A single-bit synthetic aperture radar device, system and imaging method thereof

Abstract

This invention discloses a single-bit synthetic aperture radar device, system, and imaging method. The device includes a radio frequency transceiver, a digital board, a receiving antenna, and a transmitting antenna. The digital board generates a radio frequency signal and outputs it to the radio frequency transceiver. The radio frequency transceiver is used to mix a frequency-doubled signal obtained from the radio frequency signal with a first single-frequency carrier signal to obtain a first mixed signal, and processes the first mixed signal to obtain a transmitted signal. It is also used to mix the frequency-doubled signal with a second single-frequency carrier signal to obtain a second mixed signal, and to mix the second mixed signal with an echo signal to obtain a third mixed signal. Furthermore, it is used to demodulate the third mixed signal to obtain a first intermediate frequency (IF) signal and a second IF signal. The digital board is also used to perform single-bit sampling of the first IF signal and the second IF signal. Thus, in this invention, the digital board can perform single-bit sampling of the IF signal, thereby achieving the real-time imaging requirements of the radar imaging system.

Description

Technical Field

[0001] This invention relates to the field of radar technology, and in particular to a single-bit synthetic aperture radar device, system and imaging method thereof. Background Technology

[0002] Linear Frequency Modulated Continuous Wave (LFMCW) synthetic aperture radar (SAR) boasts advantages such as small size, light weight, and low power consumption. In recent years, the unmanned aerial vehicle (UAV) industry has developed rapidly. Mounting miniaturized SAR systems on small and medium-sized UAVs can greatly leverage their respective advantages. Such UAV-borne miniature SAR systems are typically used for low-altitude remote sensing operations, enabling convenient and rapid acquisition of high-resolution SAR images, offering far greater convenience and flexibility than traditional spaceborne and airborne SAR.

[0003] However, traditional radar imaging systems typically use high-speed ADCs to quantize echo signals into 8-bit or 16-bit data, resulting in large data acquisition volumes and high data rates, which are not conducive to real-time data processing and make it difficult for radar imaging systems to meet real-time imaging requirements.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a single-bit synthetic aperture radar device, system and imaging method, so as to solve the problem that traditional radar imaging systems cannot meet the requirements of real-time imaging.

[0006] The technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a single-bit synthetic aperture radar device, comprising: a radio frequency transceiver, a digital board, a receiving antenna, and a transmitting antenna; wherein...

[0008] The digital board is connected to the radio frequency transceiver, and the digital board is used to generate radio frequency signals and output them to the radio frequency transceiver.

[0009] The radio frequency transceiver is configured to mix a frequency-doubled signal obtained from a radio frequency signal with a first single-frequency carrier signal to obtain a first mixed signal, and process the first mixed signal to obtain a transmitted signal. It is also configured to mix the frequency-doubled signal with a second single-frequency carrier signal to obtain a second mixed signal, and to mix the second mixed signal with an echo signal to obtain a third mixed signal. Furthermore, it is configured to demodulate the third mixed signal to obtain a first intermediate frequency signal and a second intermediate frequency signal; wherein the frequency of the third mixed signal is greater than the frequency of the transmitted signal.

[0010] The digital board is also used to perform single-bit sampling on the first intermediate frequency signal and the second intermediate frequency signal;

[0011] The transmitting antenna is connected to the radio frequency transceiver, and the transmitting antenna is used to transmit the transmitting signal.

[0012] The receiving antenna is connected to the radio frequency transceiver and is used to receive echo signals.

[0013] In a further embodiment of the present invention, the single-bit synthetic aperture radar device also includes a power supply board; the power supply board is connected to the radio frequency transceiver and the digital board respectively, and the power supply board is used to supply power to the radio frequency transceiver and the digital board.

[0014] In a further embodiment of the present invention, the radio frequency transceiver includes a single-bit ADC; the single-bit ADC is connected to the radio frequency transceiver, and the single-bit ADC is used to perform single-bit sampling on the first intermediate frequency signal and the second intermediate frequency signal.

[0015] In a further embodiment of the present invention, the radio frequency transceiver includes: a frequency multiplication signal generation unit, a first single-frequency carrier signal generation unit, a second single-frequency carrier signal generation unit, a first mixing unit, a second mixing unit, a third mixing unit, and an IQ demodulation unit; wherein,

[0016] The frequency multiplication signal generation unit is connected to the digital board, and the frequency multiplication signal generation unit is used to process the radio frequency signal to obtain the frequency multiplication signal;

[0017] The first single-frequency carrier signal generation unit is connected to the first mixing unit and the digital board respectively. The first single-frequency carrier signal generation unit is used to process the single-frequency signal to obtain the first single-frequency carrier signal and the clock signal.

[0018] The second single-frequency carrier signal generation unit is connected to the second mixing unit, and the second single-frequency carrier signal generation unit is used to process the single-frequency signal to obtain the second single-frequency carrier signal;

[0019] The first mixing unit is connected to the frequency multiplication signal generation unit and the first single-frequency carrier signal generation unit respectively. The first mixing unit is used to mix the frequency multiplication signal and the first single-frequency carrier signal to obtain the transmitted signal.

[0020] The second mixing unit is connected to the frequency multiplication signal generation unit and the second single-frequency carrier signal generation unit respectively. The second mixing unit is used to perform frequency multiplication processing on the frequency multiplication signal and the second single-frequency carrier signal to obtain a second mixed signal.

[0021] The third mixing unit is connected to the second mixing unit, and the third mixing unit is used to perform mixing processing on the echo signal and the second mixing signal to obtain a third mixing signal;

[0022] The IQ demodulation unit is connected to the third mixing unit and the digital board respectively. The IQ demodulation unit is used to demodulate the third mixing signal to obtain the first intermediate frequency signal and the second intermediate frequency signal.

[0023] In a further embodiment of the present invention, the first single-frequency carrier signal generation unit includes: a first phase-locked loop, a first low-pass filter, a first frequency multiplier, a first intermediate power amplifier, a first band-pass filter, a second intermediate power amplifier, and a second low-pass filter; wherein,

[0024] The input terminal of the first phase-locked loop is connected to a single-frequency signal, and the output terminal of the first phase-locked loop is connected to the input terminal of the first low-pass filter and the input terminal of the second intermediate power amplifier, respectively.

[0025] The output of the first low-pass filter is connected to the input of the first frequency multiplier.

