Continuous wave radar detection method and apparatus, radar, computer readable storage medium

Abstract

The application relates to the radar technical field and discloses a continuous wave radar detection method, which comprises the following steps: generating an initial radio frequency carrier signal; applying a preset frequency offset to the initial radio frequency carrier signal to generate a transmission signal; radiating the transmission signal to a detection space through a transmission antenna; receiving a return signal formed by reflection of the transmission signal by a target in the detection space through a receiving antenna; and mixing the return signal with the initial radio frequency carrier signal to obtain a first intermediate frequency signal; wherein the preset frequency offset is configured so that, for a stationary target, the first intermediate frequency signal is a signal with a frequency equal to a preset non-zero frequency value; and the first intermediate frequency signal is processed to obtain information related to the state of the target. The spectrum of the effective signal is actively shifted to a frequency point away from a high-noise low-frequency area, and the detection sensitivity for stationary or micro-motion targets is enhanced. The application further discloses a continuous wave radar detection device, a radar and a storage medium.

Description

Technical Field

[0001] This application relates to the field of radar technology, such as a continuous wave radar detection method and apparatus, radar, and computer-readable storage medium. Background Technology

[0002] Currently, continuous wave radar, especially Doppler radar, is widely used in many fields due to its simple structure, high cost-effectiveness, and ability to accurately measure the radial velocity of targets. However, in practical applications, especially when facing stationary or extremely low-speed targets, the system's detection sensitivity faces a severe challenge. The Doppler frequency of the generated echo is extremely low, causing effective signal information to be easily submerged in noise.

[0003] To address the aforementioned sensitivity challenges, related technologies typically focus on suppressing low-frequency noise during signal processing to extract weak, useful signals from the noisy background. For example, AC-coupled circuits can be used to block DC components, thereby eliminating interference introduced by inherent DC offset in the hardware circuitry; alternatively, complex digital filters or advanced software algorithms can be designed to post-process the intermediate frequency signal obtained after mixing, filtering out or compensating for noise in the low-frequency region, such as flicker noise and slow-changing interference caused by ambient temperature drift.

[0004] In the process of implementing the embodiments of this disclosure, at least the following problems were found in the related art:

[0005] Both AC coupling and digital filtering in the relevant technical solutions are passive or post-compensation noise suppression methods. However, regardless of the subsequent filtering or compensation methods used, the mixing process itself dictates that for stationary or extremely low-speed targets, the effective intermediate frequency signal generated will inevitably be at or very close to the DC point. This means that the useful signal will inevitably fall into the region where the device itself has the most severe noise in the low-frequency range. Therefore, the system's signal processing always starts from an extremely low signal-to-noise ratio, resulting in a fundamental limitation on its sensitivity to weak signals (especially echoes from stationary or slightly moving targets), making it difficult to achieve a breakthrough improvement.

[0006] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0007] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0008] This disclosure provides a continuous wave radar detection method and apparatus, radar, and computer-readable storage medium to overcome the fundamental bottleneck in improving the system signal-to-noise ratio, avoid the situation where the echo signal of stationary or slightly moving targets falls into the DC and extremely low frequency regions after mixing, thereby enhancing the detection sensitivity of stationary or extremely low-speed slightly moving targets, and thus improving the detection capability of continuous wave radar devices for ultra-low-speed or slightly moving targets.

[0009] In some embodiments, the continuous wave radar detection method includes: generating an initial radio frequency carrier signal; applying a preset frequency offset to the initial radio frequency carrier signal to generate a transmitted signal; radiating the transmitted signal into the detection space via a transmitting antenna; receiving an echo signal formed by the reflection of the transmitted signal by a target in the detection space via a receiving antenna; mixing the echo signal with the initial radio frequency carrier signal to obtain a first intermediate frequency signal; wherein the preset frequency offset is configured such that for a stationary target, the first intermediate frequency signal is a signal with a frequency equal to a preset non-zero frequency value; and processing the first intermediate frequency signal to obtain information related to the state of the target.

[0010] Optionally, the first intermediate frequency signal is processed, including: passing the first intermediate frequency signal through a bandpass filter; wherein the center frequency of the bandpass filter is equal to a preset non-zero frequency value.

[0011] Optionally, it also includes setting the bandwidth of the bandpass filter according to the maximum Doppler frequency range of the target to be detected.

[0012] Optionally, it also includes: analyzing the noise characteristics in the DC and low-frequency regions of the receiving link; and determining a preset frequency offset value and a preset non-zero frequency value based on the noise characteristics.

[0013] Optionally, determining the preset frequency offset value and the preset non-zero frequency value based on noise characteristics includes: setting the preset non-zero frequency value to be greater than the flicker noise inflection point frequency of the receiving link.

[0014] Optionally, the preset non-zero frequency value is equal to the absolute value of the preset frequency offset.

[0015] Optionally, information related to the state of the target can be acquired, including: determining the existence state of the target; and / or determining the micro-motion state of the target; and / or determining the speed of the target's movement.

[0016] In some embodiments, the apparatus includes a processor and a memory storing program instructions, wherein the processor is configured to execute the continuous wave radar detection method described above when executing the program instructions.

[0017] In some embodiments, the radar includes: a radar body; and the aforementioned continuous wave radar detection device, which is mounted on the radar body.

[0018] In some embodiments, the computer-readable storage medium stores program instructions that, when executed, perform the continuous wave radar detection method described above.

[0019] The continuous wave radar detection method and apparatus, radar, and computer-readable storage medium provided in this disclosure can achieve the following technical effects: By applying a preset frequency offset to the initial RF carrier signal in the transmission link to generate the transmitted signal, and then mixing the received echo signal with this initial RF carrier signal (rather than the offset transmitted signal), the first intermediate frequency signal obtained after mixing for stationary targets has a preset non-zero frequency value. This method fundamentally changes the situation in traditional architectures where the echo signal from a stationary target falls into the DC and extremely low frequency regions after mixing, actively shifting the spectrum of the effective signal to a pre-set frequency point far from the high-noise, low-frequency region. Therefore, the system can avoid the useful signal being overwhelmed by severe background noise and slowly varying environmental interference at the beginning of signal processing, thereby significantly improving the signal-to-noise ratio and enhancing the detection sensitivity for stationary or extremely low-speed micro-moving targets.

