frequency modulated continuous wave radar

Abstract

Various embodiments of this disclosure relate to frequency-modulated continuous wave (FM-CVW) radar. According to some embodiments of this disclosure, an electronic circuit is provided that mixes a signal having at least a fundamental signal component with an FM-CVW signal to obtain a swept-frequency signal having multiple parallel FM-CVW signal components, thereby dividing the entire swept-frequency bandwidth of the FM-CVW radar system into multiple parallel small bandwidths. In this way, the electronic circuit according to this disclosure can not only achieve both high swept-frequency bandwidth and low swept-frequency period, but also reduce the number of required transmit and receive radio frequency channels, thereby reducing hardware costs.

Description

Technical Field

[0001] This disclosure generally relates to the field of circuits, and more specifically, to frequency modulated continuous wave radar. Background Technology

[0002] With the development of autonomous driving technology, an increasing number of sensors are being used in autonomous driving systems, such as high-definition cameras, LiDAR, and millimeter-wave radar. Millimeter-wave radar is suitable for all-weather operation and can be used in short-, medium-, and long-range applications. Frequency Modulated Continuous Wave (FMCW) radar is a commonly used operating mode for millimeter-wave radar. In operation, FMCW radar transmits FMCW signals with frequencies varying over time and receives echo signals corresponding to the transmitted FMCW signals. Target localization and relative velocity measurement can be performed by utilizing the difference between the echo signal frequency and the transmitted signal frequency.

[0003] High-performance FMCW radars require high range resolution and the ability to measure higher velocities. This means that the design must balance high sweep bandwidth and low sweep period. This presents a challenge to the hardware design of the radar system. Conventional designs use multiple radar transceivers to increase the sweep bandwidth while maintaining the sweep period, but this leads to a significant increase in hardware costs. Summary of the Invention

[0004] In view of the above problems, the embodiments of this disclosure are intended to provide an electronic circuit and electronic device for reducing the hardware cost of a radar system.

[0005] According to a first aspect of this disclosure, an electronic circuit is provided, comprising: an FMCW signal generator configured to generate an FMCW signal; a spread spectrum device configured to generate a spread spectrum signal based on the FMCW signal, the spread spectrum signal including a first group of signal components and a second group of signal components, the sweep bandwidth and sweep period of the first group of signal components and the second group of signal components being the same as those of the FMCW signal, and the frequency band of the first group of signal components being not lower than that of the second group of signal components; a transmitter configured to transmit the spread spectrum signal; a receiver configured to receive an echo signal associated with the transmitted spread spectrum signal, the echo signal including the first group of signal components and the second group of signal components; and an echo signal processing device configured to determine the frequency difference between the current FMCW signal of the FMCW signal generator and the first group of signal components and the second group of signal components of the echo signal, respectively. With this configuration, the entire sweep bandwidth of the FMCW radar system can be divided into multiple parallel small bandwidths by means of a spread spectrum signal that includes multiple parallel FMCW signal components. This allows the electronic circuit according to the present disclosure to not only achieve both high sweep bandwidth and low sweep period, but also to reduce the number of required transmit and receive radio frequency channels, thereby reducing hardware costs.

[0006] In some implementations, the spread spectrum device includes: a first signal generator configured to generate a first signal, the first signal including a fundamental frequency signal component; and an up-conversion device configured to up-convert the first signal using an FMCW signal to generate a spread spectrum signal, the spread spectrum signal consisting of a first set of signal components and a second set of signal components, the first set of signal components having a frequency greater than the frequency of the FMCW signal and including the sum of the frequency of the FMCW signal and the frequency of the fundamental frequency signal component, the second set of signal components having a frequency less than the frequency of the FMCW signal and including the difference between the frequency of the FMCW signal and the frequency of the fundamental frequency signal component; wherein the frequency of the fundamental frequency signal component is greater than or equal to half the sweep bandwidth of the FMCW signal. With this configuration, the spread spectrum device can generate a spread spectrum signal comprising multiple parallel FMCW signal components based on the FMCW signal, thereby dividing the entire sweep bandwidth of the FMCW radar system into multiple parallel small bandwidths to balance high sweep bandwidth and low sweep period. Compared to conventional solutions, the electronic circuit based on this implementation method can increase the sweep bandwidth without increasing the sweep period by using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0007] In some implementations, the echo signal processing apparatus includes: a first signal processing unit configured to extract a first set of signal components from the echo signal and generate a first set of intermediate frequency (IF) signals based on the first set of signal components, the current FMCW signal, and the first signal, wherein the frequency of each IF signal in the first set indicates the frequency difference between the current FMCW signal and a corresponding signal component in the first set of signal components in the echo signal; and a second signal processing unit configured to extract a second set of signal components from the echo signal and generate a second set of IF signals based on the second set of signal components, the current FMCW signal, and the first signal, wherein the frequency of each IF signal in the second set indicates the frequency difference between the current FMCW signal and a corresponding signal component in the second set of signal components in the echo signal. With this configuration, the echo signal processing apparatus can process the first set of signal components and the second set of signal components in the echo signal separately, thereby determining the frequency difference between the current FMCW signal of the FMCW signal generator and each signal component in the echo signal for use in ranging and / or speed measurement. Compared to conventional solutions, the electronic circuit based on this implementation method can increase the sweep bandwidth without increasing the sweep period by using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0008] In some implementations, the first signal processing apparatus includes: a first dechirping device configured to extract a first set of signal components from the echo signal and dechirp the first set of signal components in the echo signal using a current FMCW signal to obtain a first dechirped signal; a first downconversion device configured to downconvert the first dechirped signal using each signal component in the first signal to obtain a first set of downconverted signals; and a first filtering device configured to perform low-pass filtering on the first set of downconverted signals to obtain a first set of intermediate frequency signals. The second signal processing device includes: a second dechirping device configured to extract a second set of signal components from the echo signal and dechirp the second set of signal components in the echo signal using the current FMCW signal to obtain a second dechirped signal; a second down-conversion device configured to down-convert the second dechirped signal using each signal component in the first signal to obtain a second set of down-converted signals; and a second filtering device configured to low-pass filter the second set of down-converted signals to obtain a second set of intermediate frequency (IF) signals. With this configuration, the first and second sets of signal components in the echo signal can be processed separately, thereby determining multiple IF signals that respectively indicate the frequency difference between the current FMCW signal and each frequency component in the echo signal for use in ranging and / or speed measurement. Compared to conventional solutions, the electronic circuitry according to this implementation can increase the sweep bandwidth without increasing the sweep period using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0009] In some implementations, the spread spectrum device includes: a first signal generator configured to generate a first signal, the first signal including a fundamental signal component and harmonic signal components; and an up-conversion device configured to up-convert the first signal using an FMCW signal to generate a spread spectrum signal, the spread spectrum signal consisting of a first set of signal components and a second set of signal components, the first set of signal components having a frequency greater than the frequency of the FMCW signal and including the sum of the frequencies of the harmonic signals and the FMCW signal, the second set of signal components having a frequency greater than the frequency of the FMCW signal and including the sum of the frequencies of the fundamental signal component and the FMCW signal; wherein the frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal. With this configuration, the spread spectrum device can generate a spread spectrum signal comprising multiple parallel FMCW signal components based on the FMCW signal, thereby dividing the entire sweep bandwidth of the FMCW radar system into multiple parallel small bandwidths to balance high sweep bandwidth and low sweep period. Compared to conventional solutions, the electronic circuit based on this implementation method can increase the sweep bandwidth without increasing the sweep period by using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0010] In some implementations, the spread spectrum device includes: a first signal generator configured to generate a first signal, the first signal including a fundamental signal component and harmonic signal components; and an up-conversion device configured to up-convert the first signal using an FMCW signal to generate a spread spectrum signal, the spread spectrum signal consisting of a first set of signal components and a second set of signal components, the first set of signal components having a frequency lower than the frequency of the FMCW signal and including the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component, the second set of signal components having a frequency lower than the frequency of the FMCW signal and including the difference between the frequency of the FMCW signal and the frequency of the harmonic signal; wherein the frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal. With this configuration, the spread spectrum device can generate a spread spectrum signal comprising multiple parallel FMCW signal components based on the FMCW signal, thereby dividing the entire sweep bandwidth of the FMCW radar system into multiple parallel small bandwidths to balance high sweep bandwidth and low sweep period. Compared to conventional solutions, the electronic circuit based on this implementation method can increase the sweep bandwidth without increasing the sweep period by using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0011] In some implementations, the echo signal processing apparatus includes: a dechirping device configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal; a down-conversion device configured to down-convert the dechirped signal using each signal component of the first signal to obtain a set of down-converted signals; and a filtering device configured to perform low-pass filtering on the set of down-converted signals to obtain a set of intermediate frequency (IF) signals, wherein the frequency of each IF signal in the set of IF signals indicates the frequency difference between the corresponding signal component in the current FMCW signal and the echo signal. With this configuration, the obtained set of IF signals can be used for ranging and / or speed measurement. Compared to conventional solutions, the electronic circuitry according to this implementation can increase the sweep bandwidth without increasing the sweep period by using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0012] In some implementations, the spread spectrum device includes: a first signal generator configured to generate a first signal, the first signal including a fundamental signal component having a first frequency; and an up-conversion device configured to up-convert the first signal using an FMCW signal to generate a spread spectrum signal, the spread spectrum signal consisting of a first set of signal components and a second set of signal components, the first set of signal components having a frequency greater than the frequency of the FMCW signal and including the sum of the frequency of the FMCW signal and the frequency of the fundamental signal component, the second set of signal components having a frequency equal to the frequency of the FMCW signal; wherein the frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal. With this configuration, the spread spectrum device can generate a spread spectrum signal comprising multiple parallel FMCW signal components based on the FMCW signal, thereby dividing the entire sweep bandwidth of the FMCW radar system into multiple parallel small bandwidths to balance high sweep bandwidth and low sweep period. Compared to conventional solutions, the electronic circuitry according to this implementation can use only one transmit RF channel and one receive RF channel to increase the sweep bandwidth without increasing the sweep period, thereby reducing hardware costs.

