modulation signals; the in-phase input end and the quadrature input end of the single-sideband modulation module are respectively connected with the in-phase output end and the quadrature output end of the in-phase quadrature generator so as to receive the in-phase frequency modulation signal and the quadrature frequency modulation signal;

8. The radar transceiver of claim 2, wherein if the modulation module is a double sideband modulation module, the signal generation module further comprises: the input end of the in-phase quadrature generator is connected with the output end of the frequency multiplier so as to generate in-phase frequency modulation signals and quadrature frequency modulation signals corresponding to the frequency modulation signals; the second input end of the double-sideband modulation module is connected with the in-phase output end of the in-phase quadrature generator so as to receive the in-phase frequency modulation signal;

9. The radar transceiver of claim 1, wherein the modulation module comprises: a modulator and a radio frequency variable gain amplifier;

10. The radar transceiver of claim 1, wherein the modulation module is an integrated module having a signal modulation unit and a gain amplification unit.