A dual-band full-polarization integrated microwave radar system

Abstract

A dual-band full-polarization integrated microwave radar system belongs to the technical field of remote sensing detection. In view of the problems of high requirements for system integration and multiple requirements for working modes and functions, the present invention proposes a dual-band and full-polarization microwave radar system, which has the ability to work in a time-sharing or simultaneous manner in the C band and the Ku band; each band has two receiving channels, and can realize full-polarization microwave remote sensing detection. The internal calibration function of the system can perform internal status self-check and channel characteristic compensation, and is applicable to the application scenarios of high-precision, high-resolution, and multi-mode microwave remote sensing of land or ocean.

Description

Technical Field

[0001] The present invention relates to a dual-band fully polarized integrated microwave radar system, which can be applied to the development of radars on spacecraft or aircraft, and is suitable for application scenarios of high-precision, high-resolution, multi-mode microwave remote sensing detection of land or ocean, and belongs to the field of remote sensing detection. Background Art

[0002] In recent years, in order to build a remote sensing satellite system with global high resolution, high frequency and full coverage, remote sensing constellations composed of micro-satellites have shown a blowout trend. They provide global space big data in a low-cost, near-real-time, wide-coverage, high-resolution and fast-acquisition manner, leading the digital earth from the observation era to the new era of real-time earth. Driven by demand and supported by the development of other technologies, all countries have formulated micro-remote sensing payload research plans. Large-scale star clusters and constellation satellite systems adopt miniaturized designs, which have extremely high requirements for integration. How to achieve multi-functional and multi-mode payload design has become one of the hot areas in aerospace engineering. Summary of the invention

[0003] The technical problem solved by the present invention is: in view of the high requirements for system integration and multiple requirements for working modes and functions, a dual-band, fully polarized microwave radar system is proposed, which has the ability to work in C band and Ku band in time-sharing or simultaneously; further, each band in the system provided by the present invention has dual receiving channels, which can realize fully polarized microwave remote sensing detection. The system has an internal calibration function, which can perform internal state self-checking and channel characteristic compensation, and is suitable for application scenarios of high-precision, high-resolution, multi-mode microwave remote sensing of land or ocean.

[0004] The technical solution of the present invention is: a dual-band fully polarized integrated microwave radar system, including a control computer, a signal device, a microwave channel device and an antenna device; the control computer is connected to the front end of the signal device, the rear end of the signal device is connected to the microwave channel device, and the antenna device is installed at the output end of the microwave channel device;

[0005] The control computer is used for human-computer interaction to configure radar operating parameters and functions;

[0006] The signal device receives the command of the control computer; sends the control command to the microwave channel control unit, and after decoding, controls the working state of the components in the microwave channel; at the same time, the signal device directly sends the transmission, reception or internal calibration timing control signal to the microwave channel control unit using the TTL protocol, and controls the working timing of each component in the microwave channel after forwarding; at the same time, outputs the intermediate frequency transmission signal to the microwave channel device, and receives the intermediate frequency echo signal sent by the microwave channel device;

[0007] The microwave channel device receives the intermediate-frequency transmission signal, which is subjected to up-conversion and amplification processing in the transmission channel to form a radio-frequency transmission signal and is sent to the antenna unit. At the same time, the microwave channel device receives the radio-frequency echo signal output by the antenna unit, which is subjected to down-conversion and amplification processing by the low-noise amplifier and the receiver, and then converted into an intermediate-frequency echo signal and sent to the signal device for further processing. The control unit of the microwave channel device obtains the control instructions and timing control signals sent by the signal device, and forwards them to achieve internal component control. The antenna device is used to radiate the radio-frequency transmission signal output by the microwave channel device. At the same time, it receives the radio-frequency echo signal and transmits it to the microwave channel device.

[0008] Further, the signal device includes a signal board, a data board, a control board, and a power supply. The control board is respectively connected to the signal board and the data board. The power supply provides the required voltage and current for all boards.

[0009] The control board receives the instructions from the control computer, generates corresponding status control instructions and timing control signals, and sends them to the signal board and the data board respectively to ensure a unified working timing and status.

[0010] Further, the operating frequency band of the microwave channel device includes two frequency bands, C / Ku, and it can work independently or simultaneously.

[0011] Further, the microwave channel device includes a C-band transmission channel, a C-band low-noise amplifier module, a C-band calibrator, a C-band receiver, a Ku-band transmission channel, a Ku-band low-noise amplifier module, a Ku-band calibrator, a Ku-band receiver, a frequency source unit, a control unit, and a microwave power supply.