[0013] In some implementations, the echo signal processing apparatus includes: a dechirping device configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal; a down-conversion device configured to down-convert the dechirped signal using each signal component of the first signal to obtain a set of down-converted signals; a first filtering device configured to low-pass filter the set of down-converted signals to obtain a first set of intermediate frequency (IF) signals, wherein the frequency of each IF signal in the first set indicates the frequency difference between the current FMCW signal and a corresponding signal component in the first set of signal components in the echo signal; and a second filtering device configured to low-pass filter the dechirped signals to obtain a local oscillator (LO) IF signal, wherein the frequency of the LO IF signal indicates the frequency difference between the current FMCW signal and a second set of signal components in the echo signal. With this configuration, ranging and / or speed measurement can be performed using the obtained set of IF signals and the LO IF signal. Compared to conventional solutions, the electronic circuit based on this implementation method can increase the sweep bandwidth without increasing the sweep period by using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0014] In some implementations, the spread spectrum device includes: a first signal generator configured to generate a first signal, the first signal including a fundamental signal component having a first frequency; and an up-conversion device configured to up-convert the first signal using an FMCW signal to generate a spread spectrum signal, the spread spectrum signal consisting of a first set of signal components and a second set of signal components, the frequency of the first set of signal components being the frequency of the FMCW signal, and the frequency of the second set of signal components being less than the frequency of the FMCW signal and including the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component; wherein the frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal. With this configuration, the spread spectrum device can generate a spread spectrum signal comprising multiple parallel FMCW signal components based on the FMCW signal, thereby dividing the entire sweep bandwidth of the FMCW radar system into multiple parallel small bandwidths to balance high sweep bandwidth and low sweep period. Compared to conventional solutions, the electronic circuitry according to this implementation can use only one transmit RF channel and one receive RF channel to increase the sweep bandwidth without increasing the sweep period, thereby reducing hardware costs.

