A sparse synthetic bandwidth radar system

Abstract

The present invention discloses a sparse synthetic bandwidth radar system, which includes a transmitter part and a receiver part. The transmitter part includes a frequency multiplier, an amplifier, a multi-band full-duplexer, and a multi-band antenna. When the transmitter works, the same frequency-modulated continuous wave signal is input to the input ends of the frequency multiplier and the amplifier. One path is amplified by the amplifier and then output to the multi-band full-duplexer, and the other path outputs a signal to the multi-band full-duplexer through the frequency multiplier. These two signals with different frequencies pass through the multi-band full-duplexer and are finally transmitted through the multi-band antenna. The receiver part includes a mixer, a multi-band full-duplexer, a multi-band antenna, and a digital baseband. When the receiver works, the multi-band antenna receives the reflected signal and outputs it to the mixer through the multi-band full-duplexer for down-conversion. The output intermediate frequency signal IF then enters the digital baseband circuit to reconstruct the intermediate frequency signal response of the wideband frequency-modulated continuous wave signal, and further obtain information such as the distance, speed, and angle of the target.

Description

Technical Field

[0001] The present invention belongs to the field of communication technologies, and particularly relates to a sparse synthetic bandwidth radar system. Background Art

[0002] As a technology for wireless detection and sensing, the detection range resolution of a radar is related to its modulation bandwidth. The range resolution of a frequency-modulated continuous-wave (FMCW) radar is ΔR = c / 2BW, where c is the speed of light and BW is the modulation bandwidth. The wider the bandwidth, the higher the range resolution that the system can achieve. In a traditional radar transceiver chip system, the modulation bandwidth is limited by the bandwidth of each module in the system, including the frequency source, frequency multiplier, amplifier, and antenna, etc., facing the problem of narrow bandwidth of circuit modules, making it difficult to improve the range resolution. To break through the limitation of the module bandwidth and expand the modulation bandwidth of the radar system, the literature (X. Yi, C. Wang, X. Chen, J. Wang, J. Grajal and R. Han, “A 220-to-320-GHz FMCW radar in 65-nm CMOS using a frequency-comb architecture,” IEEE Journal of Solid-State Circuits, vol. 56, no. 2, Feb. 2021.) proposed an FMCW radar transceiver architecture with a multi-channel comb structure. This radar cascades consecutive CH 1 , CH 2 to CH N multiple channels. Each channel is composed of a transceiver with a narrow bandwidth. A wide equivalent modulation bandwidth BW is synthesized in the digital baseband. This technology can be called synthetic bandwidth radar. Synthetic bandwidth radar synthesizes a wide equivalent modulation bandwidth by cascading transceivers with narrow bandwidths to improve the range resolution. The specific principle is explained as follows: The narrowband transceiver sequentially increases the frequency of the FMCW signal by a bandwidth interval through a single-sideband mixer and then gives it to the transceiver of the next channel. In this way, the narrowband FMCW signal is sequentially shifted upward and finally transmitted simultaneously by multiple channels. Therefore, multiple narrowband FMCW signals are just equivalent to a broadband FMCW signal. Theoretical analysis shows that the intermediate-frequency signal of each channel transceiver is not affected by the initial phase of this channel but only related to the distance of the target. Therefore, the intermediate-frequency signals of multiple channels can be spliced together in the digital baseband to achieve broadband FMCW synthetic bandwidth. However, this technology has the disadvantages of large occupied area and high power consumption of multiple channels. Summary of the Invention

[0003] In view of the disadvantages of the above-mentioned traditional radar with limited bandwidth and the large occupied area and high power consumption of multi-channels in synthetic bandwidth radar, the present invention provides a sparse synthetic bandwidth radar system that can maintain the extended bandwidth of the synthetic bandwidth radar. At the same time, the problems of large occupied area and high power consumption of multi-channels are solved, so as to obtain a sparse synthetic bandwidth radar system with high range resolution and small area and power consumption. The sparse synthetic bandwidth radar means that the bandwidth included in the synthetic bandwidth radar is not continuous and has gaps. Specific algorithms can be used to reconstruct the signals with missing bandwidth, and finally a large bandwidth can be obtained, so as to obtain high range resolution. Assume that the synthetic bandwidth radar has n transceiver (the combination of transmitter and receiver is called transceiver) channels, and the modulation bandwidth is BW.

[0004] The present invention is realized by at least one of the following technical solutions.