[0026] The output terminal of the first frequency multiplier is connected to the input terminal of the first intermediate power amplifier;

[0027] The output terminal of the first intermediate power amplifier is connected to the input terminal of the first bandpass filter, and the output terminal of the first bandpass filter is connected to the first mixer unit;

[0028] The output terminal of the second intermediate power amplifier is connected to the input terminal of the first low-pass filter, and the output terminal of the low-pass filter is connected to the digital board;

[0029] The second single-frequency carrier signal generation unit includes: a second phase-locked loop, a third low-pass filter, a fixed attenuator, a second frequency multiplier, a third intermediate power amplifier, and a second band-pass filter; wherein,

[0030] The input terminal of the second phase-locked loop is connected to a single-frequency signal, and the output terminal of the second phase-locked loop is connected to the input terminal of the third low-pass filter;

[0031] The output of the third low-pass filter is connected to the input of the fixed attenuator, and the output of the fixed attenuator is connected to the input of the second frequency multiplier.

[0032] The output of the second frequency multiplier is connected to the input of the third intermediate power amplifier;

[0033] The output of the third intermediate power amplifier is connected to the input of the second bandpass filter, and the output of the second bandpass filter is connected to the second mixer unit.

[0034] In a further embodiment of the present invention, the first mixing unit includes: a first mixer, a third bandpass filter, a fourth intermediate power amplifier, a digitally controlled attenuator, and a radio frequency power amplifier; wherein,

[0035] The input terminal of the first mixer is connected to the output terminal of the frequency multiplication signal generation unit and the output terminal of the first single-frequency carrier signal generation unit, respectively, and the output terminal of the first mixer is connected to the input terminal of the third bandpass filter;

[0036] The output of the third bandpass filter is connected to the input of the fourth intermediate power amplifier, and the output of the intermediate power amplifier is connected to the input of the digitally controlled attenuator.

[0037] The output terminal of the digitally controlled attenuator is connected to the input terminal of the radio frequency power amplifier, and the output terminal of the radio frequency power amplifier is connected to the transmitting antenna.

[0038] The second mixing unit includes: a second mixer, a fourth bandpass filter, and a fifth intermediate power amplifier; wherein,

[0039] The input terminal of the second mixer is connected to the output terminal of the frequency multiplication signal generation unit and the output terminal of the second single-frequency carrier signal generation unit, respectively, and the output terminal of the second mixer is connected to the input terminal of the fourth bandpass filter;

[0040] The output of the fourth bandpass filter is connected to the input of the fifth intermediate power amplifier;

[0041] The output terminal of the fifth intermediate power amplifier is connected to the input terminal of the third mixer unit;

[0042] The third mixing unit includes: a third mixer, a low-noise amplifier, a fifth bandpass filter, a sixth intermediate power amplifier, a second digitally controlled attenuator, and a seventh intermediate power amplifier; wherein...

[0043] The input terminal of the third mixer is connected to the output terminal of the second mixer unit and the output terminal of the low-noise amplifier, respectively, and the output terminal of the third mixer is connected to the input terminal of the fifth bandpass filter.

[0044] The input terminal of the low-noise amplifier is connected to the receiving antenna;

[0045] The output of the fifth bandpass filter is connected to the input of the sixth intermediate power amplifier, and the output of the sixth intermediate power amplifier is connected to the input of the second digitally controlled attenuator.

[0046] The output terminal of the second digitally controlled attenuator is connected to the input terminal of the seventh intermediate power amplifier, and the output terminal of the seventh intermediate power amplifier is connected to the IQ demodulation unit.

[0047] In a further embodiment of the present invention, the IQ demodulation unit includes: a fourth mixer, a sixth bandpass filter, a first operational amplifier, a seventh bandpass filter, a fifth mixer, an eighth bandpass filter, a second operational amplifier, and a ninth bandpass filter; wherein,

[0048] The input terminal of the fifth mixer is connected to the output terminal of the third mixer unit, and the output terminal of the fifth mixer is connected to the output terminal of the sixth bandpass filter.

[0049] The output of the sixth bandpass filter is connected to the input of the first operational amplifier;

[0050] The output terminal of the first operational amplifier is connected to the input terminal of the seventh bandpass filter, and the output terminal of the seventh bandpass filter is connected to the digital board;

[0051] The input terminal of the fifth mixer is connected to the output terminal of the third mixer unit, and the output terminal of the fifth mixer is connected to the input terminal of the eighth bandpass filter.

[0052] The output of the eighth bandpass filter is connected to the input of the second operational amplifier, and the output of the second operational amplifier is connected to the input of the ninth bandpass filter.

[0053] The output of the ninth bandpass filter is connected to the digital board.

[0054] In a further embodiment of the present invention, the frequency multiplication signal generation unit is a filter amplification frequency multiplication group, and the radio frequency signal is generated by the filter amplification frequency multiplication group.

[0055] Secondly, the present invention also provides a single-bit synthetic aperture radar system, which includes a host computer and a single-bit synthetic aperture radar device as described above, wherein the digital board is connected to the host computer, and the host computer is used to obtain image data based on the first intermediate frequency signal and the second intermediate frequency signal.

[0056] Thirdly, the present invention also provides an imaging method based on the above-described single-bit synthetic aperture radar system, comprising:

[0057] The control digital board generates radio frequency signals and single-frequency signals;

[0058] The frequency-multiplied signal is obtained from the radio frequency signal, and the first single-frequency carrier signal and the second single-frequency carrier signal are obtained from the single-frequency signal.

[0059] The frequency multiplier signal is mixed with the first single-frequency carrier signal to obtain the first mixed signal, and the first mixed signal is processed to obtain the transmitted signal;

[0060] The frequency multiplier signal is mixed with the second single-frequency carrier signal to obtain a second mixed signal, and the second mixed signal is mixed with the echo signal to obtain a third mixed signal.

[0061] The third mixing signal is demodulated to obtain a first intermediate frequency signal and a second intermediate frequency signal; wherein the frequency of the third mixing signal is greater than the frequency of the transmitted signal;

[0062] Radar data is obtained by sampling the first intermediate frequency signal and the second intermediate frequency signal, and image data is obtained based on the radar data.

[0063] This invention provides a single-bit synthetic aperture radar device, system, and imaging method. The device includes: a radio frequency transceiver, a digital board, a receiving antenna, and a transmitting antenna. The digital board is connected to the radio frequency transceiver and is used to generate radio frequency signals and output them to the radio frequency transceiver. The radio frequency transceiver is used to mix a frequency-doubled signal obtained from the radio frequency signal with a first single-frequency carrier signal to obtain a first mixed signal, and to process the first mixed signal to obtain a transmitted signal. It is also used to mix the frequency-doubled signal with a second single-frequency carrier signal to obtain a second mixed signal, and to mix the second mixed signal with an echo signal to obtain a third mixed signal. Furthermore, it is used to demodulate the third mixed signal to obtain a first intermediate frequency signal and a second intermediate frequency signal. The frequency of the third mixed signal is greater than the frequency of the transmitted signal. The digital board is also used to perform single-bit sampling of the first and second intermediate frequency signals. Thus, the first and second intermediate frequency signals output by the radio frequency transceiver in this invention have frequency offsets, which can suppress odd harmonics introduced outside the intermediate frequency signal during single-bit sampling. This allows the digital board to perform single-bit sampling of the first and second intermediate frequency signals, resulting in a small amount of data collected and a low data rate, which is beneficial for real-time data processing and can thus meet the real-time imaging requirements of the radar imaging system. Attached Figure Description

[0064] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0065] Figure 1 This is a schematic diagram of the single-bit synthetic aperture radar system in this invention.