[0020] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein: Figure 1 This is a schematic diagram of a radar provided in an embodiment of this disclosure; Figure 2 This is a schematic diagram of a continuous wave radar detection method provided in an embodiment of this disclosure; Figure 3 This is a schematic diagram of a continuous wave radar detection device provided in an embodiment of this disclosure.

[0022] Figure label: 10: Local oscillator; 20: Carrier frequency offset module; 30: Power amplifier; 40: Transmitting antenna; 50: Receiving antenna; 60: Low noise amplifier; 70: Mixer; 80: Intermediate frequency processing module; 800: Continuous wave radar detection device; 801: Processor; 802: Memory; 803: Communication interface; 804: Bus.

[0023] Specific implementation methods To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0024] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0025] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better description of the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of this disclosure according to the specific circumstances.

[0026] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0027] Unless otherwise stated, the term "multiple" means two or more.

[0028] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0029] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0030] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0032] Combination Figure 1 As shown, this disclosure presents a radar, including a local oscillator 10, a carrier frequency offset module 20, a transmitting antenna 40, a receiving antenna 50, a mixer 70, and an intermediate frequency (IF) processing module 80. The local oscillator 10 generates an initial radio frequency (RF) carrier signal; the carrier frequency offset module 20 is connected to the local oscillator 10 and applies a preset frequency offset to the initial RF carrier signal; the transmitting antenna 40 radiates the offset transmitted signal; the receiving antenna 50 receives the echo signal; the mixer 70 mixes the echo signal received by the receiving antenna 50 with the initial RF carrier signal generated by the local oscillator 10 to output an IF signal; the IF processing module 80 processes the IF signal to obtain target information; wherein the radar is configured such that for a stationary target, the center frequency of the IF signal is a preset non-zero frequency value. Optionally, the radar also includes a power amplifier 30, whose input is connected to the output of the carrier frequency offset module 20. Optionally, the radar also includes a low-noise amplifier 60, whose input is connected to the output of the receiving antenna 50. Optionally, the intermediate frequency processing module 80 includes a bandpass filter, the center frequency of which is equal to a preset non-zero frequency value. Optionally, the bandwidth of the bandpass filter is set based on the maximum Doppler frequency range of the target to be detected by the radar. Optionally, the carrier frequency offset module 20 includes a fixed frequency source and an offset mixer 70. Optionally, the fixed frequency source is a crystal oscillator, a phase-locked loop, or a direct digital frequency synthesizer. Optionally, the preset non-zero frequency value is equal to the absolute value of the preset frequency offset. Optionally, the local oscillator 10, the mixer 70, and the RF front-end circuit connecting the transmitting antenna 40 and the receiving antenna 50 are integrated into a single radar RF chip. Optionally, the radar also includes a processor electrically connected to the aforementioned electrical components for controlling their operation.

[0033] Figure 2 This is a schematic diagram of the continuous wave radar detection method provided in the embodiments of this disclosure. Any of the following methods can be executed in the radar or in a server or terminal device that is connected to the radar for communication.

[0034] Based on the radar structure described above, such as Figure 2 As shown, this disclosure provides a continuous wave radar detection method, including: S01, generate the initial radio frequency carrier signal.

[0035] S02, apply a preset frequency offset to the initial radio frequency carrier signal to generate a transmission signal.

[0036] S03 transmits the signal to the detection space via the transmitting antenna.

[0037] S04 receives the echo signal formed by the reflection of the transmitted signal by the target in the detection space through the receiving antenna.

[0038] S05, the echo signal is mixed with the initial radio frequency carrier signal to obtain the first intermediate frequency signal; wherein, the preset frequency offset is configured such that for a stationary target, the first intermediate frequency signal is a signal with a frequency equal to a preset non-zero frequency value.

[0039] S06, process the first intermediate frequency signal to obtain information related to the state of the target.

[0040] In this embodiment of the disclosure, the preset non-zero frequency value is set in the range of 100 kHz to 2 MHz.

[0041] In this embodiment, the initial radio frequency carrier signal is generated by a local oscillator, which includes a phase-locked loop frequency synthesizer or a direct digital frequency synthesizer. The phase-locked loop frequency synthesizer includes a reference crystal oscillator, a phase detector, a loop filter, and a voltage-controlled oscillator. The reference crystal oscillator generates a reference frequency signal. The phase detector compares the phase of the reference frequency signal with the phase of the output signal of the voltage-controlled oscillator and generates an error voltage. The loop filter filters out high-frequency components in the error voltage. The voltage-controlled oscillator adjusts its output frequency according to the filtered error voltage to generate the initial radio frequency carrier signal. The initial radio frequency carrier signal generated by the local oscillator is transmitted to the carrier frequency offset module and the mixer. The direct digital frequency synthesizer includes a phase accumulator, a waveform lookup table, and a digital-to-analog converter. The phase accumulator performs phase accumulation according to the frequency control word. The waveform lookup table stores sine wave amplitude information and outputs the corresponding amplitude code according to the phase accumulation result. The digital-to-analog converter converts the amplitude code into an analog signal and generates the initial radio frequency carrier signal through a low-pass filter. The initial radio frequency carrier signal generated by the local oscillator is transmitted to the carrier frequency offset module and the mixer. Specifically, the output frequency range of the phase-locked loop frequency synthesizer can be from 24 GHz to 77 GHz, and the output frequency range of the direct digital frequency synthesizer can also be from 24 GHz to 77 GHz. In other embodiments, the local oscillator includes a dielectric resonator oscillator or a crystal oscillator combined with a frequency multiplier chain. The dielectric resonator oscillator utilizes the frequency selection characteristics of the dielectric resonator and the amplification characteristics of the negative resistance device to generate an initial radio frequency carrier signal. The initial radio frequency carrier signal output by the dielectric resonator oscillator is transmitted to the carrier frequency offset module and the mixer via a buffer amplifier. The crystal oscillator combined with a frequency multiplier chain includes a crystal oscillator and a cascaded frequency multiplier. The crystal oscillator generates a fundamental frequency signal, and the cascaded frequency multiplier multiplies the fundamental frequency signal multiple times through a diode frequency multiplier circuit or a Gilbert unit frequency multiplier to generate the initial radio frequency carrier signal. The initial radio frequency carrier signal output by the crystal oscillator combined with the frequency multiplier chain is transmitted to the carrier frequency offset module and the mixer. Specifically, the operating frequency of the dielectric resonator oscillator can be 24 GHz, 60 GHz, or 77 GHz, the fundamental frequency of the crystal oscillator can be from 100 MHz to 1 GHz, and the frequency multiplication factor can be from 24 to 77.

