A continuous wave radar transceiver system

Abstract

The present invention relates to a continuous wave radar transceiver system, and belongs to the field of radar technology. The transceiver system includes a transmitting link, a receiving link, a reference source link, a de-skewing link, and a power supply monitoring link; the receiving link adopts a receiving method of de-skewing down-conversion and baseband demodulation to effectively suppress near-end leakage interference of transmission and reception. The transmitting link modulates, filters, and amplifies the baseband signal, and the modulation array is provided by an internal reference source link. The reference source link provides the array signal for the transceiver link and provides multi-channel clock signals for the digital. The present invention integrates the transmitting link, the receiving link, and the reference source link into one, has complete functions, compact structure, small size, light weight, and good stability and reproducibility.

Description

Technical Field

[0001] The invention belongs to the technical field of radar, and in particular relates to a continuous wave radar transceiver system. Background Art

[0002] In recent years, with the development of small drones, airborne radars that fly at low altitudes and have a short range have received widespread attention. In order to meet the requirements of the platform, the radar needs to achieve high system integration, miniaturization, light weight, and low power consumption without changing its performance, and can be flexibly mounted on various platforms. Continuous wave radars are light in weight, small in size, and low in power consumption, but the receiving and transmitting antennas of continuous wave radars work at the same time and the two antennas are very close to each other, so the "leakage" of the transmitted signal to the receiving channel is relatively serious. The issue of transmit and receive isolation has always been the main factor restricting the application and development of continuous wave radars.

[0003] Since the receiving and transmitting antennas of the continuous wave radar work simultaneously and the two antennas are very close to each other, the "leakage" of the transmitting signal to the receiving channel is relatively serious. First, a strong leakage signal will saturate the amplifier and even the mixer and low noise amplifier. Second, the transmitter noise will leak to the receiver, causing the receiver sensitivity to decrease. Third, due to the existence of the leakage phenomenon, false Doppler signals will be generated.

[0004] Traditional radars have always been dominated by pulse radars. The reason is that in single-station radars with a shared antenna for transmission and reception, although pulse radars can use transceiver switches to easily isolate the transmitted pulse and the received pulse in the time domain, the defects of pulse radars, such as complex equipment, large size, heavy weight, and high requirements for the payload platform, are becoming increasingly prominent. Summary of the invention

[0005] In order to overcome the shortcomings of large system size, heavy weight and poor integration, the present invention proposes a radar transceiver system with small size, light weight and high integration.

[0006] The present invention provides a continuous wave radar transceiver system, including a signal transceiver link and a power supply monitoring link. The signal transceiver link includes a transmitting link, a reference source link, a de-skewing link, and a receiving link. The reference source link is respectively connected to the transmitting link, the de-skewing link, and the receiving link. The de-skewing link is also connected to the receiving link. The power supply monitoring link supplies power to the signal transceiver link.

[0007] Further, the transmission link includes a first transmission link baseband input SMA interface, a second transmission link baseband input SMA interface, a transmission link output SMA interface, a first baseband low-pass filter, a second baseband low-pass filter, a first radio frequency amplifier, a second radio frequency amplifier, an IQ modulator, a first bandpass filter, a first radio frequency amplifier, and a second bandpass filter;

[0008] The input end of the first baseband low-pass filter is connected to the first transmission link baseband input SMA interface, the output end of the first baseband low-pass filter is connected to the first input end of the IQ modulator through the first RF amplifier, the input end of the second baseband low-pass filter is connected to the second transmission link baseband input SMA interface, the output end of the second baseband low-pass filter is connected to the second input end of the IQ modulator through the second RF amplifier, the third input end of the IQ modulator is connected to the reference source link, the output end of the IQ modulator is connected to the input end of the second bandpass filter through the first bandpass filter and the first RF amplifier, and the output end of the second bandpass filter is connected to the transmission link output SMA interface.