[0066] Figure 2 This is a schematic diagram of the radio frequency transceiver in this invention.

[0067] Figure 3 This is a flowchart illustrating the single-bit synthetic aperture radar imaging method of this invention.

[0068] The labels in the attached diagram are as follows: 100, RF transceiver; 110, frequency multiplier signal generation unit; 111, filter, amplification, and frequency multiplier group; 120, first single-frequency carrier signal generation unit; 121, first phase-locked loop; 122, first low-pass filter; 123, first frequency multiplier; 124, first intermediate power amplifier; 125, first bandpass filter; 126, second intermediate power amplifier; 127, second low-pass filter; 130, second single-frequency carrier signal generation unit; 131, second phase-locked loop; 132, third low-pass filter; 133, fixed attenuator; 134, second frequency multiplier; 135, third intermediate power amplifier; 136, second bandpass filter; 140, first mixer unit; 141, first mixer; 142, third bandpass filter; 143, fourth intermediate power amplifier; 144, digitally controlled attenuator; 145, RF power amplifier; 150 151. Second mixer unit; 152. Fourth bandpass filter; 153. Fifth intermediate power amplifier; 160. Third mixer unit; 161. Third mixer; 162. Low noise amplifier; 163. Fifth bandpass filter; 164. Sixth intermediate power amplifier; 165. Second digitally controlled attenuator; 166. Seventh intermediate power amplifier; 170. IQ demodulation unit; 171. Fourth mixer; 172. Sixth bandpass filter; 173. First operational amplifier; 174. Seventh bandpass filter; 175. Fifth mixer; 176. Eighth bandpass filter; 177. Second operational amplifier; 178. Ninth bandpass filter; 200. Digital board; 210. Single-bit ADC; 300. Receiving antenna; 400. Transmitting antenna; 500. Power supply board; 600. Inertial navigation system; 700. Host computer; 800. LoRa antenna. Detailed Implementation

[0069] This invention provides a single-bit synthetic aperture radar device, system, and imaging method thereof. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0070] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0071] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when an element is referred to as "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements present. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0072] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0073] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0074] Please also refer to Figure 1 and Figure 2 The present invention provides a preferred embodiment of a single-bit synthetic aperture radar device, system and imaging method thereof.

[0075] In some embodiments, such as Figure 1As shown, the present invention provides a single-bit synthetic aperture radar device, which includes: a radio frequency transceiver 100, a digital board 200, a receiving antenna 300 and a transmitting antenna 400. The digital board 200 is connected to the radio frequency transceiver 100, and is used to generate radio frequency signals and output them to the radio frequency transceiver 100. The radio frequency transceiver 100 is used to mix a frequency multiplier signal obtained from the radio frequency signal with a first single-frequency carrier signal to obtain a first mixed signal, and to process the first mixed signal to obtain a transmitted signal. It is also used to mix the frequency multiplier signal with a second single-frequency carrier signal to obtain a second mixed signal, and to mix the second mixed signal with an echo signal to obtain a third mixed signal. It is also used to demodulate the third mixed signal to obtain a first intermediate frequency signal and a second intermediate frequency signal. The frequency of the third mixed signal is greater than the frequency of the transmitted signal. The digital board 200 is also used to perform single-bit sampling on the first intermediate frequency signal and the second intermediate frequency signal. The transmitting antenna 400 is connected to the radio frequency transceiver 100, and is used to transmit the transmitted signal. The receiving antenna 300 is connected to the radio frequency transceiver 100, and is used to receive the echo signal.

[0076] Specifically, the RF transceiver 100 is responsible for generating the transmit signal and outputting the intermediate frequency (IF) signal. It has eight interfaces for external connection: a first power interface (power1), a first clock output interface, a first IF signal output interface (RX_Q), a second IF signal output interface (RX_I), an RF receiving interface (RF_IN), a second clock output interface, a signal receiving interface (RX), and a signal transmitting interface (TX). The first power interface (power1) is a J30J connector, the signal receiving interface (RX) and the signal transmitting interface (TX) are 2.92mm connectors, and the remaining interfaces are SMA connectors. The digital board 200 is responsible for radar data transmission, wireless control, dynamic configuration of radar parameters, radar transceiver link control, high-speed radar data storage, peripheral chip control, and control of the inertial navigation system 600 and radio frequency transceiver 100. It has 10 interfaces for external connection: a second power interface (power2), an antenna interface (XS1), a first intermediate frequency signal receiving interface (XS2), a second intermediate frequency signal receiving interface (XS3), a radio frequency signal transmitting interface (XS4), a first clock signal receiving interface (XS6), a second clock signal receiving interface (XS7), a network interface (XS9), a program burning interface (XS11), and an inertial navigation system 600 interface (XS13). Among these, power is a JL27 interface, XS9 is an RJ45 interface, XS13 is a J30J interface, and the others are all SMA interfaces.

[0077] The first power interface, power1, is the 12V power supply interface for the RF transceiver 100. The first clock output interface can output a clock signal of a certain frequency to the digital board 200, serving as a single-bit sampling clock for the digital board 200, for example, 100MHz. The first clock output interface is connected to the first clock signal receiving interface XS6 of the digital board 200. The first intermediate frequency (IF) signal output interface RX_Q and the second IF signal output interface RX_I are respectively connected to the first IF signal receiving interface XS2 and the second IF signal receiving interface XS3 of the digital board 200. The RF receiving interface RF_IN of the RF transceiver 100 is connected to the RF signal transmitting interface XS4 of the digital board 200. The digital board 200 outputs the original linear frequency modulated continuous wave (LFM). Wave (LFMCW) is used as the radio frequency signal; the second clock output interface of the radio frequency transceiver 100 is connected to the second clock signal receiving interface XS7 of the digital board 200, which can use the clock signal generated inside the radio frequency transceiver 100 (e.g., a 6GHz clock signal) after frequency division by the digital board 200 as the operating clock of the system; the second power interface power2 is the 12V power supply interface of the digital board 200; the inertial navigation 600 interface XS13 is used to connect to the MAIN interface of the inertial navigation 600 to power the inertial navigation 600 and realize data communication; the program burning interface XS11 is used for program burning of the digital board 200; the network interface XS9 can be connected to the network port of the host computer 700 through a network cable, or it can be connected wirelessly via WIFI; the antenna interface XS1 can be connected to the LoRa antenna 800 to realize LoRa communication with the host computer 700.