[0005] A sparse synthetic bandwidth radar system includes a transmitter part and a receiver part. The transmitter part includes a frequency multiplier, an amplifier, a multi-band full-duplexer, and a multi-band antenna. The receiver part includes a mixer, a digital baseband, a multi-band full-duplexer, and a multi-band antenna. The output ends of the frequency multiplier and the amplifier are both connected to the multi-band full-duplexer. The input end of the mixer is connected to the output end of the multi-band full-duplexer. The output end of the mixer is interconnected with the digital baseband. The multi-band full-duplexer is connected to the multi-band antenna.

[0006] Further, when the transmitter works, a frequency-modulated continuous wave signal FMCW with a frequency of f 0 is input to the input ends of the frequency multiplier and the amplifier. One path is amplified by the amplifier and then output to the multi-band duplexer, and the other path is output to the multi-band full-duplexer by the frequency multiplier with a signal of frequency 2f 0 . The two signals with different frequencies pass through the multi-band full-duplexer and are then transmitted through the multi-band antenna.

[0007] Further, when the receiver works, the multi-band antenna receives the reflected signals with frequencies f 0 and 2f 0 , and outputs them to the mixer through the multi-band full-duplexer for down-conversion. The intermediate frequency signal IF is output to the digital baseband for signal reconstruction and analysis, so as to obtain the information of the target.

[0008] Further, the frequency-modulated continuous wave FMCW transmitted signal is:

[0009]

[0010]

[0011] f c,n =f c1 +BW·(n - 1), n = 1, 2…, N

[0012] where t is time, A TX is the amplitude of the transmitted signal, f c,n is the signal frequency of the n-th transmitter, n is the n-th transmitter, f c1 is the signal frequency of the first transmitter, K is the modulation slope of the frequency-modulated continuous wave (FMCW) transmitted signal, BW is the modulation bandwidth, T m is the modulation period of the bandwidth, is the initial phase, j is the imaginary unit, and N represents an integer.

[0013] Furthermore, after a propagation delay time τ of the signal, the reflected signal received by the receiver is:

[0014]

[0015] where L TX2RX is the signal attenuation caused by the transmitted signal to the received reflected signal, s TX,n (t - τ) frequency-modulated continuous wave (FMCW) transmitted signal, A RX is the amplitude of the received reflected signal, f c,n is the signal frequency of the n-th transmitter, τ is the propagation delay time of the signal from transmission to reception, is the initial phase, t is time, and K is the modulation slope of the frequency-modulated continuous wave (FMCW) transmitted signal.

[0016] Furthermore, when the signal propagation delay time τ is determined, the phase offset between different transceiver channels changes linearly. Based on the intermediate-frequency signal and the linear change relationship of the transceiver channels, the intermediate-frequency signal responses of other transceiver channels are deduced.

[0017] Furthermore, the intermediate-frequency signal IF after down-conversion is:

[0018]

[0019] where A IF is the amplitude of the intermediate-frequency signal, K is the modulation slope of the frequency-modulated continuous wave (FMCW) transmitted signal, BW is the modulation bandwidth, f c,n is the signal frequency of the n-th transmitter, n is the n-th transceiver channel, f c1 is the signal frequency of the first transmitter, τ is the propagation delay time of the signal from transmission to reception, t is time, and K is the modulation slope of the frequency-modulated continuous wave (FMCW) transmitted signal.

[0020] Furthermore, for different transceiver channels, their phase offsets are:

[0021]

[0022] ∠F n (ω) = 2π((f c1 + BW·(n - 1))τ - 0.5Kτ 2 );

[0023] ω = 2π(Kτ)

[0024] Wherein, BW is the modulation bandwidth, τ is the propagation delay time from signal transmission to reception, ∠F n (ω) is the initial phase of the intermediate frequency signal of the nth transceiver channel, q is the qth transceiver channel, p is the pth transceiver channel, ω is the angular frequency, f c1 is the signal frequency of the first transmitter, n is the nth transmitter, and K is the modulation slope of the frequency-modulated continuous wave FMCW transmitted signal.

[0025] Furthermore, the multi-band full-duplexer is a dual-band full-duplexer or a triple-band full-duplexer or a quadruple-band full-duplexer.

[0026] Furthermore, the multi-band antenna is a dual-band antenna or a triple-band antenna or a quadruple-band antenna.