[0015] In some implementations, the echo signal processing apparatus includes: a dechirping device configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal; a down-conversion device configured to down-convert the dechirped signal using each signal component of the first signal to obtain a set of down-converted signals; a first filtering device configured to perform low-pass filtering on the set of down-converted signals to obtain a first set of intermediate frequency (IF) signals, wherein the frequency of each IF signal in the first set of IF signals indicates the frequency difference between the current FMCW signal and a corresponding signal component in a second set of signal components in the echo signal; and a second filtering device configured to perform low-pass filtering on the dechirped signals to obtain a local oscillator (LO) IF signal, wherein the frequency of the LO IF signal indicates the frequency difference between the current FMCW signal and the second set of signal components in the echo signal. With this configuration, ranging and / or speed measurement can be performed using the obtained set of IF signals and the LO IF signal. Compared to conventional solutions, the electronic circuit based on this implementation method can increase the sweep bandwidth without increasing the sweep period by using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0016] In some implementations, the spread spectrum device includes: a first signal generator configured to generate a first signal, the first signal including a fundamental frequency signal component; and an up-conversion device configured to up-convert the first signal using an FMCW signal to generate a spread spectrum signal, the spread spectrum signal consisting of a local oscillator signal component, a first set of signal components, and a second set of signal components. The frequency of the local oscillator signal component is the frequency of the FMCW signal. The frequency of the first set of signal components is greater than the frequency of the FMCW signal and includes the sum of the frequency of the FMCW signal and the frequency of the fundamental frequency signal component. The frequency of the second set of signal components is less than the frequency of the FMCW signal and includes the difference between the frequency of the FMCW signal and the frequency of the fundamental frequency signal component. The frequency of the fundamental frequency signal component is greater than or equal to the sweep bandwidth of the FMCW signal. With this configuration, the spread spectrum device can generate a spread spectrum signal including multiple parallel FMCW signal components based on the FMCW signal, thereby dividing the entire sweep bandwidth of the FMCW radar system into multiple parallel small bandwidths to balance high sweep bandwidth and low sweep period. Compared to conventional solutions, the electronic circuit based on this implementation method can increase the sweep bandwidth without increasing the sweep period by using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0017] In some implementations, the echo signal processing apparatus includes: a local oscillator signal processing apparatus configured to generate a local oscillator intermediate frequency (IF) signal based on the echo signal, a current FMCW signal, and a first signal, wherein the frequency of the IF signal indicates the frequency difference between the current FMCW signal and the local oscillator signal component in the echo signal; a first signal processing apparatus configured to extract a first set of signal components from the echo signal and generate a first set of IF signals based on the first set of signal components, the current FMCW signal, and the first signal, wherein the frequency of each IF signal in the first set of IF signals indicates the frequency difference between the current FMCW signal and a corresponding signal component in the first set of signal components in the echo signal; and a second signal processing apparatus configured to extract a second set of signal components from the echo signal and generate a second set of IF signals based on the second set of signal components, the current FMCW signal, and the first signal, wherein the frequency of each IF signal in the second set of IF signals indicates the frequency difference between the current FMCW signal and a corresponding signal component in the second set of signal components in the echo signal. With this configuration, the echo signal processing device can process the local oscillator signal component, the first group of signal components, and the second group of signal components in the echo signal separately. This allows for the determination of the frequency difference between the current FMCW signal from the FMCW signal generator and each signal component in the echo signal, which can then be used for ranging and / or speed measurement. Compared to conventional solutions, the electronic circuitry based on this implementation can achieve increased sweep bandwidth without increasing the sweep period using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0018] In some implementations, the local oscillator signal processing apparatus includes: a local oscillator dechirping device configured to dechirp the echo signal using the current FMCW signal to obtain a local oscillator dechirped signal; and a local oscillator filtering device configured to perform low-pass filtering on the local oscillator dechirped signal to obtain a local oscillator intermediate frequency signal. The first signal processing apparatus includes: a first dechirping device configured to extract a first group of signal components from the echo signal and dechirp the first group of signal components from the echo signal using the current FMCW signal to obtain a first dechirped signal; a first down-conversion device configured to down-convert the first dechirped signal using each signal component of the first signal to obtain a first group of down-converted signals; and a first filtering device configured to perform low-pass filtering on the first group of down-converted signals to obtain a first group of intermediate frequency signals. The second signal processing device includes: a second dechirping device configured to extract a second set of signal components from the echo signal and dechirp the second set of signal components in the echo signal using the current FMCW signal to obtain a second dechirped signal; a second down-conversion device configured to down-convert the second dechirped signal using each signal component in the first signal to obtain a second set of down-converted signals; and a second filtering device configured to low-pass filter the second set of down-converted signals to obtain a second set of intermediate frequency (IF) signals. With this configuration, the local oscillator signal component, the first set of signal components, and the second set of signal components in the echo signal can be processed separately, thereby determining multiple IF signals that respectively indicate the frequency difference between the current FMCW signal and each frequency component in the echo signal for use in ranging and / or speed measurement. Compared to conventional solutions, the electronic circuitry according to this implementation can increase the sweep bandwidth without increasing the sweep period using only one transmit RF channel and one receive RF channel, thereby reducing hardware costs.

[0019] According to a second aspect of this disclosure, an electronic device is provided, comprising: electronic circuitry according to a first aspect of this disclosure, and a power supply configured to supply power to the electronic circuitry. This configuration allows the entire sweep bandwidth of an FMCW radar system to be divided into multiple parallel smaller bandwidths by means of a spread spectrum signal comprising multiple parallel FMCW signal components. This enables the electronic circuitry according to this disclosure to not only achieve both high sweep bandwidth and low sweep period, but also to reduce the number of required transmit and receive radio frequency channels, thereby lowering hardware costs.

[0020] It should be understood that the description in the Summary Section is not intended to limit the key or essential features of this disclosure, nor is it intended to restrict the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0021] The above and other objects, features, and advantages of embodiments of the present disclosure will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of the present disclosure are illustrated in the drawings by way of example and not limitation.

[0022] Figure 1 A schematic diagram of an example environment according to some embodiments of the present disclosure is shown;

[0023] Figure 2 A schematic diagram of the structure of an electronic circuit according to some embodiments of the present disclosure is shown;

[0024] Figure 3 Block diagrams of electronic circuits according to some embodiments of the present disclosure are shown;

[0025] Figure 4 It shows the result of Figure 3 A schematic diagram of the signal components in the spread spectrum signal generated by the electronic circuit shown.

[0026] Figure 5 Block diagrams of electronic circuits according to some embodiments of the present disclosure are shown;

[0027] Figure 6 It shows the result of Figure 5 A schematic diagram of the signal components in the spread spectrum signal generated by the electronic circuit shown.

[0028] Figure 7 Block diagrams of electronic circuits according to some embodiments of the present disclosure are shown;

[0029] Figure 8 It shows the result of Figure 7 A schematic diagram of the signal components in the spread spectrum signal generated by the electronic circuit shown.

[0030] Figure 9 Block diagrams of electronic circuits according to some embodiments of the present disclosure are shown; and

[0031] Figure 10 It shows the result of Figure 9 The diagram shows the signal components in the spread spectrum signal generated by the electronic circuit. Detailed Implementation

[0032] The principles and spirit of this disclosure will be described below with reference to several exemplary embodiments illustrated in the accompanying drawings. It should be understood that these specific embodiments are described merely to enable those skilled in the art to better understand and implement this disclosure, and are not intended to limit the scope of this disclosure in any way. In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art.

[0033] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0034] It should be understood that, in the following description of specific embodiments, some repeated parts of the technical solutions provided in the embodiments of this application may not be repeated, but should be regarded as mutual references between these specific embodiments, and their features can be combined with each other.

[0035] As mentioned above, high-performance FMCW radars require high range resolution and the ability to measure greater velocities. This necessitates a design that balances high sweep bandwidth and low sweep period. A conventional design approach is to equip the FMCW radar system with multiple radar transceivers operating within different sweep bandwidths, thereby increasing the sweep bandwidth while maintaining a constant sweep period. However, this design approach leads to a corresponding increase in the number of radar transceivers in the FMCW radar system, thus increasing hardware costs.