[0078] In this embodiment, the radio frequency (RF) signal generated by the digital board 200 is output to the RF transceiver 100, which performs frequency multiplication on the RF signal to obtain a multiplied signal. A first single-frequency signal generated by the crystal oscillator inside the RF transceiver 100 is modulated to generate a first single-frequency carrier signal, and a second single-frequency signal generated by the crystal oscillator inside the RF transceiver 100 is modulated to generate a second single-frequency carrier signal. The RF transceiver 100 mixes the obtained multiplied signal with the first single-frequency carrier signal to obtain a first mixed signal, and processes the first mixed signal to obtain a transmitted signal, which is then transmitted through the transmitting antenna 400.

[0079] When the transmitted signal interacts with an external object, it is reflected to form a scattered echo. The radio frequency transceiver 100 receives and records these echo signals carrying target information. The receiving antenna 300 of the radio frequency transceiver 100 receives the echo signal. The echo signal is the reflection of the transmitted signal by the external object. Therefore, the frequency of the echo signal is basically the same as that of the transmitted signal.

[0080] The radio frequency transceiver 100 can mix the frequency-doubled signal with the second single-frequency carrier signal to obtain a second mixed signal, and then mix the second mixed signal with the echo signal to obtain a third mixed signal. The third mixed signal is then demodulated to obtain a first intermediate frequency (IF) signal and a second IF signal. The frequency of the frequency-doubled signal is greater than the frequency of the first single-frequency carrier signal, and the frequency of the second mixed signal is greater than the frequency of the transmitted signal. Thus, the frequency of the third mixed signal is higher than the frequency of the echo signal, making its lowest frequency greater than 0Hz. This means that the lowest frequencies of the first and second IF signals obtained from demodulating the third mixed signal are also greater than 0Hz, indicating a frequency shift in the IF signal. This frequency shift can suppress odd harmonics introduced into the IF signal during single-bit sampling, allowing the digital board 200 to perform single-bit sampling of the first and second IF signals. This significantly reduces the amount of sampled data, lowers the data rate, and facilitates signal processing, enabling real-time imaging of the radar imaging system.

[0081] In some embodiments, such as Figure 1 As shown, the single-bit synthetic aperture radar device also includes a power supply board 500; the power supply board 500 is connected to the radio frequency transceiver 100 and the digital board 200 respectively, and the power supply board 500 is used to supply power to the radio frequency transceiver 100 and the digital board 200.

[0082] Specifically, the power supply board 500 is the output power of the UAV. The power supply board 500 is connected to the first power interface of the RF transceiver 100 and the second power interface of the digital board 200, and can output two 12V power supplies to power the RF transceiver 100 and the digital board 200 respectively.

[0083] In some embodiments, such as Figure 1 As shown, the radio frequency transceiver 100 includes a single-bit ADC 210; the single-bit ADC 210 is connected to the radio frequency transceiver 100, and the single-bit ADC 210 is used to perform single-bit sampling on the first intermediate frequency signal and the second intermediate frequency signal.

[0084] In this embodiment, the digital board 200 includes a single-bit ADC 210 (analog-to-digital converter). The single-bit ADC 210 simultaneously samples the first intermediate frequency signal I and the second intermediate frequency signal Q using a single-bit method, significantly reducing the data volume. The sampling data rate is also twice that of the single-frequency signal. The digital board 200 outputs less data but has a high sampling data rate. During operation, the digital board 200 can transmit the sampled data back to the host computer 700 in real time. The host computer 700 then performs real-time imaging based on the sampled data, without waiting for the operation to finish. Furthermore, since there is a frequency offset between the I and Q intermediate frequency signals, it effectively suppresses odd harmonics introduced outside the intermediate frequency signal during single-bit sampling, which is beneficial for signal processing.

[0085] The I and Q intermediate frequency (IF) signals exhibit frequency offset. The working principle of effectively suppressing odd harmonics introduced into the IF signal during single-bit sampling is as follows: Single-bit sampling introduces odd harmonics beyond the original IF signal frequency value. The higher the harmonic order, the lower the amplitude. Typically, the 3rd and 5th harmonics are not negligible in applications, requiring methods to suppress or remove these harmonic components. Without frequency offset, the fundamental frequency (0Hz-f) of the IF signal... max Hz) and 5th harmonic (5 times the fundamental frequency, 0Hz-5f) max There is frequency overlap (Hz), and the 3rd harmonic (3 times the fundamental frequency, 0Hz-3f) exists. max The Hz frequency is very close to the fundamental frequency. After a frequency offset is added to the intermediate frequency signal, the fundamental frequency is located at f. shift -f shift +f max The 5th harmonic frequency is located at 5f. shift -5(f) shift +f max The third harmonic frequency is located at -3f. shift -3(f shift +f max ).

[0086] When the frequency offset satisfies the following relationship, the 3rd and 5th harmonics introduced during single-bit data sampling can be effectively suppressed and will not overlap with the fundamental frequency. The specific relationship is as follows:

[0087]

[0088] Among them, f s It is the sampling rate of a single-bit ADC, f shift It is the frequency offset value, f max It is the maximum frequency of the intermediate frequency signal.

[0089] In some embodiments, such as Figure 1As shown, the single-bit synthetic aperture radar device further includes an inertial navigation system (INS) 600 (i.e., an inertial navigation module), the MAIN interface of which is connected to the INS 600 interface XS13 of the digital board 200. The INS 600 can record the UAV's motion trajectory and attitude, and transmit navigation data to the digital board 200. This navigation data can assist the UAV in imaging, thereby improving imaging accuracy.

[0090] In some embodiments, such as Figure 1 As shown, the single-bit synthetic aperture radar device further includes a LoRa antenna 800, and the antenna interface XS1 of the digital board 200 can be connected to the LoRa antenna 800. The host computer 700 achieves LoRa communication with the digital board 200 through a USB-to-Lora converter. The host computer 700 remotely controls the digital board 200 and monitors the sampling data of the echo signal by the digital board 200 through LoRa communication.