[0009] Further, the reference source link includes a constant temperature crystal oscillator, a first amplifier, a first SRD frequency multiplier, a microstrip filter, a second RF amplifier, a first power divider, a first surface acoustic wave filter, a second amplifier, a second power divider, a third amplifier, a fourth amplifier, a second surface acoustic wave filter, a second SRD frequency multiplier, a fifth amplifier, a third power divider, a 9.6 GHz array output interface, a 1.6 GHz down-conversion array output interface, an AD clock output interface, a DA clock output interface, and a receiving and demodulating array output interface;

[0010] The constant temperature crystal oscillator is connected to the input end of the first power divider through the first amplifier and the first SRD frequency multiplier, the first output end of the first power divider is connected to the input end of the second power divider through the first acoustic surface filter and the second amplifier, the second output end of the first power divider is connected to the AD clock output interface through the second acoustic surface filter and the third amplifier, the first output end of the second power divider is connected to the 1.6 GHz down-conversion array output interface through the fourth amplifier, the 1.6 GHz down-conversion array output interface is connected to the de-skew link, the second output end of the second power divider is connected to the 9.6 GHz array output interface through the fifth amplifier, the second SRD frequency multiplier, the microstrip filter, and the second RF amplifier, the 9.6 GHz array output interface is connected to the third input end of the IQ modulator, the third output end of the second power divider is connected to the input end of the third power divider, the first output end and the second output end of the third power divider are respectively connected to the DA clock output interface and the receiving and demodulating array output interface, and the receiving and demodulating array output interface is connected to the receiving link.

[0011] Further, the de-skewing link includes a second bandpass filter, a first mixer, a third bandpass filter and a third radio frequency amplifier;

[0012] The second bandpass filter is connected to the first input end of the first mixer, the second input end of the first mixer is connected to the 1.6GHz down-conversion array output interface, the output end of the first mixer is connected to the input end of the fifth RF amplifier through the third bandpass filter, and the output end of the third RF amplifier is connected to the receiving link.

[0013] Further, the receiving link includes a first receiving link baseband output SMA interface, a second receiving link baseband output SMA interface, a third RF amplifier, a fourth RF amplifier, a fourth bandpass filter, a fifth bandpass filter, an IQ demodulator, an MGC gain controller, a sixth amplifier, a sixth bandpass filter, a second mixer, a seventh bandpass filter and a receiving link input SMA interface;

[0014] The first receiving link baseband output SMA interface is connected to the first output end of the IQ demodulator through the third RF amplifier and the fourth bandpass filter, the second receiving link baseband output SMA interface is connected to the second output end of the IQ demodulator through the fourth RF amplifier and the fifth bandpass filter, the first input end of the IQ demodulator is connected to the receiving demodulator array output interface, the second input end of the IQ demodulator is connected to the output end of the second mixer through the MGC gain controller, the sixth amplifier, and the sixth bandpass filter, the first input end of the second mixer is connected to the receiving link input SMA interface through the seventh bandpass filter, and the second input end of the second mixer is connected to the output end of the third RF amplifier.

[0015] Further, the power supply / monitoring link includes a power module, a secondary power conversion module, a monitoring module, a power supply interface, a through-hole capacitor power supply interface, a jumper and a power supply output interface;

[0016] The power supply interface is connected to the input end of the power module, the output end of the power module is connected to the input end of the secondary power conversion module, the first output end of the secondary power conversion module is connected to the through-hole capacitor power supply interface, the second output end of the power module is connected to the power supply output interface, the input end of the monitoring module is connected to the jumper, and the through-hole capacitor power supply interface and the jumper are both connected to the signal transceiver link.