[0012] The C-band transmission channel includes an up-converter, a reference calibration coupler, a power amplifier, a transmission calibration coupler, a polarization switch, an H-polarization circulator, and a V-polarization circulator. The up-converter and the power amplifier are used to sequentially perform up-conversion and amplification processing on the intermediate-frequency transmission signal and then send it to the antenna unit. The reference calibrator coupler and the transmission calibrator coupler are used to extract the coupled calibration signal. The polarization switch is used for polarization channel selection and switching. The H-polarization circulator and the V-polarization circulator are used for separating the transmitted and received signals.

[0013] The C-band low-noise amplifier module is divided into two channels inside, including limiter X1, limiter X2, receive / calibration switch T1, receive / calibration switch T2, low-noise amplifier L1, and low-noise amplifier L2. Limiter X1 and limiter X2 are used to protect the low-noise amplifier from being burned by high power. The receive / calibration switch T1 and the receive / calibration switch T2 are used to switch the signal flow direction in the receive or calibration state. The low-noise amplifier L1 and the low-noise amplifier L2 are used to amplify the radar echo signal.

[0014] The C-band calibrator includes a reference calibration attenuator, a first power splitter, a receiving calibration attenuator, a second power splitter, a third power splitter, a fourth power splitter, switch T3, and switch T4, which are used to switch the signal flow direction in different calibration working states;

[0015] The Ku-band transmitting channel, the Ku-band low-noise amplifier module, and the Ku-band calibrator are respectively consistent with the C-band transmitting channel, the C-band low-noise amplifier module, and the C-band calibrator in technical implementation architecture;

[0016] The frequency source unit outputs two transmitting local oscillator signals with different frequencies, which are respectively provided to the upconverters of the C-band transmitting channel and the Ku-band transmitting channel to achieve the upconversion function; it outputs two C-band receiving local oscillator signals to the first C-band receiver and the second C-band receiver to achieve the downconversion function; it outputs two Ku-band receiving local oscillator signals to the first Ku-band receiver and the second Ku-band receiver to achieve the downconversion function;

[0017] The control unit is used to receive the status control instructions and timing control signals sent by the signal device, and send them to each component respectively to ensure a unified working timing and status;

[0018] The microwave power supply is used to convert the external 220V AC power supply into the required DC voltage inside and deliver it to each component in the microwave channel to ensure normal operation.

[0019] Furthermore, the microwave channel is an integrated cabinet product; an installation plate is fixedly installed inside the microwave channel cabinet in a suspended manner, and the components of the Ku and C bands are respectively located on the upper and lower sides of the installation plate; the control unit, the microwave power supply, and the frequency source are installed at the bottom of the cabinet; absorbing materials are pasted at the positions of the power amplifiers and low-noise amplifier modules in the cabinet to improve the electromagnetic environment.

[0020] According to the application method of a dual-band full-polarization integrated microwave radar system, it includes three working states: the transmitting process, the receiving process, and the internal calibration process; the signal flow directions of the three working states of the Ku-band transmitting process, the receiving process, and the internal calibration process are consistent with the corresponding working states of the C-band.

[0021] Furthermore, the transmitting process includes: when the C-band is working in the transmitting process, first, the control computer configures the radar working parameters, controls the signal device to send out the intermediate-frequency radar signal, enters the upconverter of the C-band transmitting channel, combines with the local oscillator signal input by the frequency source unit, upconverts to the working frequency signal, and after passing through the reference coupler, it is further amplified to the required power level by the power amplifier; after the amplified signal passes through the transmitting coupler, different polarization circulators are selected by the polarization switching switch according to needs, and finally the signal is fed to the antenna to achieve different polarization detection functions.

[0022] Further, the receiving process includes: when the C band is operating in the receiving process, the receive / calibration switch in the C-band low-noise amplifier module connects one end of the circulator, and switches T3 and T4 in the C-band calibrator respectively select to conduct and connect to two channels of the C-band low-noise amplifier module; the radar echo signal enters the orthomode coupler from the antenna and is divided into H or V polarization signals; the H polarization signal enters the C-band low-noise amplifier module after passing through the H polarization circulator, and after passing through the limiter X1, the receive / calibration switch T1, and the low-noise amplifier L1, it is input to the C-band calibrator; then it is gated by switch T3 and enters the C-band first receiver; after downconversion and amplification, it is input to the signal device for processing; the V polarization signal path is similar, and after passing through the V polarization circulator, the limiter X2, the receive / calibration switch T2, the low-noise amplifier L2, switch T4, and the C-band second receiver, it enters the signal device for processing.