[0036] Embodiments of this disclosure provide an electronic circuit to address one or more of the aforementioned problems and other potential problems. In this disclosure, a signal having at least a fundamental frequency signal component is mixed with an FMCW signal to obtain a swept-frequency signal with multiple parallel FMCW signal components, thereby dividing the entire swept-frequency bandwidth of the FMCW radar system into multiple parallel small bandwidths. In this way, the electronic circuit according to this disclosure not only achieves both high swept-frequency bandwidth and low swept-frequency period, but also reduces the number of required transmit and receive radio frequency channels, thereby reducing hardware costs.

[0037] Figure 1 A schematic diagram of an example environment 100 according to some embodiments of the present disclosure is shown. For example... Figure 1The example environment generally includes a radar system 110 and a target object 120. The radar system 110 may include a digital signal processor (DSP) 112, an analog-to-digital converter (ADC) 114, an FMCW radar 116, and a power supply 118. The FMCW radar 116 transmits an FMCW signal via a transmitter. The transmitted FMCW signal propagates in space and is received by the FMCW radar 116 after being reflected by the target object 120. The FMCW radar 116 signal is processed to determine and output an intermediate frequency (IF) signal, the frequency of which indicates the frequency difference between the received echo signal and the current FMCW signal. After sampling and processing the IF signal using the ADC 114 and DSP 112, the radar system 110 can determine the distance and velocity of the target object 120 relative to the radar system 110. Power supply 118 supplies power to DSP 112, ADC 114, and FMCW radar 116. It should be understood that... Figure 1 The environment 100 shown is merely exemplary, and the solutions according to embodiments of this disclosure can also be applied to other suitable environments. The scope of this disclosure is not limited in this respect.

[0038] Figure 2 A schematic diagram of an electronic circuit 200 according to some embodiments of the present disclosure is shown. This electronic circuit 200 can, for example, serve as… Figure 1 This is a specific implementation of the FMCW radar 116 described herein. For example... Figure 2 As shown, the electronic circuit 200 may include an FMCW signal generator 210, a spread spectrum device 220, a transmitter 230, a receiver 240, and an echo signal processing device 250.

[0039] The FMCW signal generator 210 is configured to generate and output an FMCW signal having a preset sweep period and sweep bandwidth. In the context of this disclosure, an "FMCW signal" refers to a signal whose frequency varies over time. In some embodiments, the FMCW signal generator 210 may directly generate an FMCW signal. In some embodiments, when the desired frequency of the generated FMCW signal is high, the FMCW signal generator 210 may, for example, include a low-frequency FMCW signal generator operating at a lower frequency, and a frequency multiplier. The low-frequency FMCW signal generated by the low-frequency FMCW signal generator can be multiplied by the frequency multiplier to obtain a higher-frequency FMCW signal. This reduces the hardware cost of the FMCW signal generator 210 used for high-frequency FMCW signals. It should be understood that the FMCW signal generator 210 can also be implemented in any other suitable manner, and the scope of this disclosure is not limited in this respect.

[0040] The spread spectrum device 220 is coupled to the FMCW signal generator 210 and generates a spread spectrum signal based on the FMCW signal. It should be noted that, in the context of this disclosure, "spread spectrum" means expanding the sweep bandwidth of the FMCW signal, i.e., increasing the sweep bandwidth of the FMCW signal. The spread spectrum signal generated by the spread spectrum device 220 includes a first group of signal components and a second group of signal components, the sweep bandwidth and sweep period of which are the same as the input FMCW signal, and the frequency band of the first group of signal components is not lower than the frequency band of the second group of signal components, which will be discussed in conjunction with the following. Figures 3 to 10 Further detailed description.

[0041] Transmitter 230 is coupled to spread spectrum device 220 and configured to transmit spread spectrum signals. In some embodiments, transmitter 230 may continuously transmit the spread spectrum signal generated by spread spectrum device 220 for target localization and relative velocity measurement. In some embodiments, transmitter 230 may be implemented as a transmitting antenna. In some embodiments, transmitter 230 may modulate the spread spectrum signal onto an optical carrier and utilize an optical transmitter to transmit the modulated optical signal. It should be understood that transmitter 230 may also be implemented as any other means suitable for transmitting signals, and the scope of this disclosure is not limited in this respect.

[0042] Receiver 240 is configured to receive an echo signal associated with a transmitted spread spectrum signal, such as a signal reflected by target object 120. The echo signal also includes a first set of signal components and a second set of signal components. In some embodiments, receiver 240 may be implemented as one or more receiving antennas. In some embodiments, receiver 240 may be implemented as an optical receiver and receive reflected optical signals. Receiver 240 may also demodulate the received optical signal and use the demodulated signal as an echo signal. It should be understood that receiver 240 may also be implemented as any other means suitable for receiving signals, and the scope of this disclosure is not limited in this respect.

[0043] The echo signal processing device 250 is coupled to the receiver 240, the FMCW signal generator 210, and the spread spectrum device 220, and is configured to determine the frequency difference between the current FMCW signal of the FMCW signal generator 210 and the first and second signal components of the echo signal, respectively, and output a set of intermediate frequency signals associated with the frequency differences, which will be discussed in conjunction with the following. Figures 3 to 10 Further detailed description. It should be noted that, in the context of this disclosure, "current FMCW signal" refers to the FMCW signal used when the echo signal processing device 250 processes the echo signal.

[0044] It should be pointed out that, Figure 2 The schematic diagram shown is merely illustrative. The electronic circuit 200 may also include any other suitable components. For example, an amplifier (not shown) may be provided between the spread spectrum device 220 and the transmitter 230 to amplify the spread spectrum signal, and a low-noise amplifier (not shown) may be provided between the receiver 240 and the echo signal processing device 250 to amplify the echo signal. The scope of this disclosure is not limited in this respect.

[0045] Figure 3 A block diagram of an electronic circuit 300 according to some embodiments of the present disclosure is shown, and Figure 4 It shows the result of Figure 3 This diagram illustrates the signal components in the spread spectrum signal generated by the electronic circuit 300. The electronic circuit 300 can, for example, serve as... Figure 2 An example implementation of the electronic circuit 200 shown. The electronic circuit 300 may include an FMCW signal generator 210, a spread spectrum device 320, a transmitter 230, a receiver 240, and an echo signal processing device 350.

[0046] Since the frequency of the FMCW signal changes periodically with time within the sweep bandwidth, for ease of explanation, in the following discussion, it is assumed that the frequency of the FMCW signal generated by the FMCW signal generator 210 is f0 at time t=T0. Figure 3 The mid-spectrum F302 shows the spectrum of the FMCW signal at time t=T0. It can be seen that the FMCW signal at time t=T0 only has a signal component with frequency f0.