[0027] Compared with the existing technology, the beneficial effects of the present invention are as follows:

[0028] The present invention can save the area and power consumption of 6 transceiver channels. The sparse synthetic bandwidth radar system of the present invention can greatly reduce the occupied area, power consumption and cost of the radar system, and at the same time has the large bandwidth possessed by the synthetic radar, thereby obtaining high range resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] By describing the embodiments of the present invention in detail in conjunction with the accompanying drawings, the above and other objects, features and advantages of the present invention will become clearer, wherein:

[0030] Figure 1 is the dual-band system architecture diagram of the sparse synthetic bandwidth radar system according to the embodiment of the present invention;

[0031] Figure 2 is the schematic diagram of the working frequency f of the dual-band system of the sparse synthetic bandwidth radar according to the embodiment of the present invention changing with time t;

[0032] Figure 3 is the schematic diagram of the principles of the synthetic bandwidth radar and the sparse synthetic bandwidth radar according to the embodiment of the present invention;

[0033] Figure 4 is the signal reconstruction result diagram of the sparse synthetic bandwidth radar according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0035] Example 1

[0036] like Figure 1 A sparse synthetic bandwidth radar system shown includes a transmitter part and a receiver part (the transmitter and the receiver are collectively referred to as a transceiver, and may also be referred to as a transceiver channel), wherein the transmitter part includes a frequency multiplier, an amplifier, a dual-band full-duplexer, and a dual-band antenna, and the receiver part includes a mixer, a digital baseband, a dual-band full-duplexer, and a dual-band antenna; the output ends of the frequency multiplier and the amplifier are both connected to the dual-band full-duplexer, the input end of the mixer is connected to the output end of the dual-band full-duplexer, the output end of the mixer is interconnected with the digital baseband, and the dual-band full-duplexer is connected to the dual-band antenna.

[0037] The sparse synthetic bandwidth radar of the present invention means that the bandwidth contained in the synthetic bandwidth radar is not continuous but has gaps. A specific algorithm can be used to reconstruct the signal with missing bandwidth and finally achieve the same bandwidth as the synthetic bandwidth radar, thereby improving the distance resolution.

[0038] The working principle is explained as follows: When the transmitter is working, the transmitter input is the same frequency modulated continuous wave (FMCW) signal f 0 One of them is amplified by the amplifier and then output, and the other is output at a frequency of 2f after passing through the doubler. 0 The two signals of different frequencies pass through the dual-band full-duplexer and are finally transmitted through the dual-band antenna. The transmitted signal propagates in space and encounters the target to generate a reflected signal, which is received by the receiver. The reflected signal is down-converted by the mixer to generate an intermediate frequency signal IF that is input into the digital baseband to realize a sparse synthetic bandwidth radar with a dual-band architecture. According to the base frequency f 0 and the second harmonic 2f 0 The generated intermediate frequency signal IF can reconstruct the intermediate frequency signal response corresponding to the broadband FMCW signal in the digital baseband, thereby obtaining relevant information of the target.

[0039] The operating frequency is f 0 and 2f 0 The dual-band architecture is a special case of the sparse synthetic bandwidth radar system, that is, 0 and 2f 0 The two frequency bands are reconstructed and synthesized into f 0 To 2f 0 IF signal response and bandwidth across the entire frequency band.

[0040] For a sparse synthetic bandwidth radar, the vacancy rate of the transceiver channels can be flexibly selected compared to a continuous synthetic bandwidth radar.

[0041] The frequency-modulated continuous wave (FMCW) transmitted signal is as follows:

[0042]

[0043]

[0044] f c,n = f c1 + BW·(n - 1), n = 1, 2…, N

[0045] where t is time, A TX is the amplitude of the transmitted signal, f c,n is the signal frequency of the nth transmitter, n is the nth transmitter, f c1 is the signal frequency of the first transmitter, K is the modulation slope of the frequency-modulated continuous wave (FMCW) transmitted signal, BW is the modulation bandwidth, T m is the modulation period of the bandwidth, is the initial phase, j is the imaginary unit, and N represents an integer.

[0046] According to the characteristics of the transmitted signal, after a propagation delay time τ of the signal, the reflected signal received by the receiver is

[0047]

[0048] where L TX2RX is the signal attenuation caused from the transmitted signal to the received reflected signal, s TX,n (t - τ) frequency-modulated continuous wave (FMCW) transmitted signal, A RX is the amplitude of the received reflected signal, f c,n is the signal frequency of the nth transmitter, τ is the propagation delay time from transmission to reception of the signal, is the initial phase, t is time, and K is the modulation slope of the frequency-modulated continuous wave (FMCW) transmitted signal.