[0023] Further, the internal calibration process includes: when the C band is operating in the calibration process, it includes three modes: reference calibration, receive calibration, and transmit calibration; during reference calibration, the signal after upconversion in the C-band transmit channel is coupled by the reference calibration coupler and enters the C-band calibrator; after passing through the first power divider, the reference calibration attenuator, and the fourth power divider, it is divided into two paths, and enters the C-band first receiver and the C-band second receiver respectively through switches T3 and T4 for frequency conversion and amplification; finally, it enters the signal device for processing; during receive calibration, the signal path sequentially passes through the C-band transmit channel upconverter, the reference coupler, the first power divider, the receive calibration attenuator, the second power divider, and then enters the C-band low-noise amplifier module; after that, the path is the same as the receiving process; during transmit calibration, the signal after passing through the power amplifier in the C-band transmit channel is coupled by the transmit coupler and enters the C-band calibrator, and after passing through the transmit calibration attenuator and the third power divider, it is divided into two paths, and enters the C-band first receiver and the C-band second receiver respectively through switches T3 and T4 for frequency conversion, filtering, and amplification; finally, it enters the signal device for processing; reference calibration, receive calibration, and transmit calibration work in a time-sharing manner.

[0024] A dual-band full-polarization integrated microwave radar device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the dual-band full-polarization integrated microwave radar method.

[0025] The advantages of the present invention compared with the prior art are as follows:

[0026] (1) The radar detection system of the present invention is integrally designed with two frequency bands and full-polarization detection capabilities. On the one hand, it reduces the total weight of the system and increases the proportion of the effective payload; on the other hand, it has more capabilities for obtaining target information.

[0027] (2) The radar detection system designed by the present invention can achieve time-division or simultaneous operation of different frequency bands under various working modes through corresponding control.

[0028] (3) The achievements of the present invention are particularly suitable for applications in scenarios with strict weight requirements such as small satellite earth observation; they can be extended to platforms such as unmanned aerial vehicles, radar vehicles, etc.

[0029] (4) The achievements of the present invention can be conveniently changed from dual polarization to a receiving dual-channel detection system by replacing the antenna; thus, more remote sensing detection functions such as interferometric mapping can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a technical implementation block diagram of a dual-band full-polarization integrated microwave radar system of the present invention

[0031] Figure 2 is a technical implementation block diagram of the C-band transmitting channel and the C-band antenna unit channel of the present invention

[0032] Figure 3 is a technical implementation block diagram of the C-band low-noise amplifier module of the present invention

[0033] Figure 4 is a technical implementation block diagram of the C-band calibrator of the present invention DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To better understand the above technical solutions, the technical solutions of the present application will be described in detail below through the drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present application are detailed descriptions of the technical solutions of the present application, rather than limitations on the technical solutions of the present application. Without conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0035] The following further details a dual-band full-polarization integrated microwave radar system provided by the embodiments of the present application in conjunction with the drawings of the specification. The specific implementation manners may include (as Figures 1 to 4 shown): a control computer, signal equipment, microwave channel equipment, and antenna equipment. The control computer is used for human-computer interaction and configuring the working parameters and functions of the radar. The signal equipment consists of a signal board, a data board, a control board, and a signal power supply; the microwave channel equipment includes two frequency bands, C / Ku, which can work independently or simultaneously, and mainly consists of a C-band transmitting channel, a C-band low-noise amplifier module, a C-band calibrator, a C-band receiver, a Ku-band transmitting channel, a Ku-band low-noise amplifier module, a Ku-band calibrator, a Ku-band receiver, a frequency source unit, a control unit, and a microwave power supply. The antenna equipment includes a C-band antenna unit and a Ku-band antenna unit.

[0036] Furthermore, the C-band transmission channel in the microwave channel device mainly includes an upconverter, a reference calibration coupler, a power amplifier, a transmission calibration coupler, a polarization switching switch, an H-polarization circulator, and a V-polarization circulator. The C-band low-noise amplifier module is divided into two channels, including limiter X1, limiter X2, receive / calibration switch T1, receive / calibration switch T2, low-noise amplifier L1, and low-noise amplifier L2. The C-band calibrator includes a reference calibration attenuator, a first power divider, a receive calibration attenuator, a second power divider, a third power divider, a fourth power divider, switch T3, and switch T4. The Ku-band transmission channel, Ku-band low-noise amplifier module, and Ku-band calibrator in the microwave channel device have the same technical implementation architecture as the C-band transmission channel, C-band low-noise amplifier module, and C-band calibrator, respectively.