[0047] The spread spectrum device 320 includes an up-converter 324 and a first signal generator 322. The first signal generator 322 is configured to generate a first signal that includes a fundamental frequency signal component. Figure 3 The spectrum F304 in the diagram shows that the first signal has a fundamental signal component with a frequency of f1. It should be understood that the first signal may also include harmonic signal components, and the scope of this disclosure is not limited in this respect. In some embodiments, the first signal generator 322 may include an oscillator to generate the fundamental signal. The first signal generator 322 may also include a frequency multiplier, mixer, or divider to generate harmonic signals based on the fundamental signal, and a signal synthesizer to combine the fundamental signal and harmonic signals into a single signal as the first signal. In some embodiments, the first signal generator 322 may be implemented digitally, i.e., using a DSP to directly generate the desired signal, and converting it to an analog signal via a digital-to-analog converter (DAC) as the first signal. It should be understood that the first signal generator 322 may also be implemented in any other suitable manner, and the scope of this disclosure is not limited in this respect.

[0048] The upconversion device 324 is coupled to the FMCW signal generator 210 and configured to upconvert the first signal using the FMCW signal to generate a spread spectrum signal. Figure 3 In the illustrated embodiment, a double-balanced mixer is used to implement the upconversion device 324. In other words, the signal output by the upconversion device 324 consists of the two sidebands of the mixer signal, excluding the local oscillator signal (i.e., the input FMCW signal) and the first signal. In this case, the spread spectrum signal output by the upconversion device 324 consists of a first group of signal components and a second group of signal components. The frequency of the first group of signal components is greater than the frequency of the FMCW signal and includes the sum of the frequency of the FMCW signal and the frequency of the fundamental signal component (see [link to documentation]). Figure 3 The signal component with frequency f0+f1 in spectrum F306), while the frequency of the second group of signal components is lower than the frequency of the FMCW signal, and includes the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component (see [reference]). Figure 3 (The signal components with frequencies f0-f1 in spectrum F306).

[0049] like Figure 4As shown, since the local oscillator signal is suppressed, the spread spectrum signal does not include a signal component corresponding to frequency f0. The first group of signal components includes a signal component S410 corresponding to frequency f0+f1, and the second group of signal components includes a signal component S420 corresponding to frequency f0-f1. In some embodiments, when the first signal includes, for example, a harmonic signal component with frequency 2f1, the first group of signal components also includes a signal component with a higher frequency than signal component S410, i.e., a frequency signal component corresponding to frequency f0+2f1, and the second group of signal components also includes a signal component with a lower frequency than signal component S420, i.e., a frequency signal component corresponding to frequency f0-2f1. It should be understood that, in Figure 4 The example shown is an FMCW signal with a sawtooth wave, illustrating the various signal components of a spread spectrum signal. However, an FMCW signal can also have any other suitable waveform, such as a triangular wave. The scope of this disclosure is not limited in this respect.

[0050] exist Figure 4 As can be seen, each signal component in the spread spectrum signal has a sweep bandwidth B and a sweep period T. C Furthermore, the frequency interval Δf between two adjacent signal components S410 and S420 is equal to 2. f1. To ensure the normal operation of radar system 110, frequency overlap between two adjacent signal components must be avoided. In other words, the frequency interval Δf should not be less than the sweep bandwidth B, i.e., Δf = 2. f1 ≥ B. Therefore, the frequency of the fundamental signal component in the first signal generated by the first signal generator 322 should be greater than or equal to half the sweep bandwidth of the FMCW signal. In addition, when the first signal also includes harmonic signal components, in order to avoid frequency overlap between two adjacent signal components, it is necessary to ensure that the frequency difference between two adjacent signal components in the first signal is not less than the sweep bandwidth B.

[0051] By utilizing the configuration of the spread spectrum device 320 described above, the electronic circuit 300 according to embodiments of the present disclosure can mix the first signal with the FMCW signal to obtain a swept frequency signal with multiple parallel FMCW signal components, thereby dividing the entire swept frequency bandwidth of the FMCW radar system into multiple parallel small bandwidths. In this way, the electronic circuit 300 according to the present disclosure can balance high swept frequency bandwidth and low swept frequency period, thereby supporting the measurement of higher speeds and providing higher range resolution.

[0052] Return to Reference Figure 3 Because the received echo signal contains a first set of signal components and a second set of signal components whose frequencies are symmetrical about the frequency f0 of the FMCW signal (see...). Figure 3The signal components in the spectrum F308 have frequencies of f0+f1 and f0-f1. Therefore, if the echo signal is dechirped using the current FMCW signal according to conventional processing methods, the frequencies of the two sets of dechirped signals corresponding to the first and second sets of signal components will be the same, making it difficult to distinguish between the two sets of dechirped signals. Therefore, in the receiving channel of the electronic circuit 300 according to this disclosure, it is necessary to process the first and second sets of signal components in the echo signal separately.

[0053] like Figure 3 As shown, the echo signal processing device 350 may include a first signal processing device 352 and a second signal processing device 354. The first signal processing device 352 is used to process a first set of signal components in the echo signal, and the second signal processing device 354 is used to process a second set of signal components in the echo signal. The first signal processing device 352 may include a first dechirping device 3522, a first down-conversion device 3524, and a first filtering device 3526.

[0054] A first dechirping device 3522 is coupled to the receiver 240 and the FMCW signal generator 210. The first dechirping device 3522 is configured to extract a first set of signal components from the echo signal and dechirp the first set of signal components in the echo signal using the current FMCW signal to obtain a first dechirped signal. In some embodiments, the first dechirping device 3522 may include a high-pass filter and a down-converter. Using the high-pass filter, the first dechirping device 3522 can filter out a second set of signal components with relatively lower frequencies from the echo signal to extract the first set of signal components with relatively higher frequencies. The filtered first set of signal components can be input to the down-converter along with the current FMCW signal generated by the FMCW signal generator 210 to dechirp the first set of signal components and obtain the first dechirped signal. In some embodiments, a band-pass filter can also be used to filter out the second set of signal components and extract the first set of signal components. In some embodiments, the downconverter may also be configured to suppress the first set of signal components, thereby eliminating the need for a filter. It should be understood that the first dechirping device 3522 may also be implemented with any other suitable components or means, and the scope of this disclosure is not limited in this respect.

[0055] The first dechirped signal consists of the superposition of the corresponding intermediate frequency signal component obtained after dechirping and the signal component in the first signal (see [link]). Figure 3 In the spectrum F310, the frequency is f1+f IF1 (The signal components). Therefore, the corresponding intermediate frequency signal components can be extracted by means of the first downconverter 3524 and the first filter 3526 connected downstream of the first dechirping device 3522.