[0017] The present invention has the following beneficial effects:

[0018] The system design of the present invention can effectively suppress the near-end leakage interference of the continuous wave radar transmitting and receiving antenna, and effectively suppress the leakage signal to a sufficiently low level through the isolation of transmission and reception, wherein the receiving link adopts a receiving method of dechirping to the intermediate frequency and then performing baseband demodulation on the intermediate frequency, realizing the selection of useful signals in the intermediate frequency band, and realizing the effective suppression of the near-end leakage interference of transmission and reception in the baseband filtering. The transmitting link adopts a transmitting link of direct orthogonal debugging, which is simple in design, has few components and low cost; the transmitting signal of the transmitting link is coupled with a reference source local oscillator signal to mix, and a down-converted signal is generated as the de-skewed local oscillator signal of the receiving link; the reference source module is based on a reference frequency, and generates multiple operating frequencies by combing the spectrum, which are selected through the filter to generate a fully coherent, high frequency stability and low phase noise clock and local oscillator signal; the system power supply and monitoring module provides secondary power for the entire system, and generates the telemetry signal of the radio frequency part at the same time, and the power supply adopts the through-hole capacitor to power the radio frequency.

[0019] The system integrates the transmitting link, receiving link, reference source link and power supply monitoring module into one, with complete functions, compact structure, small size and light weight, which reduces the assembly complexity of the whole machine and has good stability and reproducibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the components of the present invention;

[0021] Figure 2 It is a schematic block diagram of the transmission link principle of the present invention;

[0022] Figure 3 It is a schematic block diagram of the de-skew link principle of the present invention;

[0023] Figure 4 It is a schematic block diagram of the reference source link principle of the present invention;

[0024] Figure 5 It is a schematic block diagram of the receiving link principle of the present invention;

[0025] Figure 6 It is a schematic block diagram of the power supply monitoring link principle of the present invention;

[0026] Attached Figure 1Marking description: 1-transmitting link, 2-de-skewing link, 3-reference source link, 4-receiving link, 5-power supply monitoring link, 6-first transmitting link baseband input SMA interface, 7-second transmitting link baseband input SMA interface, 8-transmitting link output SMA interface, 9-de-skewing link input SMA interface, 10-receiving link input SMA interface, 11-first receiving link baseband output SMA interface, 12-second receiving link baseband output SMA interface, 13-power supply interface, 14-through capacitor power supply interface, 15-jumper, 16-power supply output interface;

[0027] Attached Figure 2 Label description: 201-first baseband low-pass filter, 202-second baseband low-pass filter, 203-first radio frequency amplifier, 204-second radio frequency amplifier, 205-IQ modulator, 206-first band-pass filter, 207-first radio frequency amplifier, 208-second band-pass filter;

[0028] Attached Figure 3 Label description: 301 - third band-pass filter, 302 - first mixer, 303 - fourth band-pass filter, 304 - third radio frequency amplifier;

[0029] Attached Figure 4 Marking description: 401- constant temperature crystal oscillator, 402- first amplifier, 403- second SRD frequency multiplier, 404- microstrip filter, 405- second RF amplifier, 406- first power divider, 407- first surface acoustic filter, 408- second amplifier, 409- second power divider, 410- fourth amplifier, 411- third amplifier, 412- second surface acoustic filter, 413- first SRD frequency multiplier, 414- fifth amplifier, 415- third power divider, 416- 9.6 GHz array output, 417- 1.6 GHz down-conversion array output, 418- AD clock output, 419- DA clock output, 420- receiving and demodulating array output;

[0030] Attached Figure 5 Label description: 501-third RF amplifier, 502-fifth band-pass filter, 503-fourth RF amplifier, 504-sixth band-pass filter, 505-IQ demodulator, 506-MGC gain controller, 507-sixth amplifier, 508-seventh band-pass filter, 509-second mixer, 510-eighth band-pass filter;

[0031] Attached Figure 6 Marking description: 601-power module, 602-secondary power conversion module, 603-monitoring module; Specific implementation methods