[0037] Furthermore, the working process of the dual-band full-polarization integrated microwave radar system includes three working states: transmission process, reception process, and internal calibration process. When the C-band is in the transmission process, first, the control computer configures the radar working parameters, and the control signal device sends out an intermediate-frequency radar signal, which enters the upconverter in the C-band transmission channel. Combined with the local oscillator signal input by the frequency source unit, it is upconverted to the working frequency signal, and after passing through the reference coupler, it is further amplified to the required power level by the power amplifier. After the amplified signal passes through the transmission coupler, the polarization switching switch can select different polarization circulators according to needs, and finally, it is fed to the antenna to achieve different polarization detection functions.

[0038] When the C-band is in the reception process, the receive / calibration switch in the C-band low-noise amplifier module connects one end of the circulator, and switches T3 and T4 in the C-band calibrator respectively select to conduct and connect the two channels of the C-band low-noise amplifier module. The radar echo signal enters the orthomode coupler from the antenna and is divided into H or V polarization signals. The H-polarization signal passes through the H-polarization circulator and then enters the C-band low-noise amplifier module. After passing through limiter X1, receive / calibration switch T1, and low-noise amplifier L1, it is input to the C-band calibrator; then it is selected by switch T3 and enters the C-band first receiver; after downconversion and amplification, it is input to the signal device for processing. The V-polarization signal path is similar. After passing through the V-polarization circulator, limiter X2, receive / calibration switch T2, low-noise amplifier L2, switch T4, and the C-band second receiver, it enters the signal device for processing.

[0039] When the C-band is working in the calibration process, it mainly includes three modes: reference calibration, receive calibration, and transmit calibration. During reference calibration, the signal after up-conversion in the C-band transmit channel is coupled by a reference calibration coupler and enters the C-band calibrator; after passing through the first power divider, reference calibration attenuator, and fourth power divider, it is divided into two paths, which enter the first C-band receiver and the second C-band receiver through switches T3 and T4 respectively, and then are frequency-converted and amplified; finally, it enters the signal device for processing. During receive calibration, the signal path sequentially passes through the up-converter in the C-band transmit channel, reference coupler, first power divider, receive calibration attenuator, second power divider, and then enters the C-band low-noise amplifier module; after that, the path is the same as the receive process. During transmit calibration, the signal after the power amplifier in the C-band transmit channel is coupled by a transmit coupler and enters the C-band calibrator, and after passing through the transmit calibration attenuator and third power divider, it is divided into two paths, which enter the first C-band receiver and the second C-band receiver through switches T3 and T4 respectively, and then are frequency-converted, filtered, and amplified; finally, it enters the signal device for processing. Reference calibration, receive calibration, and transmit calibration can only work in a time-sharing manner.

[0040] The signal flow directions of the three working states of the Ku-band transmit process, receive process, and internal calibration process are the same as those of the corresponding working states of the C-band.

[0041] Furthermore, the frequency source unit in the microwave channel outputs two transmit local oscillator signals with different frequency points, which are respectively provided to the up-converter in the C-band transmit channel and the up-converter in the Ku-band transmit channel to achieve the up-conversion function; it outputs two C-band receive local oscillator signals to the first C-band receiver and the second C-band receiver to achieve the down-conversion function; it outputs two Ku-band receive local oscillator signals to the first Ku-band receiver and the second Ku-band receiver to achieve the down-conversion function.

[0042] Furthermore, the signal device outputs a total of two intermediate-frequency transmit signals and receives four intermediate-frequency echo signals, and the corresponding frequency points can be determined as needed. The signal device uses the SPI transmission protocol to send control instructions to the microwave channel control unit, and after decoding, it controls the working states of the internal components in the microwave channel. At the same time, the signal device directly sends transmit and receive timing control signals to the microwave channel control unit using the TTL protocol, and after forwarding, it controls the working timings of the internal components in the microwave channel.

[0043] Furthermore, the microwave power supply mainly converts the external 220V AC power supply into the DC voltage required internally and delivers it to the internal components in the microwave channel to ensure normal operation. The signal power supply converts the external 220V into the working voltage required by the signal device.

[0044] Furthermore, radar dual-band detection can be achieved through system configuration. The Ku-band and C-band can work independently or simultaneously, and the corresponding radar parameters, etc. can be configured independently.