[0056] A first downconverter 3524 is coupled to a first signal generator 322 and a first dechirping device 3522, and is configured to downconvert the first dechirped signal using each signal component of the first signal to obtain a first set of downconverted signals. In some embodiments, a set of downconverters is provided in the first downconverter 3524 according to the number of signal components in the first set of signal components in the spread spectrum signal, and one input terminal of each downconverter in the set of downconverters is input with the first dechirped signal, while the other input terminal is input with a signal corresponding to a corresponding signal component in the first signal, such as a signal corresponding to a fundamental signal component or a signal corresponding to a specific harmonic signal component, etc. The obtained first set of downconverted signals can be low-pass filtered by a first filter 3526 to obtain a first set of intermediate frequency (IF) signals. The frequency of each IF signal in the first set of IF signals indicates the frequency difference between the current FMCW signal and the corresponding signal component in the first set of signal components in the echo signal. For example, Figure 3 The spectrum F312 in the image shows a frequency f IF1 The intermediate frequency signal. The frequency of the intermediate frequency signal indicates the frequency difference between the current FMCW signal and the signal component with frequency f0+f1 in the first group of signal components. It should be understood that the first downconverter 3524 and the first filter 3526 can also be implemented with any other suitable components or devices, and the scope of this disclosure is not limited in this respect.

[0057] Similar to the first signal processing device 352, the second signal processing device 354 may include a second dechirping device 3542, a second down-conversion device 3544, and a second filtering device 3546. The second signal processing device 354 is configured to extract a second set of signal components from the echo signal and generate a second set of intermediate frequency (IF) signals based on the second set of signal components in the echo signal, the current FMCW signal, and the first signal. The frequency of each IF signal in the second set of IF signals indicates the frequency difference between the current FMCW signal and the corresponding signal component in the second set of signal components in the echo signal.

[0058] A second dechirping device 3542 is coupled to the receiver 240 and the FMCW signal generator 210, and is configured to extract a second set of signal components from the echo signal, and to dechirp the second set of signal components in the echo signal using the current FMCW signal to obtain a second dechirped signal. In some embodiments, the second dechirping device 3542 may include a low-pass filter and a downconverter. Using the low-pass filter, the second dechirping device 3542 can filter out a first set of signal components with relatively high frequencies from the echo signal to extract a second set of signal components with relatively low frequencies. The filtered second set of signal components can be input to the downconverter along with the current FMCW signal generated by the FMCW signal generator 210 to dechirp the second set of signal components and obtain the second dechirped signal. In some embodiments, a band-pass filter can also be used to filter out the first set of signal components and extract the second set of signal components. In some embodiments, the downconverter can also be configured to suppress the first set of signal components, thereby eliminating the need for a filter. It should be understood that the second dechirping device 3542 can also be implemented with any other suitable components or devices, and the scope of this disclosure is not limited in this respect.

[0059] Similar to the first dechirped signal, the second dechirped signal comprises the superposition of the corresponding intermediate frequency (IF) signal component obtained after dechirping and the signal component in the first signal. Therefore, the corresponding IF signal component can be extracted by means of a second downconverter 3544 and a second filter 3546 connected downstream of the second dechirped device 3542. The second downconverter 3544 and the second filter 3546 can be configured in a similar manner to the first downconverter 3524 and the first filter 3526, and therefore will not be described further herein.

[0060] The first and second intermediate frequency (IF) signals output by the echo signal processing device 350 can be sampled by the ADC 114 and then input into the DSP 112 for processing. For speed measurement applications, either the first or second IF signal can be used. In other words, a sub-sweep bandwidth B of the total sweep bandwidth of the spread spectrum signal is used to determine the speed. For ranging applications, the first and second IF signals can be spliced ​​in the DSP 112 to obtain an IF signal corresponding to the total sweep bandwidth of the spread spectrum signal. In other words, the entire sweep bandwidth of the spread spectrum signal can be used to determine the distance, thereby improving the distance resolution. In this way, the electronic circuit 300 according to the embodiments of this disclosure can increase the sweep bandwidth without increasing the sweep period, thus achieving both high sweep bandwidth and low sweep period. Furthermore, compared to conventional solutions, the electronic circuit 300 according to the embodiments of this disclosure can operate using only one transmit RF channel and one receive RF channel, thus reducing hardware costs.

[0061] Figure 5 A block diagram of an electronic circuit 500 according to some embodiments of the present disclosure is shown, and Figure 6 It shows the result of Figure 5 This diagram illustrates the signal components in the spread spectrum signal generated by the electronic circuit 500. The electronic circuit 500 can, for example, serve as... Figure 2 An example implementation of the electronic circuit 200 shown. The electronic circuit 500 may include an FMCW signal generator 210, a spread spectrum device 520, a transmitter 230, a receiver 240, and an echo signal processing device 550.

[0062] The spread spectrum device 520 includes an upconverter 524 and a first signal generator 522. The first signal generator 522 is configured to generate a first signal that includes a fundamental signal component and harmonic signal components. Figure 5 The spectrum F504 in the diagram shows that the first signal has a fundamental signal component with frequency f1 and a harmonic signal component with frequency 2f1. It should be understood that the first signal may also include other harmonic signal components, and the scope of this disclosure is not limited in this respect. The first signal generator 522 can be used with... Figure 3 The first signal generator 322 in the above is implemented in a similar manner, which will not be described in detail here.

[0063] The upconversion device 524 is coupled to the FMCW signal generator 210 and configured to upconvert the first signal using the FMCW signal to generate a spread spectrum signal. Figure 5In the illustrated embodiment, a single-sideband mixer is used to implement the upconversion device 524. In other words, the signal output by the upconversion device 524 consists of one sideband of the mixer signal, and does not include the local oscillator signal (i.e., the input FMCW signal) and the first signal.

[0064] In some embodiments, the upconversion device 524 can be implemented using an upper sideband mixer. In other words, the signal output by the upconversion device 524 consists of the upper sideband of the mixer signal. In this case, the spread spectrum signal output by the upconversion device 524 consists of a first group of signal components and a second group of signal components. The frequency of the first group of signal components is greater than the frequency of the FMCW signal, and includes the sum of the frequencies of the harmonic signals and the FMCW signal (see [link to documentation]). Figure 5 In the spectrum F506, the signal component with frequency f0+2f1), the frequency of the second group of signal components is greater than the frequency of the FMCW signal, and includes the sum of the frequency of the fundamental signal component and the frequency of the FMCW signal (see...). Figure 5 (The signal component with frequency f0+f1 in spectrum F506).

[0065] In some embodiments, the upconversion device 524 can be implemented using a lower sideband mixer. In other words, the signal output by the upconversion device 524 consists of the lower sideband of the mixed signal. In this case, similar to the case of an upper sideband mixer, the spread spectrum signal consists of a first group of signal components and a second group of signal components. The frequency of the first group of signal components is lower than the frequency of the FMCW signal and includes the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component. The frequency of the second group of signal components is lower than the frequency of the FMCW signal and includes the difference between the frequency of the FMCW signal and the frequency of the harmonic signal.

[0066] Since the operation of the upper sideband mixer is similar to that of the lower sideband mixer, and the hardware design of the remaining components in the electronic circuit 500 is basically the same in both cases, for the sake of simplicity, the following description will take the upconverter 524 implemented using the upper sideband mixer as an example.

