A frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar

Abstract

The present invention belongs to the technical field of phased array radar, and specifically relates to a frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar. The present invention specifically includes a calibration transceiver switch module, an antenna calibration network module, a calibration receiver module, and a sum-difference channel receiver module, and by establishing a calibration timing and a calibration signal, the amplitude and phase in the transmitting and receiving channels are compensated and automatically calibrated. The automatic amplitude and phase calibration method of the phased array radar described in the present invention generates a receiving phase correction excitation signal during the receiving phase correction period and processes the received signal, sends the transmitting excitation signal to the calibration network during the transmitting phase correction period, and receives and processes the calibration signal coupled by the waveguide power divider by the calibration receiver, thereby completing the automatic amplitude and phase calibration, and improving the detection accuracy and reliability of the phased array radar in the process of object detection.

Description

Technical Field

[0001] The invention belongs to the technical field of phased array radars, and its IPC classification number is G01S13 / 02. The invention specifically relates to a frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radars. Background Art

[0002] Phased array radar is a device that monitors objects by changing the phase of radar waves to change the direction of the beam. In actual use, phased array radars are usually affected by multiple factors such as the external environment and internal device aging, which causes amplitude and phase errors in the transmitting and receiving channels, resulting in incorrect beam direction and ultimately low measurement accuracy.

[0003] Patent CN201510874578 provides a semi-closed loop coupled phased array channel amplitude and phase calibration device, which establishes multiple waveguide couplers and couples each waveguide coupler with a source phased array array. When the amplitude and phase information is fed back to the beam control distributor, the amplitude and phase are calibrated.

[0004] Patent CN201711380437 provides a phased array radar transmission channel cyclic calibration method, which establishes a feedback mechanism for amplitude-phase imbalance, compares the interpolation between the reference value and the actual value of the amplitude-phase, and repeatedly calculates the imbalance, thereby correcting the error of the amplitude of each channel.

[0005] However, the amplitude calibration methods described in the above patents all add additional error compensation processing devices on the basis of the original circuit structure design, which increases the overall complexity of each module in the control circuit, and the integration is not high. At the same time, it is not easy to repair when one of the modules is damaged. Therefore, it is urgent to introduce a frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar. Summary of the invention

[0006] In view of the above-mentioned problems, the present invention provides a frequency synthesis receiver based on automatic amplitude and phase calibration of phased array radar, which specifically includes a calibration transceiver switch module, an antenna calibration network module, a calibration receiver module, and a sum and difference channel receiver module. By establishing a calibration timing and a calibration signal, the amplitude and phase in the transmitting and receiving channels are compensated and automatically calibrated.

[0007] Preferably, a microwave component is installed in the frequency synthesizer receiver, and the microwave component generates a transmission excitation signal by performing power division on the input frequency-converted local oscillator signal and then up-converting the signal with the excitation waveform.

[0008] Preferably, the transmitting excitation signal is switched between an automatic receiving calibration state and a normal working signal state by setting a switch 1.

[0009] Preferably, in the normal working signal state, the state of switch 1 is "1", at this time, the excitation signal is output to the calibration transceiver switch module through the power amplifier circuit and the low-pass filter to form a transmitting excitation signal; in the automatic receiving calibration state, the state of switch 1 is "0", and the calibration transceiver switch module is set to the "transmit on" state, and the transmitting excitation signal is output to the antenna calibration network module through the calibration transceiver switch module.

[0010] Preferably, the calibration receiver module realizes signal switching between a normal working signal state and a transmission calibration state through switch 2.

[0011] Preferably, the calibration receiver module, in the normal working signal state, switch 2 is "1", at which time the invisible antenna is connected to realize invisible reception; in the transmission calibration state, switch 2 is "0", at which time the calibration receiver module receives the transmission calibration state signal from the antenna calibration network module.

[0012] Preferably, the signal of the transmitting calibration state is processed by the antenna calibration network module to form a calibration echo signal f R_JC .