[0045] Furthermore, the C-band or Ku-band microwave channel can be replaced according to actual needs to achieve other dual-band detection combinations.

[0046] Furthermore, full-polarization radar detection can be achieved. Both the Ku-band and C-band can obtain full-polarization radar detection functions by keeping two receiving links working simultaneously; the HH, HV, VH, and VV full-polarization radar detection functions can be achieved through the polarization switching switch.

[0047] The present invention includes an internal calibration function. Both the Ku band and the C band can work in time-sharing manner through reference calibration, receiving calibration and transmitting calibration to realize a complete internal calibration function, thereby testing the stability of the system hardware and compensating for the channel error.

[0048] Furthermore, by removing the orthogonal mode coupler in the antenna device and changing one circularly polarized antenna into two conventional antennas, which are respectively connected to two circulators, a dual-channel receiving function can be obtained, which can be used in microwave interferometric terrain mapping, ground target detection and other application scenarios that require dual channels.

[0049] Furthermore, the microwave channel is an integrated cabinet product. A mounting plate is suspended and fixed inside the cabinet, and the components of the Ku and C frequency bands are located on the upper and lower sides of the mounting plate respectively. The control unit, microwave power supply and frequency source are installed at the bottom of the cabinet. Absorbing materials are pasted on the power amplifier, low noise amplifier module and other positions in the cabinet to improve the electromagnetic environment.

[0050] The basic working principle of the present invention includes a transmitting process, a receiving process, and an internal calibration process. During the transmitting process, the radar system operating frequency, bandwidth, signal form, pulse width and other working parameters are configured by operating the signal device on the computer to generate a radar baseband signal that meets the requirements; the signal enters the microwave channel device through a cable connection, and is transmitted by the antenna after up-conversion and amplification. During the receiving process, the signal device is controlled on the computer to configure the receiving gain, receiving window width, channel selection and other working parameters. After the antenna receives the radar echo signal, it is introduced into the microwave channel device, and after down-conversion and amplification, it is transmitted to the signal device for sampling and storage. The internal calibration process includes reference calibration, receiving calibration and transmitting calibration. The radar signal parameters and microwave channel devices are configured by operating the signal device on the computer, especially the switch in the calibrator, and the signal flow path is selected to realize the internal calibration function.

[0051] In the solution provided in the embodiment of the present application, Figure 1As shown in the figure, an embodiment of the present invention provides a design of a dual-band full-polarization integrated microwave radar system, which mainly includes: a control computer 1, a signal device 2, a microwave channel device 3, and an antenna device 4. The control computer 1 is used for human-computer interaction and generates initial system control instructions to be sent to the control board 6 in the signal device 2; and then the control board 6 generates secondary control instructions and transmits them to the signal board 5, the data board 7, and the control unit 19 in the microwave channel device 3 respectively. After obtaining the instructions, the control unit 19 further generates tertiary instructions for each component in the microwave channel device 3.

[0052] In an optional embodiment, from the control computer 1 to the control board 6, USB to serial port RS232 communication is adopted; from the control board 6 to the signal board 5 and the data board 7, internal bus communication is adopted; from the control board 6 to the control unit 19, RS422 differential signals are used for communication, and the SPI protocol is used for data packet transmission.

[0053] The signal board 5 generates intermediate-frequency radar signals with timing characteristics according to the control instructions and transmits them to the C-band transmitting channel 9 and the Ku-band transmitting channel 14 respectively. Taking the C-band transmission as an example, the intermediate-frequency radar signal passes through upconversion 31, reference calibration coupler 32, power amplifier 33, transmit calibration coupler 34, polarization switch 35, H-polarization circulator 36 or V-polarization circulator 37 in sequence, and is transmitted by the C-band antenna unit 21. The Ku-band transmission process is similar.

[0054] Furthermore, in an optional embodiment, the intermediate-frequency radar signal can be selected with a frequency of 1.2 GHz, the C-band local oscillator signal for transmission can be selected as 4.2 GHz, and after mixing, a radar transmission signal with a center frequency of 5.4 GHz is realized; the Ku-band local oscillator signal for transmission can be selected as 12 GHz, and after mixing, a radar transmission signal with a center frequency of 13.2 GHz is realized. The power amplifier can be selected according to actual needs. In the case of airborne application scenarios, a solid-state power amplifier can be selected, with a peak power output of 200 W; in the case of spaceborne applications, a traveling-wave tube amplifier can be selected, with a peak power output of more than 1000 W.