[0067] like Figure 6 As shown, since the lower sideband and local oscillator signal in the mixing signal are suppressed, signal components corresponding to frequencies f0, f0-f1, and f0-2f1 are not included in the spread spectrum signal. The first group of signal components includes a frequency signal component S610 corresponding to frequency f0+2f1, and the second group of signal components includes a signal component S620 corresponding to frequency f0+f1. In some embodiments, when the first signal includes, for example, a harmonic signal component with a frequency of 3f1, the first group of signal components may also include a signal component with a higher frequency than signal component S610, i.e., a frequency signal component corresponding to frequency f0+3f1. It should be understood that, in Figure 6The example shown is an FMCW signal with a sawtooth wave, illustrating the various signal components of a spread spectrum signal. However, an FMCW signal can also have any other suitable waveform, such as a triangular wave. The scope of this disclosure is not limited in this respect.

[0068] exist Figure 6 As can be seen, each signal component in the spread spectrum signal has a sweep bandwidth B and a sweep period T. C Furthermore, the frequency interval Δf between two adjacent signal components S610 and S620 is equal to f1. To ensure the normal operation of the radar system 110, it is necessary to avoid frequency overlap between two adjacent signal components. In other words, the frequency interval Δf should not be less than the sweep bandwidth B, i.e., Δf = f1 ≥ B. Therefore, the frequency of the fundamental signal component in the first signal generated by the first signal generator 522 should be greater than or equal to the sweep bandwidth of the FMCW signal. In addition, when the first signal also includes other harmonic signal components, in order to avoid frequency overlap between two adjacent signal components, it is necessary to ensure that the frequency difference between two adjacent signal components in the first signal is not less than the sweep bandwidth B.

[0069] By utilizing the configuration of the spread spectrum device 520 described above, the electronic circuit 500 according to embodiments of the present disclosure can mix the first signal with the FMCW signal to obtain a swept frequency signal with multiple parallel FMCW signal components, thereby dividing the entire swept frequency bandwidth of the FMCW radar system into multiple parallel small bandwidths. In this way, the electronic circuit 500 according to the present disclosure can balance high swept frequency bandwidth and low swept frequency period, thereby supporting the measurement of higher speeds and providing higher range resolution.

[0070] Return to Reference Figure 5 Since the received echo signal only includes the upper sideband of the mixer signal, that is, the signal components with frequencies greater than frequency f0. In other words, the frequencies of the first and second groups of signal components in the echo signal are both greater than frequency f0 (see...). Figure 5 (The signal components with frequencies f0+f1 and f0+2f1 in the spectrum F508). Therefore, in Figure 5 In the illustrated embodiment, it is not necessary to... Figure 3 The first and second groups of signal components in the echo signal are processed separately as described in the previous method. It should be understood that the first and second groups of signal components can also be processed separately as needed. The scope of this disclosure is not limited in this respect.

[0071] like Figure 5As shown, the echo signal processing apparatus 550 may include a dechirping device 552, a down-conversion device 554, and a filtering device 556. The dechirping device 552 is coupled to the receiver 240 and the FMCW signal generator 210 and is configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal. In some embodiments, the dechirping device 552 may include a down-converter. The echo signal may be input to the down-converter along with the current FMCW signal generated by the FMCW signal generator 210 to dechirp the echo signal and obtain a dechirped signal. The dechirped signal includes the superposition of the corresponding intermediate frequency signal component obtained after dechirping and the signal component in the first signal (see [link to relevant documentation]). Figure 5 The frequency in spectrum F510 is f1+f IF1 and 2f1+f IF2 (The signal components). Therefore, the corresponding intermediate frequency signal components can be extracted by means of the downconverter 554 and filter 556 connected downstream of the dechirping device 552.

[0072] The downconverter 554 is coupled to the dechirping device 552 and the first signal generator 522, and is configured to downconvert the dechirped signal using each signal component of the first signal to obtain a set of downconverted signals. In some embodiments, a set of downconverters is provided in the downconverter 554 according to the number of signal components in the spread spectrum signal, and one input of each downconverter in the set is input with the dechirped signal, while the other input is input with a signal corresponding to a corresponding signal component in the first signal, such as a signal corresponding to a fundamental signal component or a signal corresponding to a specific harmonic signal component, etc. The obtained downconverted signal is low-pass filtered by the filter 556 to obtain a set of intermediate frequency (IF) signals. The frequency of each IF signal in this set indicates the frequency difference between the current FMCW signal and the corresponding signal component in the echo signal. For example, Figure 5 The spectrum F512 in the image shows a frequency f IF1 The first intermediate frequency signal and having a frequency f IF2 The second intermediate frequency signal. The frequency of the first intermediate frequency signal indicates the frequency difference between the current FMCW signal and the signal component with frequency f0+f1 in the echo signal, while the frequency of the second intermediate frequency signal indicates the frequency difference between the current FMCW signal and the signal component with frequency f0+2f1 in the echo signal.

[0073] The intermediate frequency (IF) signals output by the filter 556 can be sampled by the ADC 114 and then processed by the DSP 112. For speed measurement applications, any one of the IF signals in this group can be used. In other words, a sub-sweep bandwidth B of the total sweep bandwidth of the spread spectrum signal is used to determine the speed. For ranging applications, the IF signals in this group can be spliced ​​in the DSP 112 to obtain an IF signal corresponding to the total sweep bandwidth of the spread spectrum signal. In other words, the entire sweep bandwidth of the spread spectrum signal can be used to determine the distance, thereby improving the distance resolution. In this way, the electronic circuit 500 according to the embodiments of this disclosure can increase the sweep bandwidth without increasing the sweep period, thus achieving both high sweep bandwidth and low sweep period. Furthermore, compared to conventional solutions, the electronic circuit 500 according to the embodiments of this disclosure can operate using only one transmit RF channel and one receive RF channel, thus reducing hardware costs.

[0074] Figure 7 A block diagram of an electronic circuit 700 according to some embodiments of the present disclosure is shown, and Figure 8 It shows the result of Figure 7 This diagram illustrates the signal components in the spread spectrum signal generated by the electronic circuit 700. The electronic circuit 700 can, for example, serve as... Figure 2 An example implementation of the electronic circuit 200 shown. The electronic circuit 700 may include an FMCW signal generator 210, a spread spectrum device 720, a transmitter 230, a receiver 240, and an echo signal processing device 750.

[0075] The spread spectrum device 720 includes an upconverter 724 and a first signal generator 722. The first signal generator 722 is configured to generate a first signal that includes a fundamental frequency signal component. Figure 7 The spectrum F704 in the diagram shows that the first signal has a fundamental signal component with a frequency of f1. It should be understood that the first signal may also include harmonic signal components, and the scope of this disclosure is not limited in this respect. The first signal generator 722 can be used with... Figure 3 The first signal generator 322 in the above is implemented in a similar manner, which will not be described in detail here.