[0042] In this embodiment, applying a preset frequency offset to the initial radio frequency carrier signal can be performed by a carrier frequency offset module. The carrier frequency offset module includes an analog mixing architecture or a direct digital frequency synthesizer architecture. The analog mixing architecture includes a single-frequency oscillator and a first mixer. The single-frequency oscillator generates an offset frequency signal, and the first mixer mixes the initial radio frequency carrier signal and the offset frequency signal to generate a transmission signal. The output of the carrier frequency offset module is connected to a power amplifier. The direct digital frequency synthesizer architecture includes a direct digital frequency synthesizer and an upconverter. The direct digital frequency synthesizer generates an offset frequency signal, and the upconverter mixes the initial radio frequency carrier signal and the offset frequency signal to generate a transmission signal. The output of the carrier frequency offset module is connected to a power amplifier. Specifically, the single-frequency oscillator can be a crystal oscillator or a voltage-controlled oscillator, the offset frequency can be from 100kHz to 2MHz, and the sampling clock frequency of the direct digital frequency synthesizer can be from 1GHz to 3GHz.

[0043] In this embodiment, the preset frequency offset is determined based on the DC and low-frequency noise characteristics of the receiving link. The preset frequency offset may be set to be greater than the flicker noise inflection point frequency of the receiving link, or set to be equal to the center frequency of the bandpass filter. The flicker noise inflection point frequency is determined by measuring the power spectral density of the output noise of the receiving link. The center frequency of the bandpass filter is set according to the expected intermediate frequency signal processing bandwidth. The preset frequency offset value is equal to a preset non-zero frequency value. Specifically, the preset frequency offset can be from 100 kHz to 2 MHz, the flicker noise inflection point frequency can be from 10 kHz to 100 kHz, and the deviation between the center frequency of the bandpass filter and the preset frequency offset can be less than 5%.

[0044] In this embodiment, the carrier frequency offset module applies a preset frequency offset to the initial radio frequency carrier signal via up-conversion or down-conversion. Up-conversion involves inputting the initial radio frequency carrier signal to the upper sideband input port of a single-sideband mixer, inputting the offset frequency signal to the local oscillator port of the single-sideband mixer, and outputting a sum-frequency signal as the transmit signal. Down-conversion involves inputting the initial radio frequency carrier signal to the lower sideband input port of the single-sideband mixer, inputting the offset frequency signal to the local oscillator port of the single-sideband mixer, and outputting a difference-frequency signal as the transmit signal. The transmit signal is then output to a power amplifier via the carrier frequency offset module. Specifically, the single-sideband mixer can be the aforementioned first mixer, and up-conversion or down-conversion can be achieved through different port configurations of the single-sideband mixer. The transmit signal frequency generated by up-conversion can be the sum of the initial radio frequency carrier signal frequency and the preset frequency offset, while the transmit signal frequency generated by down-conversion can be the difference between the initial radio frequency carrier signal frequency and the preset frequency offset. The sideband rejection ratio of the single-sideband mixer can be greater than 20dB.

[0045] In this embodiment, the transmitted signal is radiated to the detection space via a transmitting antenna through a transmitting link. The transmitting link includes a carrier frequency offset module, a power amplifier, and a transmitting antenna. The output of the power amplifier is connected to the input of the transmitting antenna. The transmitting antenna includes a microstrip patch antenna or a dipole antenna. The microstrip patch antenna includes a dielectric substrate, a metal patch, and a ground plane. The metal patch is printed on the front side of the dielectric substrate, and the ground plane covers the back side of the dielectric substrate. The metal patch is connected to the output of the power amplifier. The microstrip patch antenna radiates electromagnetic waves to the detection space through the electromagnetic field edge effect. The dipole antenna includes symmetrically arranged metal arms and a balun. The metal arms are connected to the balun, and the balun is connected to the output of the power amplifier. The dipole antenna radiates electromagnetic waves to the detection space through the current distribution of the metal arms. The detection space includes a monolithic microwave integrated circuit power amplifier or a multi-stage transistor power amplifier. The monolithic microwave integrated circuit power amplifier amplifies the transmitted signal output from the carrier frequency offset module and transmits it to the transmitting antenna. The multi-stage transistor power amplifier amplifies the transmitted signal output from the carrier frequency offset module through cascaded transistor amplifier stages and transmits it to the transmitting antenna. The connection between the transmitting antenna and the power amplifier can be direct or via a feeder network. Direct connection includes connecting the input port of the transmitting antenna and the output port of the power amplifier directly through a microstrip line. Feeder network connection includes connecting the transmitting antenna to the output port of the power amplifier through a microstrip line, stripline, or coaxial line. The detection space includes a fan-shaped area or an omnidirectional space area in front of the radar, with the main beam of the transmitting antenna pointing towards the center of the detection space. Specifically, the center frequency of the microstrip patch antenna can be 24GHz, 60GHz or 77GHz, the arm length of the dipole antenna can be one-quarter of the wavelength corresponding to the operating frequency, the output power of the monolithic microwave integrated circuit power amplifier can be 10dBm to 20dBm, the power gain of the multi-stage transistor power amplifier can be 20dB to 40dB, and the detection space distance range can be 0.1 meters to 100 meters.