[0013] Preferably, the calibration echo signal is limited and low noise amplified and then combined with the received local oscillator signal f R_Lo The down-conversion is completed in the image rejection mixer, and the intermediate frequency calibration signal f is formed after intermediate frequency filtering, amplification and AGC gain control. IF_JC , the specific calculation method is as follows:

[0014] f IF_JC =f R_JC -f R_Lo

[0015] Preferably, the sum and difference channel receiver module receives the echo f of the sum and difference channel. R_H and f R_C , after being limited and low noise amplified, it is combined with the received local oscillator signal f R_Lo The down-conversion is completed in the image rejection mixer, and the sum and difference intermediate frequency signals (f IF_H ,f IF_C ), the specific calculation method is as follows:

[0016] f IF_H =f R_H -f R_Lo

[0017] f IF_C =f R_C -f R_Lo

[0018] Preferably, the intermediate frequency calibration signal f IF_JC and the difference intermediate frequency signal (fIF_H ,f IF_C ) are uniformly output to the signal processor for processing.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The automatic amplitude and phase calibration method of the phased array radar described in the present invention generates a receiving phase correction excitation signal during the receiving phase correction period and processes the received signal, sends the transmitting excitation signal to the calibration network during the transmitting phase correction period, and the calibration receiver receives and processes the calibration signal coupled by the waveguide power divider, thereby completing the automatic amplitude and phase calibration. Compared with the calibration mode of the traditional phased array radar, the self-calibration method described in the present invention has a higher degree of integration. When the phased array radar equipment has a beam pointing deviation due to device aging or other reasons, or the antenna pattern index deteriorates, the radar system can effectively improve the pattern parameters of the phased array radar through the automatic amplitude and phase calibration function, thereby improving the detection accuracy and reliability of the phased array radar in the process of object detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the working principle block diagram of the frequency synthesis receiver. DETAILED DESCRIPTION

[0022] A frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar, specifically including a calibration transceiver switch module, an antenna calibration network module, a calibration receiver module, and a sum-difference channel receiver module, and by establishing a calibration timing and a calibration signal, the amplitude and phase in the transmitting and receiving channels are compensated and automatically calibrated. Specifically, Figure 1 As shown in the schematic diagram, the microwave component includes an up-conversion device for generating an excitation signal, an up-conversion device for generating a local oscillator signal, and a receiving front end.

[0023] In a preferred embodiment, the calibration timing determines and optimizes the timing relationship between frequencies by determining the frequency trigger delay time of the phased array radar itself, the delay time after the phased array radar receives feedback, etc., thereby performing amplitude and phase calibration based on timing.

[0024] In one embodiment, a microwave component is installed in the frequency synthesizer receiver, and the microwave component generates a transmission excitation signal by performing power division on the input frequency-converted local oscillator signal and then up-converting the signal with the excitation waveform.

[0025] In a preferred embodiment, the power divider divides the signal into a transmission excitation signal and a local oscillator signal, and the transmission excitation signal and the local oscillator signal are automatically calibrated for amplitude and phase respectively.

[0026] In one embodiment, the transmitting excitation signal is switched between an automatic receiving calibration state and a normal working signal state by setting a switch 1 .

[0027] In one embodiment, in the normal working signal state, the switch 1 state is "1", at this time, the excitation signal is output to the calibration transceiver switch module through the power amplifier circuit and the low-pass filter to form a transmission excitation signal; in the automatic reception calibration state, the switch 1 state is "0", the calibration transceiver switch module is set to the "transmit on" state, and the transmission excitation signal is output to the antenna calibration network module through the calibration transceiver switch module.

[0028] In one implementation, the calibration receiver module implements signal switching between a normal working signal state and a transmission calibration state through switch 2 .

[0029] In one embodiment, the calibration receiver module, switch 2 is "1" in the normal working signal state, at which time the invisible antenna is connected to realize invisible reception; in the transmission calibration state, switch 2 is "0", at which time the calibration receiver module receives the transmission calibration state signal from the antenna calibration network module.

[0030] In a preferred embodiment, the stealth antenna adds an auxiliary antenna to perform calculations based on the sidelobe stealth principle, update the radar radiation pattern, optimize the sidelobe interference problem of the radar antenna, and thus perform radiation phase calibration, wherein the calculation method is weighted processing of the interference signal, etc., to perform stealth reception.

[0031] In one embodiment, the signal of the transmitting calibration state is processed by the antenna calibration network module to form a calibration echo signal f R_JC .