[0055] Also taking the C-band as an example, when working in the receiving process, after the circularly polarized antenna 39 receives the radar echo signal, it is divided into two paths of H / V through the orthomode coupler 38 and enters the H-polarization circulator 36 and the V-polarization circulator 37 respectively, so as to be separated into two independent receiving paths. As Figure 2 shown, taking the H-polarization as an example, the signal output by the H-polarization circulator 36 passes through the limiter X151, the receive / calibration switch T1 53, and enters the low-noise amplifier L1 55 to complete the amplification function; then after passing through the switch T4 68 in the C-band calibrator 12 and being frequency-converted and amplified by the C-band first receiver 15, it enters the signal device 2 for sampling and processing. The Ku-band receiving process is similar.

[0056] In an optional embodiment, the amplification gains of the low-noise amplifier L1 55 and the low-noise amplifier L2 56 are selected to be above 30 dB, so as to achieve a lower link cascade noise figure. The gain of the C-band first receiver 15 is above 60 dB to achieve an overall link gain above 90 dB. The C-band local oscillator signal for reception can be selected as 4.8 GHz, and after mixing, an intermediate-frequency echo signal with a center frequency of 0.6 GHz is achieved; the Ku-band local oscillator signal for transmission can be selected as 12.6 GHz, and after mixing, an intermediate-frequency echo signal with a center frequency of 0.6 GHz is also achieved.

[0057] The internal calibration process includes reference calibration, reception calibration, and transmission calibration, and the three calibrations have different signal flow paths. The purpose of reference calibration is to obtain the link channel characteristic function of the link after the upconverter and through the receiver. When performing reception calibration, the link channel characteristic function of the link through the low-noise amplifier and the receiver is obtained. Transmission calibration is to obtain the link channel characteristic function of the link through the power amplifier and the receiver. As Figure 3 shown, taking the C-band calibration process as an example, during reference calibration, the radar signal after upconversion in the C-band transmission channel 9 is coupled by the reference calibration coupler 32 and enters the C-band calibrator 12; after passing through the first power divider 61, the reference calibration attenuator 63, and the fourth power divider 67, it is divided into two paths, and enters the C-band first receiver 10 and the C-band second receiver 11 through the switches T3 68 and T4 69 respectively, and then undergoes frequency conversion and amplification; finally, it enters the signal device 2 for processing. When performing reception calibration, the signal after the upconverter is also selected, and the power is balanced through the first power divider 61 and the reception calibration attenuator 62, and then divided into two paths through the first power divider 64 and enters the C-band low-noise amplifier module 13 respectively. At this time, both the receive / calibration switch T1 53 and the receive / calibration switch T2 54 select the reception calibration function end. The two paths of signals return to the C-band calibrator 12, and after being introduced into the receiver, they enter the signal device 2 for sampling and processing. When performing transmission calibration, the signal after the power amplifier 33 is led out by the transmission calibration coupler 34, and the level is registered through the transmission calibration attenuator, and then divided into two paths by the third power divider 66, and then enter the receiver and the signal device respectively to complete sampling. The internal calibration process in the Ku band is similar.

[0058] The transmission process and the reception process are alternately carried out in sequence, and the corresponding time window width, etc. need to be calculated according to actual needs. In an optional embodiment, taking the case where the aircraft is at an altitude of 3 km from the ground, the beam incident angle is 60°, and the beam width is 14° as an example, the transmission window width can be set to 20 us, and the reception window width can be set to 50 us. The transmission and reception work alternately for 1 minute, and an internal calibration is performed once, with 10 pulses for each of the reference calibration, reception calibration, and transmission calibration.

[0059] This application provides a computer-readable storage medium storing computer instructions that, when run on a computer, cause the computer to execute Figure 1 the method described above.

[0060] Those skilled in the art will understand that the embodiments of this application may be provided as a method, a system, or a computer program product. Therefore, this application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, this application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) containing computer-usable program code.

[0061] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the specified functions in Figure 1 one or more of the flows Figure 1 or blocks or combinations of blocks.

[0062] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the specified functions in Figure 1 one or more of the flows Figure 1 or blocks or combinations of blocks.

[0063] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are performed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the specified functions in Figure 1 one or more of the flows Figure 1 or blocks or combinations of blocks.