[0046] In this embodiment, the echo signal formed by the reflection of the transmitted signal by a target in the detection space is received by a receiving antenna via a receiving link. The receiving link includes a receiving antenna and a low-noise amplifier. The output of the receiving antenna is connected to the input of the low-noise amplifier. The receiving antenna includes a microstrip patch antenna or a dipole antenna. The microstrip patch antenna includes a dielectric substrate, a metal patch, and a ground plane. The metal patch is printed on the front side of the dielectric substrate, and the ground plane covers the back side of the dielectric substrate. The metal patch is connected to the input of the low-noise amplifier. The dipole antenna includes symmetrically arranged metal arms and a balun. The metal arms are connected to the balun, and the balun is connected to the input of the low-noise amplifier. The receiving antenna and... The low-noise amplifier (LNO) can be connected via direct connection or through a feeder network. Direct connection involves directly connecting the receiving antenna output port to the LNO input port via a microstrip line. Feeder network connection involves connecting the receiving antenna to the LNO input port via a microstrip line, stripline, or coaxial line. Targets include stationary targets, moving targets, and slightly moving targets. Stationary targets reflect an echo signal with the same frequency as the transmitted signal. Moving targets reflect an echo signal with a Doppler frequency offset relative to the transmitted signal frequency. Slightly moving targets reflect an echo signal with a micro-Doppler frequency offset relative to the transmitted signal frequency. The echo signals are received by the receiving antenna and transmitted to the LNO for amplification. Specifically, the center frequency of the microstrip patch antenna can be 24 GHz, 60 GHz, or 77 GHz; the arm length of the dipole antenna can be one-quarter of the wavelength corresponding to the operating frequency; the noise figure of the LNO can be less than 3 dB; and the micro-Doppler frequency can be from 0.1 Hz to 10 Hz.

[0047] In this embodiment, the mixing of the echo signal and the initial RF carrier signal is achieved by a mixer, which includes a Gilbert unit mixer or a diode mixer. The mixer includes an RF input port, a local oscillator input port, and an intermediate frequency (IF) output port. The RF input port is connected to the output of a low-noise amplifier to receive the echo signal. The local oscillator input port is connected to the output of a local oscillator source to receive the initial RF carrier signal. The IF output port outputs a first IF signal. The Gilbert unit mixer converts the echo signal into a current signal through a transistor transconductance stage and performs switching mixing with the initial RF carrier signal generated by the local oscillator source to generate the first IF signal. The diode mixer mixes the echo signal with the initial RF carrier signal through the nonlinear diode characteristics to generate the first IF signal. The first IF signal includes a stationary target IF signal or a moving target IF signal. The frequency of the stationary target IF signal is equal to a preset non-zero frequency value, and the frequency of the moving target IF signal is equal to the sum or difference of the preset non-zero frequency value and the Doppler frequency. Specifically, the preset non-zero frequency value can be from 100KHz to 2MHz, the Doppler frequency can be from -100KHz to +100KHz, the frequency conversion loss of the mixer can be less than 10dB, and the input power of the local oscillator input port can be from -10dBm to +10dBm.

[0048] In this embodiment, the processing of the first intermediate frequency (IF) signal is achieved through an IF processing module. The IF processing module includes an analog signal processing circuit or a digital signal processing circuit. The analog signal processing circuit includes a bandpass filter, a detector, and a low-pass filter. The input of the bandpass filter is connected to the output of the mixer. The center frequency of the bandpass filter is equal to a preset non-zero frequency value, and the bandwidth of the bandpass filter covers the expected Doppler frequency range. The input of the detector is connected to the output of the bandpass filter. The detector includes an envelope detector or a synchronous detector. The envelope detector extracts the amplitude information of the first IF signal through diode rectification and RC filtering. The synchronous detector extracts the in-phase and quadrature components by multiplying the local reference signal with the first IF signal. The input of the low-pass filter is connected to the output of the detector. The low-pass filter outputs the signal after filtering out high-frequency residual components. Information related to the target's state; the digital signal processing circuit includes an analog-to-digital converter (ADC) and a digital signal processor (DSP). The ADC input is connected to the mixer output. The ADC converts the first intermediate frequency (IF) signal into a digital IF signal. The DSP includes a digital filter, a fast Fourier transform (FFT) module, and a target information extraction module. The digital filter performs bandpass filtering on the digital IF signal. The FFT module performs spectral analysis on the filtered digital IF signal. The target information extraction module obtains information related to the target's state based on the spectral characteristics. The target's state-related information includes its presence state, micro-motion state, or motion speed. The presence state includes whether the target is in the detection space or not. The micro-motion state includes breathing or heartbeat. The motion speed includes the target's radial motion speed value. Specifically, the center frequency of the bandpass filter can be from 100KHz to 2MHz, the bandwidth of the bandpass filter can be from 1KHz to 100KHz, the sampling rate of the analog-to-digital converter can be from 1MHz to 10MHz, the number of points of the fast Fourier transform module can be from 256 points to 4096 points, the respiratory state frequency range can be from 0.1Hz to 0.5Hz, the heartbeat state frequency range can be from 0.8Hz to 2Hz, and the radial motion velocity value can be from -200km / h to +200km / h.

[0049] The continuous wave radar detection method provided in this disclosure applies a preset frequency offset to the initial radio frequency carrier signal in the transmission link to generate a transmitted signal. The received echo signal is then mixed with this initial radio frequency carrier signal (rather than the offset transmitted signal), ensuring that for stationary targets, the frequency of the first intermediate frequency signal obtained after mixing is a preset non-zero frequency value. This method fundamentally changes the situation in traditional architectures where the echo signal from a stationary target falls into the DC and extremely low frequency regions after mixing. It actively shifts the spectrum of the effective signal to a pre-set frequency point far from the high-noise, low-frequency region. Therefore, the system can avoid the useful signal being overwhelmed by severe background noise and slowly varying environmental interference at the beginning of signal processing, thereby significantly improving the signal-to-noise ratio and enhancing the detection sensitivity for stationary or extremely low-speed micro-moving targets.