[0032] In one embodiment, the calibration echo signal is limited and low noise amplified and then mixed with the received local oscillator signal f R_Lo The down-conversion is completed in the image rejection mixer, and the intermediate frequency calibration signal f is formed after intermediate frequency filtering, amplification and AGC gain control. IF_JC , the specific calculation method is as follows:

[0033] f IF_JC =f R_JC -f R_Lo

[0034] In one embodiment, the sum and difference channel receiver module receives the echo f of the sum and difference channel. R_H and f R_C , after being limited and low noise amplified, it is combined with the received local oscillator signal f R_Lo The down-conversion is completed in the image rejection mixer, and the sum and difference intermediate frequency signals (fIF_H ,f IF_C ), the specific calculation method is as follows:

[0035] f IF_H =f R_H -f R_Lo

[0036] f IF_C =f R_C -f R_Lo

[0037] In one embodiment, the intermediate frequency calibration signal f IF_JC and the difference intermediate frequency signal (f IF_H ,f IF_C ) are uniformly output to the signal processor for processing.

[0038] In a preferred embodiment, the working principle of the automatic amplitude and phase calibration of the phased array radar is to perform power division on the signal adjusted by the phase-locked loop through a microwave component, and divide it into an up-conversion design mode and a down-conversion design mode, and send the integrated two excitation signals to the calibration receiver module to transmit the excitation signal through the adjustment switch 1, and correspondingly transmit the excitation signal to the calibration receiver module and the difference channel receiver module for invisible reception, calibrate the received excitation signal through the antenna calibration network module, and perform reception, frequency conversion, amplification and other processing; generate a receiving phase correction excitation signal during the receiving phase correction period and process the received excitation signal, send the excitation signal to the antenna calibration network module during the transmitting phase correction period, and receive and process the calibration signal coupled by the waveguide power divider by the calibration receiver, thereby completing the automatic amplitude and phase calibration.

Claims

1. A frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar, characterized in that: Specifically, it includes a calibration transceiver switch module, an antenna calibration network module, a calibration receiver module, and a sum-difference channel receiver module, and by establishing a calibration sequence and a calibration signal, the amplitude and phase in the transmission and reception channels are compensated and automatically calibrated. The sum and difference channel receiver module receives the echo f of the sum and difference channel. R_H and f R_C , after being limited and low noise amplified, it is combined with the received local oscillator signal f R_Lo The down-conversion is completed in the image rejection mixer, and the sum and difference intermediate frequency signals (f IF_H ,f IF_C ), the specific calculation method is as follows: f IF_H =f R_H -f R_Lo (2) f IF_C =f R_C -f R_Lo (3)。 2. A frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar according to claim 1, characterized in that: The frequency synthesizer receiver is equipped with a microwave component, which generates a transmitting excitation signal by performing power division on the input frequency-converted local oscillator signal and then up-converting the signal with the excitation waveform.

3. A frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar according to claim 2, characterized in that: The transmitting excitation signal is switched between the automatic receiving calibration state and the normal working signal state by setting switch 1.

4. The frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar according to claim 3, characterized in that: In the normal working signal state, the switch 1 state is "1". At this time, the excitation signal is output to the calibration transceiver switch module through the power amplifier circuit and the low-pass filter to form a transmission excitation signal; in the automatic reception calibration state, the switch 1 state is "0", the calibration transceiver switch module is set to the "transmit on" state, and the transmission excitation signal is output to the antenna calibration network module through the calibration transceiver switch module.

5. The frequency synthesizer receiver based on phased array radar automatic amplitude and phase calibration according to claim 1, characterized in that: The calibration receiver module realizes signal switching between a normal working signal state and a transmission calibration state through switch 2.

6. A frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar according to claim 1 or 5, characterized in that: The calibration receiver module, in the normal working signal state, switch 2 is "1", at this time, the invisible antenna is connected to realize invisible reception; in the transmission calibration state, switch 2 is "0", at this time, the calibration receiver module receives the transmission calibration state signal from the antenna calibration network module.

7. The frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar according to claim 6, characterized in that: The signal of the transmitting calibration state is processed by the antenna calibration network module to form a calibration echo signal f R_JC .

8. The frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar according to claim 7, characterized in that: The calibration echo signal f R_JC After the limiting low noise amplifier and the receiving local oscillator signal f R_Lo The down-conversion is completed in the image rejection mixer, and the intermediate frequency calibration signal f is formed after intermediate frequency filtering, amplification and AGC gain control. IF_JC , the specific calculation method is as follows: f IF_JC =f R_JC -f R_Lo (1)。 9. The frequency synthesizer receiver based on automatic amplitude and phase calibration of phased array radar according to claim 8, characterized in that: The intermediate frequency calibration signal f IF_JC and the difference intermediate frequency signal (f IF_H ,f IF_C ) are uniformly output to the signal processor for processing.

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