[0032] Referring to the above drawings, the present invention relates to a continuous wave radar transceiver system (see Figure 1 ), mainly includes a transmitting link 1, a de-skewing link 2, a reference source link 3, a receiving link 4 and a power supply monitoring link 5: wherein the first transmitting link baseband input SMA interface 6 and the second transmitting link baseband input SMA interface 7 of the transmitting link are both connected to the digital DA signal, and the transmitting link output SMA interface 8 is connected to the power amplifier module; the de-skewing link is connected to the transmitting coupling reference signal through the de-skewing link input SMA port 9; the clock and local oscillator signals generated by the reference source link are connected through the microstrip line and the inter-board connector; the receiving link is connected to the digital AD through the first receiving link baseband output SMA interface 11 and the second receiving link baseband output SMA interface 12, and is also connected to the external low noise amplifier through the receiving link input SMA interface 10; the power supply monitoring link is connected to the power supply system through the power supply interface 13, supplies power to other links through the power supply through-capacitor power supply interface 14, connects the monitoring signal through the jumper 15, and supplies power to the external power amplifier and low noise amplifier through the power supply output interface 16.

[0033] Transmit link 1 (see Figure 2 ) receives the baseband signal generated by the digital DA, passes through the first baseband low-pass filter 201 and the second baseband low-pass filter 202 to filter out the out-band clutter, enters the first RF amplifier 203 and the second RF amplifier 204 for signal amplification, the amplified signal is modulated to RF by the IQ modulator 205, the RF signal passes through the first bandpass filter 206 to filter out the out-band clutter, then passes through the first RF amplifier 207 for power amplification, and finally passes through the second bandpass filter 208 to output to the antenna front-end power amplifier module. The transmission signal requires high out-of-band suppression, high image frequency suppression and good flatness performance.

[0034] De-slant link 2 (see Figure 3 ) A de-skewed reference signal coupled from a transmitting link is received, out-of-band clutter is filtered out by a third band-pass filter 301, mixed with an intermediate frequency local oscillator signal by a first mixer 302, and the mixed output signal is again filtered out-of-band clutter by a fourth band-pass filter 303. The mixed output signal is power amplified by a third RF amplifier 304, amplified to a signal that meets the power requirement of the de-skewed array, and output to the receiving link for de-skew mixing.

[0035] Reference source link (see Figure 4) The design adopts a direct frequency doubling method. The output signal of the 100M constant temperature crystal oscillator 401 is amplified by the first amplifier 402. The amplified output signal drives the first SRD frequency multiplier 413 to generate multiple frequency doubling signals. The generated comb signal is first divided into two paths by the first power divider 406: one path is selected by the second SAW filter 412 to obtain a point frequency signal, and the point frequency signal is amplified by the third amplifier 411 and output to the digital board as an AD acquisition clock signal; the other comb signal is passed through the first SAW filter 407 to obtain another point frequency signal, and the point frequency signal is divided into three point frequency signals by the second power divider 409. One of the point frequency signals is split into two paths by the third power divider 415, which are used as the DA clock signal and the demodulated local oscillator signal of the receiving link respectively; one path is power amplified again by the fourth amplifier 410 to output the signal as the down-conversion mixed local oscillator signal of the de-skewed reference signal; the other path is amplified by the fifth amplifier 414, and then passes through the second SRD multiplier 403 to generate a higher-order multiplied signal. The signal passes through the microstrip filter 404 and the second RF amplifier 405 to finally obtain the transmit modulated local oscillator signal.

[0036] Receive link (see Figure 5 ) receives the echo signal amplified by the low noise amplifier, the signal is first filtered by the eighth band pass filter 510, the filtered signal is mixed with the de-skewed local oscillator signal by the second mixer 509 to obtain the de-skewed intermediate frequency signal, the intermediate frequency signal is filtered by the seventh band pass filter 508 to filter out unwanted signal components, and then the signal is sent to the sixth amplifier 507 for intermediate frequency signal power amplification, the amplified signal is sent to the MGC gain controller 506 to realize gain control, the intermediate frequency signal is adjusted to a suitable level range through gain control and then sent to the IQ demodulator 505 for baseband demodulation, in order to suppress the near-end leakage signal of the transmission and reception, the demodulated signal is first filtered by the sixth band pass filter 504 and the fifth band pass filter 502 to filter out the high-frequency clutter signal and the leakage signal of the zero-frequency annex, and finally the signal is amplified again by the fourth radio frequency amplifier 503 and the third radio frequency amplifier 501, and the obtained video output is sent to the AD for digital acquisition.