[0050] Optionally, the first intermediate frequency signal is processed, including: passing the first intermediate frequency signal through a bandpass filter; wherein the center frequency of the bandpass filter is equal to a preset non-zero frequency value.

[0051] In this embodiment, the bandpass filter includes a passive bandpass filter or an active bandpass filter. The passive bandpass filter includes an LC resonant filter or a ceramic filter. The LC resonant filter forms a resonant circuit through a series and parallel combination of inductors and capacitors to filter the first intermediate frequency signal in the frequency band near the center frequency. The ceramic filter uses the electromechanical coupling characteristics of piezoelectric ceramic materials to mechanically select the frequency of the first intermediate frequency signal. The input and output terminals of the LC resonant filter are respectively connected to the mixer output terminal and the subsequent signal processing circuit. The input and output terminals of the ceramic filter are respectively connected to the mixer output terminal and the subsequent signal processing circuit. The active bandpass filter includes a multiple feedback active filter or a bandpass RC active filter. The active feedback filter achieves bandpass transmission characteristics by forming multiple feedback paths through an operational amplifier and an RC network. The bandpass RC active filter achieves bandpass response characteristics by cascading an operational amplifier and an RC network. The input and output terminals of the multiple feedback active filter are connected to the mixer output and subsequent signal processing circuits, respectively. The center frequency of the bandpass filter is equal to a preset non-zero frequency value. The bandwidth of the bandpass filter is set according to the maximum Doppler frequency range. The bandwidth of the bandpass filter is equal to twice the absolute value of the maximum Doppler frequency range plus a protection bandwidth, or the bandwidth of the bandpass filter is equal to twice the absolute value of the maximum Doppler frequency range. Specifically, the preset non-zero frequency value can be from 100kHz to 2MHz, the maximum Doppler frequency range can be from -100kHz to +100kHz, the protection bandwidth can be from 0kHz to 50kHz, the quality factor of the LC resonant filter can be from 10 to 100, the bandwidth of the ceramic filter can be narrowband or wideband, and the center frequency gain of the multiple feedback active filter can be from 1 to 10.

[0052] In this way, during continuous wave radar detection, by configuring a preset frequency offset, the first intermediate frequency (IF) signal corresponding to a stationary target is at a preset non-zero frequency value, while the first IF signal of a moving target is distributed around this preset non-zero frequency value. The useful signal is concentrated in the frequency band near the preset non-zero frequency value. Passing the first IF signal through a bandpass filter with a center frequency equal to the preset non-zero frequency value allows signals in a specific frequency band near the center frequency to pass through. This selectively retains the useful signal concentrated near the preset non-zero frequency value while suppressing DC interference, low-frequency noise, and other irrelevant interference signals outside this frequency band. These interference signals, which might otherwise affect the identification of the useful signal, are reduced through this filtering process. This improves the signal-to-noise ratio of the first IF signal, making the subsequent acquisition of target state-related information more accurate, and thus helps to enhance the detection sensitivity of stationary or extremely low-speed micro-moving targets.

[0053] Optionally, it also includes setting the bandwidth of the bandpass filter according to the maximum Doppler frequency range of the target to be detected.

[0054] In this embodiment, the bandpass filter bandwidth is set according to the maximum Doppler frequency range of the target to be detected. The setting method includes setting based on the target's motion velocity range or setting based on the target's micro-motion frequency range. The target's maximum Doppler frequency range includes the maximum Doppler frequency range of a moving target or the maximum Doppler frequency range of a micro-motion target. Setting based on the target's motion velocity range includes calculating the absolute value of the maximum Doppler frequency based on the target's maximum radial velocity value and the radar operating wavelength, and setting the bandpass filter bandwidth to twice the absolute value of the maximum Doppler frequency. Setting based on the target's micro-motion frequency range includes considering respiratory motion... The first micro-Doppler frequency range caused by heartbeat and the second micro-Doppler frequency range caused by heartbeat determine the lower limit of the bandpass filter bandwidth, and the bandpass filter bandwidth is set to the combined bandwidth covering the first and second micro-Doppler frequency ranges. The bandpass filter bandwidth setting also includes adding a protection bandwidth, which is set on both sides of the base bandwidth to compensate for center frequency shifts caused by component parameter drift or temperature changes. The base bandwidth is twice the absolute value of the maximum Doppler frequency or the combined bandwidth. The bandpass filter bandwidth is equal to the sum of the base bandwidth and twice the protection bandwidth, or the bandpass filter bandwidth is equal to the base bandwidth. Specifically, the target's maximum radial velocity can be -200 km / h to +200 km / h, the radar operating wavelength can be 4 mm to 12.5 mm, the absolute value of the maximum Doppler frequency can be 0 Hz to 100 kHz, the base bandwidth can be 0 Hz to 200 kHz, the protection bandwidth can be 0 kHz to 20 kHz, the respiratory motion frequency can be 0.1 Hz to 0.5 Hz, and the heartbeat frequency can be 0.8 Hz to 2 Hz.

[0055] In this way, the center frequency of the bandpass filter is set to a preset non-zero frequency value. The first intermediate frequency signal of the moving target will deviate from this preset non-zero frequency value according to its own Doppler frequency. The target's speed determines the magnitude of the Doppler frequency, and the target's maximum Doppler frequency range defines the maximum possible range of this deviation. Setting the bandwidth of the bandpass filter according to the target's maximum Doppler frequency range ensures that the bandwidth of the bandpass filter precisely covers the signal frequency bands corresponding to all possible Doppler frequency deviations of the target. This avoids missing useful signals from moving targets due to an excessively narrow bandwidth, and also prevents the introduction of more out-of-band noise and interference beyond the target's Doppler frequency range due to an excessively wide bandwidth. Combined with the characteristic that the center frequency of the bandpass filter is consistent with the preset non-zero frequency value, this bandwidth setting can more accurately filter out useful signals containing target state information, further reduce the influence of irrelevant interference on the signal, improve the signal-to-noise ratio, and make subsequent acquisition of information such as the target's presence state, micro-motion state, or speed more accurate. At the same time, it enhances the radar's adaptability to targets with different speeds and improves the overall detection effect of the radar.