[0091] In some embodiments, such as Figure 1 and Figure 2As shown, the radio frequency transceiver 100 includes: a frequency multiplication signal generation unit 110, a first single-frequency carrier signal generation unit 120, a second single-frequency carrier signal generation unit 130, a first mixing unit 140, a second mixing unit 150, a third mixing unit 160, and an IQ demodulation unit 170. The frequency multiplication signal generation unit 110 is connected to the digital board 200 and is used to process the radio frequency signal to obtain a frequency multiplication signal. The first single-frequency carrier signal generation unit 120 is connected to both the first mixing unit 140 and the digital board 200, and is used to process the single-frequency signal to obtain a first single-frequency carrier signal and a clock signal. The second single-frequency carrier signal generation unit 130 is connected to the second mixing unit 150 and is used to process the single-frequency signal to obtain a second single-frequency carrier signal. The first mixing unit 140 is connected to both the frequency multiplication signal generation unit 110 and the first single-frequency carrier signal generation unit 120. The first mixing unit 150 is used to mix the frequency-doubled signal with the first single-frequency carrier signal to obtain the transmitted signal; the second mixing unit 150 is connected to the frequency-doubled signal generation unit 110 and the second single-frequency carrier signal generation unit 130 respectively, and the second mixing unit 150 is used to mix the frequency-doubled signal with the second single-frequency carrier signal to obtain the second mixed signal; the third mixing unit 160 is connected to the second mixing unit 150, and the third mixing unit 160 is used to mix the echo signal with the second mixed signal to obtain the third mixed signal; the IQ demodulation unit 170 is connected to the third mixing unit 160 and the digital board 200 respectively, and the IQ demodulation unit 170 is used to demodulate the third mixed signal to obtain the first intermediate frequency signal and the second intermediate frequency signal.

[0092] In this embodiment, the frequency multiplier signal generation unit 110 processes the radio frequency signal generated by the digital board 200 and outputs the multiplier signal to the first mixer unit 140 and the second mixer unit 150. The first single-frequency carrier signal generation unit 120 receives the single-frequency signal generated by the crystal oscillator and processes the single-frequency signal to output a first single-frequency carrier signal and a clock signal. In this embodiment, the clock signal may be, but is not limited to, a 6GHz clock signal, which is input to and output to the digital board 200 and used as the system's operating clock after frequency division processing by the digital board 200. The second single-frequency carrier signal generation unit 130 receives the single-frequency signal generated by the crystal oscillator and processes the single-frequency signal to output a second single-frequency carrier signal to the second mixer unit 150.

[0093] The first mixing unit 140 mixes the frequency-multiplied signal with the first single-frequency carrier signal to output a first mixed signal, i.e., the transmitted signal, which is transmitted through the transmitting antenna 400. The second mixing unit 150 mixes the frequency-multiplied signal with the second single-frequency carrier signal to output a second mixed signal to the third mixing unit 160. The receiving antenna 300 receives the echo signal, and the third mixing unit 160 mixes the echo signal with the second mixed signal to obtain a third mixed signal. Subsequently, the third mixed signal is demodulated by the IQ demodulation unit 170 and outputs two intermediate frequency signals to the digital board 200, i.e., the first intermediate frequency signal (I) and the second intermediate frequency signal (Q). The first intermediate frequency signal and the second intermediate frequency signal are sampled by a single-bit DAC in the digital board 200.

[0094] In some embodiments, such as Figure 1 and Figure 2 As shown, the first single-frequency carrier signal generation unit 120 includes: a first phase-locked loop 121, a first low-pass filter 122, a first frequency multiplier 123, a first intermediate power amplifier 124, a first band-pass filter 125, a second intermediate power amplifier 126, and a second low-pass filter 127. The input terminal of the first phase-locked loop 121 receives a single-frequency signal, and the output terminal of the first phase-locked loop 121 is connected to the input terminals of the first low-pass filter 122 and the second intermediate power amplifier 126, respectively. The output terminal of the first low-pass filter 122 is connected to the input terminal of the first frequency multiplier 123; the output terminal of the first frequency multiplier 123 is connected to the input terminal of the first intermediate power amplifier 124; the output terminal of the first intermediate power amplifier 124 is connected to the input terminal of the first band-pass filter 125, and the output terminal of the first band-pass filter 125 is connected to the first mixer unit 140; the output terminal of the second intermediate power amplifier 126 is connected to the input terminal of the first low-pass filter 122, and the output terminal of the low-pass filter is connected to the digital board 200.

[0095] Specifically, the first phase-locked loop 121 receives a single-frequency signal, and the phase-locked loop processes the single-frequency signal to output two signals. One signal passes sequentially through the first low-pass filter 122, the first frequency multiplier 123, the first intermediate power amplifier 124, and the first band-pass filter 125 to obtain a first single-frequency carrier signal. The other signal passes sequentially through the second intermediate power amplifier 126 and the second low-pass filter 127 to obtain a clock signal.

[0096] Further, the second single-frequency carrier signal generation unit 130 includes: a second phase-locked loop 131, a third low-pass filter 132, a fixed attenuator 133, a second frequency multiplier 134, a third intermediate power amplifier 135, and a second band-pass filter 136. The input terminal of the second phase-locked loop 131 receives a single-frequency signal, and the output terminal of the second phase-locked loop 131 is connected to the input terminal of the third low-pass filter 132; the output terminal of the third low-pass filter 132 is connected to the input terminal of the fixed attenuator 133, and the output terminal of the fixed attenuator 133 is connected to the input terminal of the second frequency multiplier 134; the output terminal of the second frequency multiplier 134 is connected to the input terminal of the third intermediate power amplifier; the output terminal of the third intermediate power amplifier 135 is connected to the input terminal of the second band-pass filter 136, and the output terminal of the second band-pass filter 136 is connected to the second mixer unit 150.

[0097] Specifically, the second phase-locked loop 131 receives a single-frequency signal and sequentially passes it through the third low-pass filter 132, the fixed attenuator 133, the second frequency multiplier 134, the third intermediate power amplifier 135, and the second band-pass filter 136 to output a second single-frequency carrier signal. The frequency of the signal output by the second phase-locked loop 131 is greater than the frequency of the signal output by the first phase-locked loop 121; therefore, the frequency of the second single-frequency carrier signal is greater than the frequency of the first single-frequency carrier signal.

[0098] In some embodiments, such as Figure 1 and Figure 2 As shown, the frequency multiplier signal generation unit 110 is a filter-amplified frequency multiplier group 111. The radio frequency signal is generated by the filter-amplified frequency multiplier group 111. In one implementation, the filter-amplified frequency multiplier group 111 consists of a bandpass filter, an amplifier, a bandpass filter, an amplifier, a low-pass filter, a frequency multiplier, a bandpass filter, an amplifier, a frequency multiplier, a bandpass filter, an amplifier, and a low-pass filter. The radio frequency signal generated by the digital board 200 is processed sequentially by a bandpass filter, an amplifier, a bandpass filter, an amplifier, a low-pass filter, a frequency multiplier, a bandpass filter, an amplifier, a frequency multiplier, a bandpass filter, an amplifier, and a low-pass filter to output the frequency multiplier signal.