[0049] The intermediate frequency (IF) signal after down-conversion is as follows:

[0050]

[0051] where A IF is the amplitude of the intermediate frequency signal, K is the modulation slope of the frequency-modulated continuous wave (FMCW) transmitted signal, BW is the modulation bandwidth, f c,n is the signal frequency of the nth transmitter, n is the nth transceiver channel, f c1f is the signal frequency of the first transmitter, τ is the propagation delay time of the signal from transmission to reception, t is time, and K is the modulation slope of the frequency-modulated continuous-wave (FMCW) transmitted signal.

[0052] For different transceiver channels, the phase offset is:

[0053]

[0054] ∠F n (ω) = 2π((f c1 + BW·(n - 1))τ - 0.5Kτ 2 );

[0055] ω = 2π(Kτ)

[0056] where BW is the modulation bandwidth, τ is the propagation delay time of the signal from transmission to reception, ∠F n (ω) is the initial phase of the intermediate-frequency signal of the q-th transceiver channel, q is the q-th transceiver channel, p is the p-th transceiver channel, ω is the angular frequency, f c1 is the signal frequency of the first transmitter, n is the n-th transmitter, and K is the modulation slope of the frequency-modulated continuous-wave (FMCW) transmitted signal.

[0057] When the signal propagation delay time τ is determined, the phase offset between different transceiver channels changes linearly. Therefore, if the intermediate-frequency signal of one of the transceiver channels is known, the intermediate-frequency signal response of other transceiver channels can be deduced based on the linear variation relationship. For example, given the intermediate-frequency signal s IF,1 (t) of the first transceiver channel and the intermediate-frequency signal s IF,n (t) of the n-th transceiver channel, the intermediate-frequency signal responses from the 2nd to the n - 1-th can be deduced according to the formula for the phase difference Δφ τ . A sparse synthetic bandwidth radar system can obtain the same bandwidth as a continuous multi-transceiver channel synthetic bandwidth radar with a small number of sparse, discontinuous, and missing transceiver channels.

[0058] Figure 2 The figure shows a schematic diagram of the variation of the signal frequency f with time t in the dual-frequency system of the sparse synthetic bandwidth radar according to an embodiment of the present invention. The abscissa is time t, and the ordinate represents the signal frequency f. The signal frequency f changes linearly with time t. The change slope of the fundamental frequency signal f 0 is K, and the change slope of the second-harmonic signal frequency 2f 0 is 2K. The middle dashed line represents the bandwidth of the missing transceiver channels. The total modulation bandwidth is BW.

[0059] As Figure 3The figure shows the schematic working principles of a synthetic bandwidth radar and a sparse synthetic bandwidth radar. Here, the abscissa represents time t, and the ordinate represents the operating frequency f of the radar. CH 1 represents the first transceiver channel, and CH N represents the Nth transceiver channel. As Figure 3 shown in a of, the operating signal of each transceiver channel is a frequency-modulated continuous wave (FMCW) signal, that is, the operating frequency f changes linearly in a sawtooth wave with time t. The thick black line represents the transmitted signal, and the thin black line represents the received signal. Figure 3 The synthetic bandwidth radar in a cascades consecutive CH 1 , CH 2 to CH N multiple transceiver channels. Each channel consists of a transceiver with a relatively narrow bandwidth. A wide equivalent modulation bandwidth BW is synthesized in the digital baseband. The total bandwidth BW of the synthetic bandwidth radar is synthesized from the narrow bandwidths of N transceiver channels and can be called a synthetic bandwidth radar. The synthetic bandwidth radar synthesizes a wide equivalent modulation bandwidth by cascading transceivers with narrow bandwidths to improve the range resolution. The specific principle is as follows: The narrowband transceiver sequentially increases the frequency of the FMCW signal by a bandwidth interval through a single-sideband mixer and then gives it to the transceiver of the next channel. In this way, the narrowband FMCW signal is sequentially shifted upward and finally transmitted simultaneously by multiple channels. Therefore, multiple narrowband FMCW signals are just equivalent to a broadband FMCW signal; theoretical analysis shows that the intermediate-frequency signal of each channel transceiver is not affected by the initial phase of this channel but only related to the distance of the target; therefore, the intermediate-frequency signals of multiple channels can be spliced together in the digital baseband to achieve broadband FMCW synthetic bandwidth.