[0056] Optionally, it also includes: analyzing the noise characteristics in the DC and low-frequency regions of the receiving link; and determining a preset frequency offset value and a preset non-zero frequency value based on the noise characteristics.

[0057] In this embodiment, the noise characteristics in the DC and low-frequency regions of the receiving link are analyzed through a noise analysis module or a manual calibration procedure. The receiving link includes a receiving antenna and a low-noise amplifier. The noise analysis module includes a spectrum analysis unit or a power detection unit. The spectrum analysis unit measures the noise power spectral density distribution at the output of the receiving link in the low-frequency region to identify the flicker noise inflection point frequency. The power detection unit measures the noise power level of the receiving link in the DC and low-frequency regions to determine the noise floor height. The manual calibration procedure includes measuring the noise parameters of the receiving link using external testing instruments and inputting the measurement results into the system configuration. The noise characteristics include flicker noise characteristics, thermal noise characteristics, or DC offset characteristics. The flicker noise characteristics show that the noise power spectral density changes inversely with the frequency, while the thermal noise characteristics show that the noise power spectral density is flat in the frequency domain. The DC offset characteristic is manifested as the voltage offset at zero frequency. Determining the preset frequency offset value and the preset non-zero frequency value based on noise characteristics includes setting the preset frequency offset value to be greater than the flicker noise inflection point frequency, and setting the preset non-zero frequency value to be equal to the preset frequency offset value or equal to the absolute value of the preset frequency offset value. The preset frequency offset value is implemented by the carrier frequency offset module. The preset non-zero frequency value is the first intermediate frequency signal frequency corresponding to the stationary target. The flicker noise inflection point frequency is the frequency value where the flicker noise power spectral density is equal to the thermal noise power spectral density. The preset frequency offset value and the preset non-zero frequency value are determined by a lookup table method or an iterative optimization method. The lookup table method selects the preset frequency offset value according to a pre-established table of correspondence between noise characteristics and optimal frequency offset. The iterative optimization method determines the optimal preset frequency offset value by scanning different frequency offset values ​​and comparing the output signal-to-noise ratio. Specifically, the flicker noise inflection point frequency can be from 10KHz to 100KHz, the preset frequency offset value can be from 100KHz to 2MHz, the thermal noise power spectral density can be -174dBm / Hz, the DC offset voltage can be from 0.1mV to 10mV, and the signal-to-noise ratio comparison bandwidth can be from 1KHz to 100KHz.

[0058] Thus, in continuous wave radar detection, the DC and low-frequency regions of the receiving link suffer from significant noise interference, and the noise distribution and intensity vary among different receiving links. This noise negatively impacts subsequent signal processing and target detection. By analyzing the noise characteristics of the DC and low-frequency regions in the receiving link, the range of frequency bands with severe noise and the location of relatively low-noise frequency bands can be identified. Based on these clearly defined noise characteristics, a preset frequency offset value and a preset non-zero frequency value can be determined. This allows the preset non-zero frequency value to accurately avoid the frequency bands with severe noise and fall into regions with lower noise levels. The preset frequency offset is configured so that the first intermediate frequency signal frequency of a stationary target equals the preset non-zero frequency value. This allows the first intermediate frequency signal corresponding to the stationary target to be more effectively moved away from high-noise regions, reducing noise interference with useful signals and further improving the signal-to-noise ratio of the first intermediate frequency signal. This provides a more favorable signal foundation for subsequent processing to obtain target state-related information, thereby better enhancing the detection sensitivity for stationary or extremely low-speed micro-moving targets. At the same time, the setting of the preset frequency offset value and the preset non-zero frequency value is more closely aligned with the actual situation of the specific receiving link, improving the adaptability of the solution.

[0059] Optionally, determining the preset frequency offset value and the preset non-zero frequency value based on noise characteristics includes: setting the preset non-zero frequency value to be greater than the flicker noise inflection point frequency of the receiving link.

[0060] In this embodiment, setting a preset non-zero frequency value greater than the flicker noise inflection point frequency of the receiving link is achieved through noise measurement or theoretical calculation. The noise measurement method includes measuring the noise power spectral density curve at the output of the mixer or the output of the low-noise amplifier in the receiving link to determine the flicker noise inflection point frequency, and setting the preset non-zero frequency value to a preset multiple of the flicker noise inflection point frequency, which includes 1.5 times to 10 times. The theoretical calculation method includes calculating the flicker noise inflection point frequency based on the process parameters and bias conditions of the low-noise amplifier and the mixer, and setting the preset non-zero frequency value to the flicker noise inflection point frequency plus a fixed frequency margin, which includes 50KHz to 500KHz. The preset non-zero frequency value is a method of determining the preset non-zero frequency value. The flicker noise inflection point frequency is a key parameter in the noise characteristics of the receiving link, and the receiving link includes a receiving antenna and a low-noise amplifier. Specifically, the flicker noise inflection point frequency can be from 10KHz to 100KHz, the preset non-zero frequency value can be from 100KHz to 2MHz, the preset multiplier can be from 2 to 5 times, and the fixed frequency margin can be from 100KHz to 300KHz.

[0061] Thus, in continuous wave radar detection, scintillation noise in the receiving link is more severe in the low-frequency region, and the inflection point frequency of scintillation noise is the dividing point where its intensity significantly decreases; noise in the frequency band below the inflection point frequency has a more prominent impact. When determining the preset frequency offset and preset non-zero frequency values ​​based on the noise characteristics of the receiving link, setting the preset non-zero frequency value to be greater than the scintillation noise inflection frequency ensures that the first intermediate frequency signal corresponding to a stationary target is in a frequency band with lower scintillation noise intensity, preventing the useful signal from falling into the high-noise region below the inflection point frequency. This setting, combined with the preset frequency offset configuration, can further reduce the interference of scintillation noise on the first intermediate frequency signal, helping to improve the signal-to-noise ratio and creating more favorable conditions for subsequent processing of the first intermediate frequency signal and obtaining target status-related information, thereby enhancing the detection sensitivity for stationary or extremely low-speed micro-moving targets.