[0099] In some embodiments, such as Figure 1 and Figure 2As shown, the first mixing unit 140 includes: a first mixer 141, a third bandpass filter 142, a fourth intermediate power amplifier 143, a digitally controlled attenuator 144, and a radio frequency power amplifier 145. The input terminal of the first mixer 141 is connected to the output terminal of the frequency multiplier signal generation unit 110 and the output terminal of the first single-frequency carrier signal generation unit 120, respectively. The output terminal of the first mixer 141 is connected to the input terminal of the third bandpass filter 142. The output terminal of the third bandpass filter 142 is connected to the input terminal of the fourth intermediate power amplifier 143. The output terminal of the intermediate power amplifier is connected to the input terminal of the digitally controlled attenuator 144. The output terminal of the digitally controlled attenuator 144 is connected to the input terminal of the radio frequency power amplifier 145. The output terminal of the radio frequency power amplifier 145 is connected to the transmitting antenna 400.

[0100] Specifically, the first mixer 141 mixes the frequency multiplier signal with the first single-frequency carrier signal and outputs it to the third bandpass filter 142. The signal then passes through the third bandpass filter 142, the fourth intermediate power amplifier, the digitally controlled attenuator 144, and the radio frequency power amplifier 145 in sequence before being output as a transmission signal. The transmission signal is then transmitted to the outside world through the transmission antenna 400.

[0101] Further, the second mixing unit 150 includes: a second mixer 151, a fourth bandpass filter 152, and a fifth intermediate power amplifier 153. The input terminal of the second mixer 151 is connected to the output terminal of the frequency multiplier signal generation unit 110 and the output terminal of the second single-frequency carrier signal generation unit 130, respectively; the output terminal of the second mixer 151 is connected to the input terminal of the fourth bandpass filter 152; the output terminal of the fourth bandpass filter 152 is connected to the input terminal of the fifth intermediate power amplifier 153; and the output terminal of the fifth intermediate power amplifier 153 is connected to the input terminal of the third mixing unit 160.

[0102] Specifically, the second mixer 151 mixes the frequency multiplier signal with the second single-frequency carrier signal and outputs it to the fourth bandpass filter 152. After passing through the fourth bandpass filter 152 and the fifth intermediate power amplifier 153 in sequence, the second mixed signal is output to the third mixer unit 160.

[0103] Further, the third mixing unit 160 includes: a third mixer 161, a low-noise amplifier 162, a fifth bandpass filter 163, a sixth intermediate power amplifier 164, a second digitally controlled attenuator 165, and a seventh intermediate power amplifier 166. The input terminal of the third mixer 161 is connected to the output terminal of the second mixing unit 150 and the output terminal of the low-noise amplifier 162, respectively; the output terminal of the third mixer 161 is connected to the input terminal of the fifth bandpass filter 163; the input terminal of the low-noise amplifier 162 is connected to the receiving antenna 300; the output terminal of the fifth bandpass filter 163 is connected to the input terminal of the sixth intermediate power amplifier 164; the output terminal of the sixth intermediate power amplifier 164 is connected to the input terminal of the second digitally controlled attenuator 165; the output terminal of the second digitally controlled attenuator 165 is connected to the input terminal of the seventh intermediate power amplifier 166; and the output terminal of the seventh intermediate power amplifier 166 is connected to the IQ demodulation unit 170.

[0104] Specifically, the low-noise amplifier 162 is connected to the receiving antenna 300 and can perform noise processing on the echo signal received by the receiving antenna 300. The third mixer 161 mixes the echo signal with the second mixer signal to obtain a third mixer signal, which is then output to the fifth bandpass filter 163. After passing through the fifth bandpass filter 163, the sixth intermediate power amplifier 164, the second digitally controlled attenuator 165, and the seventh intermediate power amplifier 166, the signal is output to the IQ demodulation unit 170.

[0105] In some embodiments, such as Figure 1 and Figure 2As shown, the IQ demodulation unit 170 includes: a fourth mixer 171, a sixth bandpass filter 172, a first operational amplifier 173, a seventh bandpass filter 174, a fifth mixer 175, an eighth bandpass filter 176, a second operational amplifier 177, and a ninth bandpass filter 178. The fifth mixer 175 has its input terminal connected to the output terminal of the third mixer unit 160, and its output terminal connected to the output terminal of the sixth bandpass filter 172. The output terminal of the sixth bandpass filter 172 is connected to the input terminal of the first operational amplifier 173. The output terminal of the first operational amplifier 173 is connected to the input terminal of the seventh bandpass filter 174, and its output terminal is connected to the digital board 200. The fifth mixer 175 has its input terminal connected to the output terminal of the third mixer unit 160, and its output terminal connected to the input terminal of the eighth bandpass filter 176. The output terminal of the eighth bandpass filter 176 is connected to the input terminal of the second operational amplifier 177, and its output terminal is connected to the input terminal of the ninth bandpass filter 178. The output terminal of the ninth bandpass filter 178 is connected to the digital board 200.

[0106] In this embodiment, the third mixing signal is demodulated in two paths. One path passes through the fourth mixer 171, the sixth bandpass filter 172, the first operational amplifier 173, and the seventh bandpass filter 174 in sequence, and outputs a first intermediate frequency signal to the digital board 200. The other path passes through the fifth mixer 175, the eighth bandpass filter 176, the second operational amplifier 177, and the ninth bandpass filter 178 in sequence, and outputs a second intermediate frequency signal to the digital board 200.

[0107] like Figure 2As shown, taking a radio frequency signal of 2.25-2.75 GHz and a single-frequency signal of 100 MHz as an example, the frequency multiplication signal generation unit 110 processes the radio frequency signal and outputs a frequency multiplication signal of 9-11 GHz. The first phase-locked loop 121 processes the 100 MHz single-frequency signal and outputs a 6 GHz signal, which is then filtered and amplified to output a first single-frequency carrier signal of 24 GHz. The second phase-locked loop 131 processes the 100 MHz single-frequency signal and outputs a 6.02625 GHz signal, which is then amplified and filtered to output a second single-frequency carrier signal of 24.105 GHz. The first mixing unit 140 mixes the frequency multiplication signal and the first single-frequency carrier signal to obtain a transmit signal of 33-35 GHz. The second mixing unit 150 mixes the frequency multiplication signal and the second single-frequency carrier signal to obtain a second mixed signal of 33.105-35.105 GHz. After mixing the second mixing signal with the echo signal and demodulating it using IQ, a first intermediate frequency (IF) signal and a second IF signal of 15-35MHz can be obtained. Thus, the received echo signal is not mixed with the transmitted signal, but with a second mixing signal at a frequency higher than the transmitted signal. This ensures that the lowest frequency of the first and second IF signals is not 0Hz, but 15MHz in this embodiment, with a data rate of 200Mbps. This facilitates signal processing after single-bit sampling of the two IF signals, allowing radar data to be transmitted back to the host computer 700 in real time without waiting for the operation to finish. It should be noted that the frequency offset of the RF transceiver 100 mainly depends on the maximum frequency of the output IF signal; a change in the maximum frequency of the IF signal will also change the frequency offset.