[0064] In summary, the dual-band fully polarized integrated microwave radar system proposed by the present invention has the detection capabilities of high and low frequency bands, and can fully exploit the target scene information. It can also change the frequency band by replacing microwave devices and antennas as needed while keeping the main structure unchanged. At the same time, the radar system proposed by the present invention can achieve the receiving dual-channel working function by replacing the antenna, and can be used in scenarios such as microwave interferometric terrain mapping and ground target detection.

[0065] On the other hand, the present invention proposes a dual-band fully polarized integrated microwave radar system. By designing the microwave channel device and signal device with dual-band and dual-channel fusion, the high integration of the radar system is achieved, which can reduce the overall system weight, improve the composite working ability of electronic devices, expand the working mode, and is suitable for applications on spacecraft and aircraft, especially suitable for applications on unmanned aerial vehicles and small satellites.

[0066] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalent technologies, this application also intends to include these modifications and variations.

[0067] The content not described in detail in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. A dual-band full-polarization integrated microwave radar system, characterized in that: It includes a control computer, a signal device, a microwave channel device, and an antenna device; the control computer is connected to the front end of the signal device, the rear end of the signal device is connected to the microwave channel device, and the antenna device is installed at the output end of the microwave channel device; The control computer is used for human-computer interaction and configuration of radar operating parameters and functions; The signal device receives instructions from the control computer; sends control instructions to the microwave channel control unit, and after decoding, controls the operating states of internal components in the microwave channel; at the same time, the signal device directly sends transmit, receive, or internal calibration timing control signals to the microwave channel control unit using the TTL protocol, and after forwarding, controls the operating timing of each internal component in the microwave channel; at the same time, it outputs an intermediate-frequency transmit signal to the microwave channel device and receives the intermediate-frequency echo signal sent by the microwave channel device; The microwave channel device receives the intermediate-frequency transmit signal, and after up-conversion and amplification processing in the transmit channel, forms a radio-frequency transmit signal and sends it to the antenna unit; at the same time, the microwave channel device receives the radio-frequency echo signal output by the antenna unit, and after low-noise amplification and down-conversion and amplification processing by the receiver, converts it into an intermediate-frequency echo signal and sends it to the signal device for further processing; the control unit of the microwave channel device obtains the control instructions and timing control signals sent by the signal device, and after forwarding, realizes internal component control; the antenna device is used to radiate the radio-frequency transmit signal output by the microwave channel device; at the same time, it receives the radio-frequency echo signal and transmits it to the microwave channel device; The operating frequency band of the microwave channel device includes two frequency bands, C / Ku, which can work independently or simultaneously; The microwave channel device includes a C-band transmit channel, a C-band low-noise amplifier module, a C-band calibrator, a C-band receiver, a Ku-band transmit channel, a Ku-band low-noise amplifier module, a Ku-band calibrator, a Ku-band receiver, a frequency source unit, a control unit, and a microwave power supply; The C-band transmit channel includes an up-converter, a reference calibration coupler, a power amplifier, a transmit calibration coupler, a polarization switching switch, an H-polarization circulator, and a V-polarization circulator. The up-converter and the power amplifier are used to sequentially perform up-conversion and amplification processing on the intermediate-frequency transmit signal and then send it to the antenna unit; the reference calibrator coupler and the transmit calibrator coupler are used to extract coupled calibration signals; the polarization switching switch is used for polarization channel selection and switching; the H-polarization circulator and the V-polarization circulator are used for signal separation of transmission and reception; The C-band low-noise amplifier module is divided into two channels inside, including limiter X1, limiter X2, receive / calibration switch T1, receive / calibration switch T2, low-noise amplifier L1, and low-noise amplifier L2. Limiter X1 and limiter X2 are used to protect the low-noise amplifier from being burned by high power; receive / calibration switch T1 and receive / calibration switch T2 are used for signal flow switching in the receive or calibration state; low-noise amplifier L1 and low-noise amplifier L2 are used for amplification of radar echo signals; The C-band calibrator includes a reference calibration attenuator, a first power divider, a receive calibration attenuator, a second power divider, a third power divider, a fourth power divider, switch T3, and switch T4, which are used to switch the signal flow direction in different calibration working states; The technical implementation architectures of the Ku-band transmit channel, the Ku-band low-noise amplifier module, and the Ku-band calibrator are the same as those of the C-band transmit channel, the C-band low-noise amplifier module, and the C-band calibrator respectively; The frequency source unit outputs two transmit local oscillator signals with different frequencies, which are respectively provided to the upconverters of the C-band transmit channel and the Ku-band transmit channel to implement the upconversion function; it outputs two C-band receive local oscillator signals to the first C-band receiver and the second C-band receiver to implement the downconversion function; it outputs two Ku-band receive local oscillator signals to the first Ku-band receiver and the second Ku-band receiver to implement the downconversion function; The control unit is used to receive the status control instructions and timing control signals sent by the signal device, and send them to each component respectively to ensure a unified working timing and status; The microwave power supply is used to convert the external AC power supply into the required DC voltage inside and deliver it to each component in the microwave channel to ensure normal operation.