[0062] Optionally, the preset non-zero frequency value is equal to the absolute value of the preset frequency offset.

[0063] In this embodiment, the preset non-zero frequency value is equal to the absolute value of the preset frequency offset. The preset frequency offset includes an up-conversion offset value or a down-conversion offset value. The up-conversion offset value is a positive frequency value, and the down-conversion offset value is a negative frequency value. The mathematical determination method of the preset non-zero frequency value includes taking the absolute value of the preset frequency offset. When the carrier frequency offset module applies an up-conversion offset value to the initial radio frequency carrier signal, the transmitted signal frequency is equal to the sum of the initial radio frequency carrier signal frequency and the up-conversion offset value. After the mixer mixes the echo signal and the initial radio frequency carrier signal, the first intermediate frequency signal frequency is equal to the up-conversion offset value, and the preset non-zero frequency value is equal to the up-conversion offset value. When the carrier frequency offset module applies a down-conversion offset value to the initial radio frequency carrier signal, the transmitted signal frequency is equal to the difference between the initial radio frequency carrier signal frequency and the down-conversion offset value. Here, the down-conversion offset value is negative. After the mixer mixes the echo signal and the initial radio frequency carrier signal, the first intermediate frequency signal frequency is equal to the absolute value of the down-conversion offset value, and the preset non-zero frequency value is equal to the absolute value of the down-conversion offset value. Specifically, the upconversion offset value can be +100KHz to +2MHz, the downconversion offset value can be -2MHz to -100KHz, and the preset non-zero frequency value can be 100KHz to 2MHz.

[0064] In this way, the transmitted signal is generated by applying the preset frequency offset to the initial radio frequency carrier signal. When the echo signal of the stationary target is mixed with the initial radio frequency carrier signal, the frequency of the intermediate frequency signal is numerically equal to the absolute value of the offset. Therefore, this setting ensures the direct correspondence between system parameters, so that the center frequency of the intermediate frequency signal generated for the stationary target is deterministically controlled at the preset non-zero value. This simplifies the subsequent configuration of the center frequency of the bandpass filter and helps to avoid signal spectrum splitting or signal-to-noise ratio reduction problems that may be caused by inconsistent frequency relationships. It stably achieves the effect of moving the signal away from the high noise area.

[0065] Optionally, information related to the state of the target can be acquired, including: determining the existence state of the target; and / or determining the micro-motion state of the target; and / or determining the speed of the target's movement.

[0066] In this embodiment, information related to the target's state is acquired through a target information extraction module. This module includes a presence state detection unit, a micro-motion state analysis unit, or a motion speed calculation unit. The presence state detection unit determines the target's presence state by comparing the amplitude of a first intermediate frequency signal with a preset presence threshold. If the amplitude of the first intermediate frequency signal is greater than the preset presence threshold, the target is determined to exist within the detection space; if the amplitude of the first intermediate frequency signal is less than or equal to the preset presence threshold, the target is determined not to exist within the detection space. The preset presence threshold is set based on the received link noise floor power. The micro-motion state analysis unit determines the target's micro-motion state by performing spectral analysis on the first intermediate frequency signal. The micro-motion state includes respiratory and heartbeat states. The respiratory state is determined by identifying spectral peaks in the 0.1Hz to 0.5Hz frequency band, and the heartbeat state is determined by identifying spectral peaks in the 0.8Hz to 2Hz frequency band. The motion speed calculation unit determines the target's motion speed by measuring the frequency difference between the first intermediate frequency signal frequency and a preset non-zero frequency value. The frequency difference is equal to the Doppler frequency, and the motion speed is equal to half the product of the Doppler frequency and the radar operating wavelength. The radar operating wavelength is determined by the initial radio frequency carrier signal frequency. Information related to the target's state includes presence, micro-motion, or motion speed. Presence includes whether the target is in the detection space or not. Specifically, the preset presence threshold can be 3dB to 20dB of the noise floor power, the spectrum analysis can use Fast Fourier Transform or Short-Time Fourier Transform, the radar operating wavelength in the motion speed calculation can be 4mm to 12.5mm, and the frequency difference measurement accuracy can be 1Hz to 100Hz.

[0067] In continuous wave radar detection, by applying a preset frequency offset to the initial radio frequency carrier signal, the echo signal is mixed with the initial radio frequency carrier signal to obtain the first intermediate frequency (IF) signal. After processing by a bandpass filter, the effective signal is far removed from the DC and low-frequency noise regions, significantly improving the signal-to-noise ratio and making the characteristics of the useful signal more clearly discernible. Regarding the target's presence, regardless of whether the target is stationary, slightly moving, or in motion, it will reflect the transmitted signal to form an echo. The processed IF signal will exhibit characteristics corresponding to the target's reflection, allowing the determination of the target's presence in the detection space. For the target's slightly moving state, the slightly moving target will cause a small frequency change in the echo signal. This change will be reflected in the IF signal. The aforementioned signal processing method reduces the masking of weak signals by noise, allowing this small change to be identified, thus determining the target's slightly moving state. Regarding the target's velocity, the moving target will cause a Doppler frequency shift, causing the IF signal to shift accordingly around a preset non-zero frequency value. A clear IF signal can accurately reflect this shift, and the target's velocity can be deduced based on this shift information.

[0068] Optionally, applying a preset frequency offset to the initial radio frequency carrier signal includes: increasing the frequency of the initial radio frequency carrier signal by a preset frequency offset value through upconversion; or decreasing the frequency of the initial radio frequency carrier signal by a preset frequency offset value through downconversion.