[0037] Power supply monitoring link (see Figure 6 ) The power supply is uniformly provided by a 28V DC power supply, which is converted by the DC-DC power supply module 601 and the DC-DC secondary power conversion module 602 to generate positive and negative voltages, which are supplied to each link respectively. The power supply and main signal points are equipped with level monitoring circuits, and the monitoring module 603 realizes level monitoring and MGC gain control to ensure that the equipment can be quickly checked and located when a fault occurs. The power supply adopts the PCB bottom board power supply method. The PCB power supply board is located at the back of the cavity, and the through-hole capacitor is used to provide RF power for the front cavity.

[0038] In terms of structural design, the present invention integrates discrete components such as the transmitting link, receiving link, de-skewing link and reference source link into the same structure, adopts a cavity design in the structure to increase the isolation between link units, and uses impedance microstrip lines for internal interconnection. On the basis of completing the established functional performance, the system integration is improved, the space is saved to the maximum extent, and the weight is effectively reduced. The external box body is processed and assembled from aluminum alloy plates, the interior of the box body adopts a cavity design, and the box body wall adopts a groove design. It has sufficient strength and rigidity while being relatively light, effectively reducing weight and having good heat dissipation performance.

Claims

1. A continuous wave radar transceiver system, characterized in that: It includes a signal transceiver link and a power supply monitoring link, wherein the signal transceiver link includes a transmitting link, a reference source link, a de-skewing link, and a receiving link, the reference source link is respectively connected to the transmitting link, the de-skewing link, and the receiving link, the de-skewing link is also connected to the receiving link, and the power supply monitoring link supplies power to the signal transceiver link and performs a monitoring signal connection with the signal transceiver link; The transmission link includes a first transmission link baseband input SMA interface, a second transmission link baseband input SMA interface, a transmission link output SMA interface, a first baseband low-pass filter, a second baseband low-pass filter, a first radio frequency amplifier, a second radio frequency amplifier, an IQ modulator, a first bandpass filter, a first radio frequency amplifier, and a second bandpass filter; The input end of the first baseband low-pass filter is connected to the first transmission link baseband input SMA interface, the output end of the first baseband low-pass filter is connected to the first input end of the IQ modulator through the first radio frequency amplifier, the input end of the second baseband low-pass filter is connected to the second transmission link baseband input SMA interface, the output end of the second baseband low-pass filter is connected to the second input end of the IQ modulator through the second radio frequency amplifier, the third input end of the IQ modulator is connected to the reference source link, the output end of the IQ modulator is connected to the input end of the second bandpass filter through the first bandpass filter and the first radio frequency amplifier, and the output end of the second bandpass filter is connected to the transmission link output SMA interface; The reference source link includes a constant temperature crystal oscillator, a first amplifier, a first SRD frequency multiplier, a microstrip filter, a second radio frequency amplifier, a first power divider, a first surface acoustic wave filter, a second amplifier, a second power divider, a third amplifier, a fourth amplifier, a second surface acoustic wave filter, a second SRD frequency multiplier, a fifth amplifier, a third power divider, a 9.6 GHz array output interface, a 1.6 GHz down-conversion array output interface, an AD clock output interface, a DA clock output interface, and a receiving and demodulating array output interface; The constant temperature crystal oscillator is connected to the input end of the first power divider through the first amplifier and the first SRD frequency multiplier, the first output end of the first power divider is connected to the input end of the second power divider through the first acoustic surface filter and the second amplifier, the second output end of the first power divider is connected to the AD clock output interface through the second acoustic surface filter and the third amplifier, the first output end of the second power divider is connected to the 1.6 GHz down-conversion array output interface through the fourth amplifier, the 1.6 GHz down-conversion array output interface is connected to the de-skew link, the second output end of the second power divider is connected to the 9.6 GHz array output