[0060] Taking a synthetic bandwidth radar with n = 8 transceiver channels (n is the number of transceiver channels) as an example, to construct a sparse synthetic bandwidth radar, 2 transceiver channels can be selected, or 3 transceiver channels can be selected, or 4 transceiver channels can be selected, corresponding to vacancy rates of 75%, 62.5%, and 50% respectively, and so on. All of these belong to sparse synthetic bandwidth radars.

[0061] Figure 3 b of shows the schematic working principle of the sparse synthetic bandwidth radar of this embodiment. The bandwidth it contains is not continuous and is only composed of the bandwidths of transceiver channels CH 1 and CH N . The bandwidths of the transceiver channels between CH 1 and CH N are vacant. Through the signal processing algorithm in the digital baseband, the signals with vacant bandwidths can be reconstructed and then synthesized into an equivalent modulation bandwidth, and finally a large bandwidth BW is obtained, thereby obtaining a high range resolution. Therefore, the sparse synthetic bandwidth radar can achieve the same performance asFigure 3 The a multi-transceiver channel synthetic bandwidth radar has the same bandwidth BW, so the area, power consumption, and cost of its system are greatly reduced.

[0062] Figure 4 Shown is the result after reconstructing the intermediate frequency signal IF of a sparse synthetic bandwidth radar signal with a vacancy rate of 75% (i.e., the synthetic bandwidth radar requires 8 transceiver channels, and the sparse synthetic bandwidth radar requires 2 transceiver channels) verified by simulation in the commercial mathematical software Matlab. It can be seen from the figure that there are two targets in the actual target signal, and the reconstructed target signal can distinguish the number and frequency of the targets. Therefore, the signal after reconstruction by the sparse synthetic bandwidth radar can correctly reflect the information of the real targets.

[0063] Taking the 8-transceiver-channel synthetic bandwidth radar as an example, only 2 transceiver channels (with a vacancy rate of 75%) are needed, which can save the area and power consumption of 6 transceiver channels, and at the same time have the large bandwidth possessed by the synthetic radar, thus obtaining high range resolution.

[0064] Embodiment 2

[0065] A sparse synthetic bandwidth radar system in this embodiment includes a transmitter part and a receiver part. The transmitter part includes a frequency multiplier, an amplifier, a three-band full-duplexer, and a three-band antenna. The receiver part includes a mixer, a digital baseband, a three-band full-duplexer, and a three-band antenna;

[0066] The output ends of the frequency multiplier and the amplifier are both connected to the three-band full-duplexer. The input end of the mixer is connected to the output end of the three-band full-duplexer. The output end of the mixer is interconnected with the digital baseband. The three-band full-duplexer is connected to the three-band antenna.

[0067] According to the principle of the sparse synthetic bandwidth radar, this embodiment uses a sparse method with 3 transceiver channels to construct the sparse synthetic bandwidth radar. For example, for a synthetic bandwidth radar that originally requires 8 transceiver channels, it can choose to use CH 1 , CH 5 , CH 8 These three transceiver channels as the actually working transceiver channels, and the transceiver channels between CH 1 and CH 5 , CH 5 and CH 8 are vacant.

[0068] Embodiment 3

[0069] A sparse synthetic bandwidth radar system according to this embodiment includes a transmitter part and a receiver part. The transmitter part includes a frequency multiplier, an amplifier, a four-band full-duplexer, and a four-band antenna. The receiver part includes a mixer, a digital baseband, a four-band full-duplexer, and a four-band antenna;

[0070] The output ends of the frequency multiplier and the amplifier are both connected to the four-band full-duplexer. The input end of the mixer is connected to the output end of the four-band full-duplexer. The output end of the mixer is interconnected with the digital baseband. The four-band full-duplexer is connected to the four-band antenna.

[0071] According to the principle of the sparse synthetic bandwidth radar, this embodiment constructs a sparse synthetic bandwidth radar in a sparse manner using 4 transceiver channels. For example, for a synthetic bandwidth radar that originally requires 7 transceiver channels, it can be selected to use CH 1 、CH 3 、CH 5 、CH 7 These four transceiver channels as the actual working transceiver channels, and the transceiver channels between CH 1 and CH 3 , CH 3 and CH 5 , CH 5 and CH 7 are vacant.

[0072] For the sparse synthetic bandwidth radars of Example 1, Example 2, and Example 3, the number of transceiver channels can be selected according to actual application requirements. The more the actual number of transceiver channels, the more beneficial it is for reconstructing the intermediate frequency signal response, but it will increase the area and power consumption.