[0108] In some embodiments, such as Figure 1 As shown, the present invention also provides a single-bit synthetic aperture radar system, which includes a host computer 700 and a single-bit synthetic aperture radar device as described above. The digital board 200 is connected to the host computer 700, and the host computer 700 is used to obtain image data based on the first intermediate frequency signal and the second intermediate frequency signal. The host computer 700 has an Ethernet port and a USB interface, enabling wired and wireless connections with the digital board 200. After successful connection with the digital board 200, it can remotely control the single-bit synthetic aperture radar device, monitor its status, and read the radar data from the digital board 200, thereby achieving imaging. Because the digital board 200 uses single-bit sampling for the first and second intermediate frequency signals, real-time imaging can be achieved on the host computer 700.

[0109] In some embodiments, such as Figure 3As shown, the present invention also provides an imaging method based on the above-described single-bit synthetic aperture radar system, which includes the following steps:

[0110] S100 controls the digital board to generate radio frequency signals and single-frequency signals; specifically as described in an embodiment of a single-bit synthetic aperture radar device, which will not be repeated here.

[0111] S200. Obtain the frequency multiplication signal based on the radio frequency signal, and obtain the first single-frequency carrier signal and the second single-frequency carrier signal based on the single-frequency signal; as described in an embodiment of a single-bit synthetic aperture radar device, which will not be repeated here.

[0112] S300, the frequency multiplier signal is mixed with the first single-frequency carrier signal to obtain a first mixed signal, and the first mixed signal is processed to obtain a transmitted signal; as described in an embodiment of a single-bit synthetic aperture radar device, which will not be repeated here.

[0113] S400, the frequency-doubled signal is mixed with the second single-frequency carrier signal to obtain a second mixed signal, and the second mixed signal is mixed with the echo signal to obtain a third mixed signal; as described in an embodiment of a single-bit synthetic aperture radar device, it will not be repeated here.

[0114] S500, Demodulate the third mixing signal to obtain a first intermediate frequency signal and a second intermediate frequency signal; wherein, the frequency of the third mixing signal is greater than the frequency of the transmitted signal; as described in an embodiment of a single-bit synthetic aperture radar device, it will not be repeated here.

[0115] S600: Sample the first intermediate frequency signal and the second intermediate frequency signal to obtain radar data, and obtain image data based on the radar data. This is specifically described in an embodiment of a single-bit synthetic aperture radar device, and will not be repeated here.

[0116] In summary, the single-bit synthetic aperture radar device, system, and imaging method provided by this invention have the following beneficial effects:

[0117] The radio frequency transceiver can mix a frequency-doubled signal with a second single-frequency carrier signal to obtain a second mixed signal, and then mix the second mixed signal with the echo signal to obtain a third mixed signal. The third mixed signal is then demodulated to obtain a first intermediate frequency (IF) signal and a second IF signal. The frequency of the frequency-doubled signal is greater than the frequency of the first single-frequency carrier signal, and the frequency of the second mixed signal is greater than the frequency of the transmitted signal. Thus, the frequency of the third mixed signal is higher than the frequency of the echo signal, making its lowest frequency greater than 0Hz. This means that the lowest frequencies of the first and second IF signals obtained from the demodulated third mixed signal are also greater than 0Hz, indicating a frequency shift in the IF signal. This frequency shift can suppress odd harmonics introduced into the IF signal during single-bit sampling, allowing the digital board to sample the first and second IF signals single-bit. This significantly reduces the amount of sampled data, lowers the data rate, and facilitates signal processing, ultimately enabling real-time imaging of the radar imaging system.

[0118] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A single-bit synthetic aperture radar device, characterized in that, include: Radio frequency transceiver, digital board, receiving antenna and transmitting antenna; among which... The digital board is connected to the radio frequency transceiver, and the digital board is used to generate radio frequency signals and output them to the radio frequency transceiver. The radio frequency transceiver is configured to mix a frequency-doubled signal obtained from a radio frequency signal with a first single-frequency carrier signal to obtain a first mixed signal, and process the first mixed signal to obtain a transmitted signal. It is also configured to mix the frequency-doubled signal with a second single-frequency carrier signal to obtain a second mixed signal, and to mix the second mixed signal with an echo signal to obtain a third mixed signal. Furthermore, it is configured to demodulate the third mixed signal to obtain a first intermediate frequency signal and a second intermediate frequency signal; wherein the frequency of the third mixed signal is greater than the frequency of the transmitted signal. The digital board is also used to perform single-bit sampling on the first intermediate frequency signal and the second intermediate frequency signal; The transmitting antenna is connected to the radio frequency transceiver, and the transmitting antenna is used to transmit the transmitting signal. The receiving antenna is connected to the radio frequency transceiver and is used to receive echo signals. The radio frequency transceiver includes: a frequency multiplication signal generation unit, a first single-frequency carrier signal generation unit, a second single-frequency carrier signal generation unit, a first mixing unit, a second mixing unit, a third mixing unit, and an IQ demodulation unit; wherein... The frequency multiplication signal generation unit is connected to the digital board, and the frequency multiplication signal generation unit is used to process the radio frequency signal to obtain the frequency multiplication signal; The first single-frequency carrier signal generation unit is connected to the first mixing unit and the digital board respectively. The first single-frequency carrier signal generation unit is used to process the single-frequency signal to obtain the first single-frequency carrier signal and the clock signal. The second single-frequency carrier signal generation unit is connected to the second mixing unit, and the second single-frequency carrier signal generation unit is used to process the single-frequency signal to obtain the second single-frequency carrier signal; The first mixing unit is connected to the frequency multiplication signal generation unit and the first single-frequency carrier signal generation unit respectively. The first mixing unit is used to mix the frequency multiplication signal and the first single-frequency carrier signal to obtain the transmitted signal. The second mixing unit is connected to the frequency multiplication signal generation unit and the second single-frequency carrier signal generation unit respectively. The second mixing unit is used to perform frequency multiplication processing on the frequency multiplication signal and the second single-frequency carrier signal to obtain a second mixed signal. The third mixing unit is connected to the second mixing unit, and the third mixing unit is used to perform mixing processing on the echo signal and the second mixing signal to obtain a third mixing signal; The IQ demodulation unit is connected to the third mixing unit and the digital board respectively. The IQ demodulation unit is used to demodulate the third mixing signal to obtain the first intermediate frequency signal and the second intermediate frequency signal. The first single-frequency carrier signal generation unit includes: a first phase-locked loop, a first low-pass filter, a first frequency multiplier, a first intermediate power amplifier, a first band-pass filter, a second intermediate power amplifier, and a second low-pass filter; wherein, The input terminal of the first phase-locked loop is connected to a single-frequency signal, and the output terminal of the first phase-locked loop is connected to the input terminal of the first low-pass filter and the input terminal of the second intermediate power amplifier, respectively. The output of the first low-pass filter is connected to the input of the first frequency multiplier. The output terminal of the first frequency multiplier is connected to the input terminal of the first intermediate power amplifier; The output terminal of the first intermediate power amplifier is connected to the input terminal of the first bandpass filter, and the output terminal of the first bandpass filter is connected to the first mixer unit; The output terminal of the second intermediate power amplifier is connected to the input terminal of the first low-pass filter, and the output terminal of the low-pass filter is connected to the digital board; The second single-frequency carrier signal generation unit includes: a second phase-locked loop, a third low-pass filter, a fixed attenuator, a second frequency multiplier, a third intermediate power amplifier, and a second band-pass filter; wherein, The input terminal of the second phase-locked loop is connected to a single-frequency signal, and the output terminal of the second phase-locked loop is connected to the input terminal of the third low-pass filter; The output of the third low-pass filter is connected to the input of the fixed attenuator, and the output of the fixed attenuator is connected to the input of the second frequency multiplier. The output of the second frequency multiplier is connected to the input of the third intermediate power amplifier; The output of the third intermediate power amplifier is connected to the input of the second bandpass filter, and the output of the second bandpass filter is connected to the second mixer unit.