interface through the fifth amplifier, the second SRD frequency multiplier, the microstrip filter, and the second RF amplifier, the 9.6 GHz array output interface is connected to the third input end of the IQ modulator, the third output end of the second power divider is connected to the input end of the third power divider, the first output end and the second output end of the third power divider are respectively connected to the DA clock output interface and the receiving and demodulating array output interface, and the receiving and demodulating array output interface is connected to the receiving link; The de-skewing link includes a third bandpass filter, a first mixer, a fourth bandpass filter and a third radio frequency amplifier; The third band-pass filter is connected to the first input end of the first mixer, the second input end of the first mixer is connected to the 1.6 GHz down-conversion array output interface, the output end of the first mixer is connected to the input end of the fifth radio frequency amplifier through the fourth band-pass filter, and the output end of the third radio frequency amplifier is connected to the receiving link; The receiving link includes a first receiving link baseband output SMA interface, a second receiving link baseband output SMA interface, a third RF amplifier, a fourth RF amplifier, a fifth bandpass filter, a sixth bandpass filter, an IQ demodulator, an MGC gain controller, a sixth amplifier, a seventh bandpass filter, a second mixer, an eighth bandpass filter and a receiving link input SMA interface; The first receiving link baseband output SMA interface is connected to the first output end of the IQ demodulator through the third RF amplifier and the fifth bandpass filter, the second receiving link baseband output SMA interface is connected to the second output end of the IQ demodulator through the fourth RF amplifier and the sixth bandpass filter, the first input end of the IQ demodulator is connected to the receiving demodulator array output interface, the second input end of the IQ demodulator is connected to the output end of the second mixer through the MGC gain controller, the sixth amplifier, and the seventh bandpass filter, the first input end of the second mixer is connected to the receiving link input SMA interface through the eighth bandpass filter, and the second input end of the second mixer is connected to the output end of the third RF amplifier; The power supply monitoring link includes a power supply module, a secondary power supply conversion module, a monitoring module, a power supply interface, a through-hole capacitor power supply interface, a jumper and a power supply output interface; The power supply interface is connected to the input end of the power module, the output end of the power module is connected to the input end of the secondary power conversion module, the first output end of the secondary power conversion module is connected to the through-hole capacitor power supply interface, the second output end of the power module is connected to the power supply output interface, the input end of the monitoring module is connected to the jumper, and the through-hole capacitor power supply interface and the jumper are both connected to the signal transceiver link; The system design can effectively suppress the near-end leakage interference of the continuous wave radar transmitting and receiving antennas, and effectively suppress the leakage signal to a sufficiently low level through the isolation of transmission and reception. Among them, the receiving link adopts a receiving method of de-modulating to the intermediate frequency and then baseband demodulating the intermediate frequency, realizing the selection of useful signals in the intermediate frequency band, and realizing the effective suppression of near-end leakage interference of transmission and reception through baseband filtering; the transmitting link adopts a direct orthogonal debugging transmitting link, which is simple in design, has few components and low cost; the transmitting signal of the transmitting link is coupled with the reference source local oscillator signal to mix, and a down-converted signal is generated as the de-skewed local oscillator signal of the receiving link; the reference source module uses a reference frequency as the reference, generates multiple operating frequencies by combing the spectrum, and selects through the filter to generate fully coherent, high frequency stability and low phase noise clock and local oscillator signals; The discrete components of the transmitting link, receiving link, de-skewing link and reference source link are integrated into the same structure. A cavity design is used within the structure to increase the isolation between link units, and impedance microstrip lines are used for internal interconnection. This improves the system's integration while completing the established functional performance, saves space to the maximum extent, and effectively reduces weight.

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