[0073] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art in the relevant technical field can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A sparse synthetic bandwidth radar system, characterized in that, it includes a transmitter part and a receiver part. The transmitter part includes a frequency multiplier, an amplifier, a multi-band full-duplexer, and a multi-band antenna. The receiver part includes a mixer, a digital baseband, a multi-band full-duplexer, and a multi-band antenna. The output ends of the frequency multiplier and the amplifier are both connected to the multi-band full-duplexer. The input end of the mixer is connected to the output end of the multi-band full-duplexer. The output end of the mixer is interconnected with the digital baseband. The multi-band full-duplexer is connected to the multi-band antenna; When the transmitter is working, a frequency-modulated continuous wave signal FMCW with a frequency of f is input to the input ends of the frequency multiplier and the amplifier. 0 One path is amplified by the amplifier and then output to the multi-band duplexer, and the other path is output to the multi-band full-duplexer with a signal of frequency 2f after passing through the frequency multiplier. 0 The two signals with different frequencies pass through the multi-band full-duplexer and are then transmitted through the multi-band antenna. When the receiver is working, the multi-band antenna receives the reflected signals of frequencies f 0 and 2f 0 which are output to the mixer through the multi-band full-duplexer for down-conversion, and the intermediate frequency signal IF is output to the digital baseband for signal reconstruction and analysis, so as to obtain the information of the target; The frequency-modulated continuous wave (FMCW) transmit signal is: f c,n = f c1 + BW·(n - 1), n = 1, 2…, N where t is time, A TX is the amplitude of the transmitted signal, f c,n is the signal frequency of the n-th transmitter, n is the n-th transmitter, f c1 is the signal frequency of the first transmitter, K is the modulation slope of the frequency-modulated continuous wave (FMCW) transmitted signal, BW is the modulation bandwidth, T m is the modulation period of the bandwidth, is the initial phase, j is the imaginary unit, and N represents an integer.

2. The sparse synthetic bandwidth radar system according to claim 1, characterized in that, According to the characteristics of the transmit signal, after a propagation delay time τ of the signal, the reflected signal received by the receiver is: Among them, L TX2RX is the signal attenuation caused when the transmitted signal reaches the received reflected signal, s TX,n (t - τ) frequency-modulated continuous wave FMCW transmitted signal, A RX is the amplitude of the received reflected signal, f c,n is the signal frequency of the nth transmitter, τ is the propagation delay time from transmission to reception of the signal, is the initial phase, t is the time, and K is the modulation slope of the frequency-modulated continuous wave FMCW transmitted signal.

3. The sparse synthetic bandwidth radar system according to claim 2, characterized in that, When the signal propagation delay time τ is determined, the phase offset between different transceiver channels changes linearly. Based on the intermediate frequency signal of one of the transceiver channels and the linear change relationship, the intermediate frequency signal responses of other transceiver channels are deduced.

4. The sparse synthetic bandwidth radar system according to claim 2, characterized in that, The intermediate frequency signal IF after down-conversion is: Among them, A IF is the amplitude of the intermediate frequency signal, K is the modulation slope of the frequency-modulated continuous wave FMCW transmitted signal, BW is the modulation bandwidth, f c,n is the signal frequency of the nth transmitter, n is the nth transceiver channel, f c1 is the signal frequency of the first transmitter, τ is the propagation delay time of the signal from transmission to reception, t is the time, and K is the modulation slope of the frequency-modulated continuous wave FMCW transmitted signal.

5. The sparse synthetic bandwidth radar system according to any one of claims 1 to 4, characterized in that, For different transceiver channels, the phase offset is: ∠F n (ω) = 2π((f c1 + BW·(n - 1))τ - 0.5Kτ 2 ); ω = 2π(Kτ) where BW is the modulation bandwidth, τ is the propagation delay time from signal transmission to reception, ∠F n (ω) is the initial phase of the intermediate frequency signal of the nth transceiver channel, q is the qth transceiver channel, p is the pth transceiver channel, ω is the angular frequency, f c1 is the signal frequency of the first transmitter, n is the nth transmitter, and K is the modulation slope of the frequency-modulated continuous wave FMCW transmission signal.

6. The sparse synthetic bandwidth radar system according to claim 5, characterized in that, The multi-band full-duplexer is a dual-band full-duplexer or a triple-band full-duplexer or a quadruple-band full-duplexer.

7. The sparse synthetic bandwidth radar system according to claim 6, characterized in that, The multi-band antenna is a dual-band antenna or a triple-band antenna or a quadruple-band antenna.

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