2. The single-bit synthetic aperture radar device according to claim 1, characterized in that, It also includes a power supply board; the power supply board is connected to the radio frequency transceiver and the digital board respectively, and the power supply board is used to supply power to the radio frequency transceiver and the digital board.

3. The single-bit synthetic aperture radar device according to claim 1, characterized in that, The radio frequency transceiver includes a single-bit ADC; the single-bit ADC is connected to the radio frequency transceiver and is used to perform single-bit sampling on the first intermediate frequency signal and the second intermediate frequency signal.

4. The single-bit synthetic aperture radar device according to claim 1, characterized in that, The first mixing unit includes: a first mixer, a third bandpass filter, a fourth intermediate power amplifier, a digitally controlled attenuator, and an RF power amplifier; wherein, The input terminal of the first mixer is connected to the output terminal of the frequency multiplication signal generation unit and the output terminal of the first single-frequency carrier signal generation unit, respectively, and the output terminal of the first mixer is connected to the input terminal of the third bandpass filter; The output of the third bandpass filter is connected to the input of the fourth intermediate power amplifier, and the output of the intermediate power amplifier is connected to the input of the digitally controlled attenuator. The output terminal of the digitally controlled attenuator is connected to the input terminal of the radio frequency power amplifier, and the output terminal of the radio frequency power amplifier is connected to the transmitting antenna. The second mixing unit includes: a second mixer, a fourth bandpass filter, and a fifth intermediate power amplifier; wherein, The input terminal of the second mixer is connected to the output terminal of the frequency multiplication signal generation unit and the output terminal of the second single-frequency carrier signal generation unit, respectively, and the output terminal of the second mixer is connected to the input terminal of the fourth bandpass filter; The output of the fourth bandpass filter is connected to the input of the fifth intermediate power amplifier; The output terminal of the fifth intermediate power amplifier is connected to the input terminal of the third mixer unit; The third mixing unit includes: a third mixer, a low-noise amplifier, a fifth bandpass filter, a sixth intermediate power amplifier, a second digitally controlled attenuator, and a seventh intermediate power amplifier; wherein... The input terminal of the third mixer is connected to the output terminal of the second mixer unit and the output terminal of the low-noise amplifier, respectively, and the output terminal of the third mixer is connected to the input terminal of the fifth bandpass filter. The input terminal of the low-noise amplifier is connected to the receiving antenna; The output of the fifth bandpass filter is connected to the input of the sixth intermediate power amplifier, and the output of the sixth intermediate power amplifier is connected to the input of the second digitally controlled attenuator. The output terminal of the second digitally controlled attenuator is connected to the input terminal of the seventh intermediate power amplifier, and the output terminal of the seventh intermediate power amplifier is connected to the IQ demodulation unit.

5. The single-bit synthetic aperture radar device according to claim 1, characterized in that, The IQ demodulation unit includes: a fourth mixer, a sixth bandpass filter, a first operational amplifier, a seventh bandpass filter, a fifth mixer, an eighth bandpass filter, a second operational amplifier, and a ninth bandpass filter; wherein, The input terminal of the fifth mixer is connected to the output terminal of the third mixer unit, and the output terminal of the fifth mixer is connected to the output terminal of the sixth bandpass filter. The output of the sixth bandpass filter is connected to the input of the first operational amplifier; The output terminal of the first operational amplifier is connected to the input terminal of the seventh bandpass filter, and the output terminal of the seventh bandpass filter is connected to the digital board; The input terminal of the fifth mixer is connected to the output terminal of the third mixer unit, and the output terminal of the fifth mixer is connected to the input terminal of the eighth bandpass filter. The output of the eighth bandpass filter is connected to the input of the second operational amplifier, and the output of the second operational amplifier is connected to the input of the ninth bandpass filter. The output of the ninth bandpass filter is connected to the digital board.

6. The single-bit synthetic aperture radar device according to claim 1, characterized in that, The frequency multiplication signal generation unit is a filter amplification frequency multiplication group, and the radio frequency signal is generated by the filter amplification frequency multiplication group.

7. A single-bit synthetic aperture radar system, characterized in that, The device includes a host computer and a single-bit synthetic aperture radar device as described in any one of claims 1-6, wherein the digital board is connected to the host computer, and the host computer is used to obtain image data based on the first intermediate frequency signal and the second intermediate frequency signal.

8. An imaging method based on the single-bit synthetic aperture radar system of claim 7, characterized in that, include: The control digital board generates radio frequency signals and single-frequency signals; The frequency multiplier signal is obtained from the radio frequency signal, and the first single-frequency carrier signal and the second single-frequency carrier signal are obtained from the single-frequency signal. The first mixed signal is obtained by mixing the frequency multiplier signal with the first single-frequency carrier signal, and the first mixed signal is processed to obtain the transmitted signal. The frequency multiplier signal is mixed with the second single-frequency carrier signal to obtain a second mixed signal, and the second mixed signal is mixed with the echo signal to obtain a third mixed signal. The third mixing signal is demodulated to obtain a first intermediate frequency signal and a second intermediate frequency signal; wherein the frequency of the third mixing signal is greater than the frequency of the transmitted signal; Radar data is obtained by sampling the first intermediate frequency signal and the second intermediate frequency signal, and image data is obtained based on the radar data.

Images