2. The dual-band full-polarization integrated microwave radar system according to claim 1, characterized in that: The signal device includes a signal board, a data board, a control board, and a power supply; the control board is respectively connected to the signal board and the data board; the power supply provides the required voltage and current for all boards; The control board receives the instructions from the control computer, generates corresponding status control instructions and timing control signals, and sends them to the signal board and the data board respectively to ensure a unified working timing and status.

3. A dual-band full-polarization integrated microwave radar system according to claim 1, characterized in that: The microwave channel is an integrated cabinet product; a mounting plate is fixedly installed inside the microwave channel cabinet in a suspended manner, and the components of the Ku and C bands are respectively located on the upper and lower sides of the mounting plate; the control unit, the microwave power supply, and the frequency source are installed at the bottom of the cabinet; wave-absorbing materials are pasted at the positions of the power amplifiers and low-noise amplifier modules in the cabinet to improve the electromagnetic environment.

4. The application method of a dual-band full-polarization integrated microwave radar system according to claim 1, characterized in that, It includes three working states: the transmit process, the receive process, and the internal calibration process; the signal flow directions of the three working states of the Ku-band transmit process, the receive process, and the internal calibration process are the same as those of the corresponding working states of the C-band; The internal calibration process includes: when the C band is operating in the calibration process, it includes three modes: reference calibration, receive calibration, and transmit calibration; during reference calibration, the signal after upconversion in the C-band transmit channel is coupled by a reference calibration coupler and enters the C-band calibrator; after passing through the first power divider, reference calibration attenuator, and fourth power divider, it is divided into two paths, and enters the first C-band receiver and the second C-band receiver through switches T3 and T4 respectively, and then undergoes frequency conversion and amplification; finally, it enters the signal device for processing; during receive calibration, the signal path sequentially passes through the upconverter in the C-band transmit channel, reference coupler, first power divider, receive calibration attenuator, second power divider, and then enters the C-band low-noise amplifier module; after that, the path is the same as the receive process; during transmit calibration, the signal after passing through the power amplifier in the C-band transmit channel is coupled by a transmit coupler and enters the C-band calibrator, and after passing through the transmit calibration attenuator and third power divider, it is divided into two paths, and enters the first C-band receiver and the second C-band receiver through switches T3 and T4 respectively, and then undergoes frequency conversion, filtering, and amplification; finally, it enters the signal device for processing; reference calibration, receive calibration, and transmit calibration work in a time-sharing manner.

5. The method according to claim 4, wherein The transmit process includes: when the C band is operating in the transmit process, first, the control computer configures the radar operating parameters, controls the signal device to send out an intermediate-frequency radar signal, enters the upconverter in the C-band transmit channel, combines with the local oscillator signal input by the frequency source unit, upconverts to the operating frequency signal, and is further amplified to the required power level through a reference coupler and then a power amplifier; after the amplified signal passes through the transmit coupler, different polarization circulators are selected by the polarization switching switch according to needs, and finally, it is fed to the antenna to achieve different polarization detection functions.

6. The method according to claim 4, wherein The receive process includes: when the C band is operating in the receive process, the receive / calibration switch in the C-band low-noise amplifier module connects one end of the circulator, and switches T3 and T4 in the C-band calibrator respectively select to conduct and connect the two channels of the C-band low-noise amplifier module; the radar echo signal enters the quadrature-mode coupler from the antenna and is divided into H or V polarization signals; the H polarization signal passes through the H polarization circulator and enters the C-band low-noise amplifier module, and after passing through the limiter X1, receive / calibration switch T1, and low-noise amplifier L1, it is input to the C-band calibrator; then it is selected by switch T3 and enters the first C-band receiver; after downconversion and amplification, it is input to the signal device for processing; the V polarization signal path is similar, and after passing through the V polarization circulator, limiter X2, receive / calibration switch T2, low-noise amplifier L2, switch T4, and the second C-band receiver, it enters the signal device for processing.

7. A dual-band full-polarization integrated microwave radar device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the steps of the method according to any one of claims 4 to 6.

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