[0069] In this embodiment, the selection of up-conversion or down-conversion mode is determined based on the radar operating frequency band and spectrum occupancy. Up-conversion mode is suitable for setting the transmitted signal frequency above the initial radio frequency carrier signal frequency to avoid low-frequency interference, while down-conversion mode is suitable for setting the transmitted signal frequency below the initial radio frequency carrier signal frequency to avoid high-frequency interference. Up-conversion mode sets the transmitted signal frequency to the sum of the initial radio frequency carrier signal frequency and a preset frequency offset value through a carrier frequency offset module, while down-conversion mode sets the transmitted signal frequency to the difference between the initial radio frequency carrier signal frequency and the preset frequency offset value through a carrier frequency offset module. The preset frequency offset value is positive in both up-conversion and down-conversion modes. Up-conversion and down-conversion modes are implementation methods for applying a preset frequency offset to the initial radio frequency carrier signal. The carrier frequency offset module includes a circuit for performing up-conversion mode or a circuit for performing down-conversion mode. Specifically, the initial radio frequency carrier signal frequency can be 24 GHz, 60 GHz or 77 GHz, the preset frequency offset value can be 100 kHz to 2 MHz, the transmission signal frequency under up-conversion mode can be 24.1 GHz to 77.002 GHz, and the transmission signal frequency under down-conversion mode can be 23.998 GHz to 76.9 GHz.

[0070] Thus, in continuous wave radar detection, applying a preset frequency offset to the initial radio frequency carrier signal is a crucial prerequisite for configuring the first intermediate frequency (IF) signal of a stationary target to a preset non-zero frequency value, away from DC and high-noise low-frequency regions. Two flexible and feasible implementation paths are provided: increasing the preset frequency offset by up-conversion or decreasing it by down-conversion. Both methods can accurately achieve the preset frequency offset configuration requirements. Regardless of the method chosen, the transmitted signal and the initial radio frequency carrier signal will form a preset frequency difference. This allows the echo signal from the stationary target to be mixed with the initial radio frequency carrier signal to obtain a first IF signal with a preset non-zero frequency value, preventing the useful signal from falling into the low-frequency, high-noise region. Furthermore, the diverse implementation methods can adapt to the hardware design requirements and operating frequency band characteristics of different radar systems, without being limited by a single frequency conversion method. This ensures stable active shifting of the effective signal spectrum in various application scenarios, helping to reduce the impact of background noise and slowly varying environmental interference on the useful signal and improve the signal-to-noise ratio.

[0071] Combination Figure 3 As shown, this disclosure provides a continuous wave radar detection device 800, including a processor 801 and a memory 802. Optionally, the device may further include a communication interface 803 and a bus 804. The processor 801, communication interface 803, and memory 802 can communicate with each other via the bus 804. The communication interface 803 can be used for information transmission. The processor 801 can call logical instructions in the memory 802 to execute the continuous wave radar detection method of the above embodiment.

[0072] Furthermore, the logic instructions in the aforementioned memory 802 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0073] The memory 802, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 801 executes functional applications and data processing by running the program instructions / modules stored in the memory 802, thereby implementing the continuous wave radar detection method in the above embodiments.

[0074] The memory 802 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 802 may include high-speed random access memory and may also include non-volatile memory.

[0075] This disclosure provides a radar system, including a radar body and the aforementioned continuous wave radar detection device 800. The continuous wave radar detection device 800 is mounted on the radar body. The mounting relationship described herein is not limited to placement inside the radar, but also includes mounting connections with other radar components, including but not limited to physical connections, electrical connections, or signal transmission connections. Those skilled in the art will understand that the continuous wave radar detection device 800 can be adapted to suitable radar bodies to achieve other feasible embodiments.

[0076] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to perform the aforementioned continuous wave radar detection method.

[0077] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code.

[0078] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0079] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0080] The methods and products disclosed in the embodiments herein (including but not limited to devices and equipment) can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to implement this embodiment according to actual needs. In addition, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0081] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A continuous wave radar detection method, characterized in that, include: Generate the initial radio frequency carrier signal; A preset frequency offset is applied to the initial radio frequency carrier signal to generate the transmitted signal; The transmitted signal is radiated into the detection space via the transmitting antenna; The echo signal is received by the receiving antenna, which is formed by the reflection of the transmitted signal by the target in the detection space. The echo signal is mixed with the initial radio frequency carrier signal to obtain the first intermediate frequency signal; wherein, the preset frequency offset is configured such that for a stationary target, the first intermediate frequency signal is a signal with a frequency equal to a preset non-zero frequency value. The first intermediate frequency signal is processed to obtain information related to the state of the target.

2. The method according to claim 1, characterized in that, The first intermediate frequency signal is processed, including: The first intermediate frequency signal is passed through a bandpass filter; wherein the center frequency of the bandpass filter is equal to a preset non-zero frequency value.

3. The method according to claim 2, characterized in that, Also includes: Set the bandwidth of the bandpass filter according to the maximum Doppler frequency range of the target to be detected.

4. The method according to any one of claims 1 to 3, characterized in that, Also includes: Analyze the noise characteristics in the DC and low-frequency regions of the receiving link; Based on noise characteristics, a preset frequency offset value and a preset non-zero frequency value are determined.

5. The method according to claim 4, characterized in that, Determining the preset frequency offset value and the preset non-zero frequency value based on noise characteristics includes: Set the preset non-zero frequency value to be greater than the flicker noise inflection point frequency of the receiving link.

6. The method according to any one of claims 1 to 3, characterized in that, The preset non-zero frequency value is equal to the absolute value of the preset frequency offset.

7. The method according to any one of claims 1 to 3, characterized in that, Obtain information related to the state of the target, including: Determine the existence status of the target; and / or, Determine the micro-motion state of the target; and / or, Determine the target's speed.

8. A continuous wave radar detection device, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to execute the continuous wave radar detection method as described in any one of claims 1 to 7 when running the program instructions.

9. A radar, characterized in that, include: Radar body; as well as, The continuous wave radar detection device as described in claim 8 is installed on the radar body.

10. A computer-readable storage medium storing program instructions, characterized in that, When the program instructions are executed, they cause the computer to perform the continuous wave radar detection method as described in any one of claims 1 to 7.

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