[0076] The upconversion device 724 is coupled to the FMCW signal generator 210 and configured to upconvert the first signal using the FMCW signal to generate a spread spectrum signal. Figure 7 In the illustrated embodiment, the upconversion device 724 is implemented using a single-sideband unbalanced mixer. In other words, the signal output by the upconversion device 724 consists of one sideband of the mixer signal and the local oscillator signal (i.e., the input FMCW signal).

[0077] In some embodiments, the upconversion device 724 can be implemented using an upper sideband unbalanced mixer. In other words, the signal output by the upconversion device 724 consists of the upper sideband of the mixer signal and the local oscillator signal. In this case, the spread spectrum signal output by the upconversion device 724 consists of a first group of signal components and a second group of signal components. The frequency of the first group of signal components is greater than the frequency of the FMCW signal and includes the sum of the frequency of the FMCW signal and the frequency of the fundamental signal component (see...). Figure 7 The signal component with frequency f0+f1 in spectrum F706), the frequency of the second group of signal components is the frequency of the FMCW signal (see...). Figure 7 (The signal component with frequency f0 in spectrum F706).

[0078] In some embodiments, the upconversion device 724 can be implemented using a lower sideband unbalanced mixer. In other words, the signal output by the upconversion device 724 consists of the lower sideband of the mixer signal and the local oscillator signal. In this case, the spread spectrum signal output by the upconversion device 724 consists of a first group of signal components and a second group of signal components. The frequency of the first group of signal components is the frequency of the FMCW signal, and the frequency of the second group of signal components is lower than the frequency of the FMCW signal, and includes the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component.

[0079] Since the operation of the upper sideband unbalanced mixer is similar to that of the lower sideband unbalanced mixer, and the hardware design of the remaining components in the electronic circuit 700 is basically the same in both cases, for the sake of simplicity, the following description will take the upconverter 724 implemented using the upper sideband unbalanced mixer as an example.

[0080] like Figure 8 As shown, since the lower sideband in the mixing signal is suppressed, the spread spectrum signal does not include signal components corresponding to frequencies f0-f1. The first group of signal components includes a frequency signal component S810 corresponding to frequency f0+f1, and the second group of signal components includes a signal component S820 corresponding to frequency f0. In some embodiments, when the first signal includes, for example, a harmonic signal component with a frequency of 2f1, the first group of signal components may also include signal components with a higher frequency than signal component S810, i.e., frequency signal components corresponding to frequency f0+2f1. It should be understood that, in Figure 8 The example shown is an FMCW signal with a sawtooth wave, illustrating the various signal components of a spread spectrum signal. However, an FMCW signal can also have any other suitable waveform, such as a triangular wave. The scope of this disclosure is not limited in this respect.

[0081] exist Figure 8 As can be seen, each signal component in the spread spectrum signal has a sweep bandwidth B and a sweep period T. CFurthermore, the frequency interval Δf between two adjacent signal components S810 and S820 is equal to f1. To ensure the normal operation of the radar system 110, it is necessary to avoid frequency overlap between two adjacent signal components. In other words, the frequency interval Δf should not be less than the sweep bandwidth B, i.e., Δf = f1 ≥ B. Therefore, the frequency of the fundamental signal component in the first signal generated by the first signal generator 722 should be greater than or equal to the sweep bandwidth of the FMCW signal. In addition, when the first signal also includes harmonic signal components, in order to avoid frequency overlap between two adjacent signal components, it is necessary to ensure that the frequency difference between two adjacent signal components in the first signal is not less than the sweep bandwidth B.

[0082] By utilizing the configuration of the spread spectrum device 720 described above, the electronic circuit 700 according to embodiments of the present disclosure can mix the first signal with the FMCW signal to obtain a swept frequency signal with multiple parallel FMCW signal components, thereby dividing the entire swept frequency bandwidth of the FMCW radar system into multiple parallel small bandwidths. In this way, the electronic circuit 700 according to the present disclosure can balance high swept frequency bandwidth and low swept frequency period, thereby supporting the measurement of higher speeds and providing higher range resolution.

[0083] Return to Reference Figure 7 The received echo signal consists of the upper sideband of the mixer signal and the local oscillator signal. In other words, the frequencies of the first and second signal components in the echo signal are both greater than or equal to frequency f0 (see...). Figure 7 (The signal components with frequencies f0 and f0+f1 in the spectrum F708). Therefore, in Figure 7 In the illustrated embodiment, it is not necessary to... Figure 3 The first and second groups of signal components in the echo signal are processed separately as described in the previous method. It should be understood that the first and second groups of signal components can also be processed separately as needed. The scope of this disclosure is not limited in this respect.

[0084] like Figure 7 As shown, the echo signal processing apparatus 750 may include a dechirping device 752, a down-conversion device 754, a first filter device 756, and a second filter device 758. The dechirping device 752 is coupled to the receiver 240 and the FMCW signal generator 210 and is configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal. In some embodiments, the dechirping device 752 may include a down-converter. The echo signal may be input to the down-converter along with the current FMCW signal generated by the FMCW signal generator 210 to dechirp the echo signal and obtain a dechirped signal. The dechirped signal includes: a dechirped intermediate frequency signal component corresponding to the local oscillator signal (see [link to relevant documentation]). Figure 7The frequency in spectrum F710 is f IF1 The signal components), and the superposition of the dechirped intermediate frequency signal component corresponding to the upper sideband of the mixer signal with the signal components in the first signal (see [reference]). Figure 7 The frequency in spectrum F710 is f1+f IF2 (signal components).

[0085] For the chirped intermediate frequency (IF) component corresponding to the local oscillator signal, since the frequency f1 of the fundamental signal component is usually much higher than the frequency f of the IF signal... IF1 Therefore, the chirped signal can be directly low-pass filtered using the second filter device 758 to obtain the local oscillator intermediate frequency (LOIF) signal. The frequency of this LOIF signal indicates the frequency difference between the current FMCW signal and the LOIF component in the echo signal. For example, Figure 7 The spectrum F714 in the image shows a frequency f IF1 The local oscillator intermediate frequency signal, the frequency of which indicates the frequency difference between the current FMCW signal and the signal component with frequency f0 in the echo signal.

[0086] For the superposition of intermediate frequency (IF) signal components with signal components in the first signal, the corresponding IF signal components are extracted by means of a downconverter connected downstream of the dechirping device 752 and a first filter device 756. The downconverter is coupled to the dechirping device 752 and the first signal generator 722, and is configured to downconvert the dechirped signal using each signal component in the first signal to obtain a set of downconverted signals. In some embodiments, a set of downconverters is provided in the downconverter according to the number of signal components in the spread spectrum signal, and one input terminal of each downconverter in the set is input with the dechirped signal, while the other input terminal is input with a signal corresponding to the corresponding signal component in the first signal, such as a signal corresponding to the fundamental signal component or a signal corresponding to a specific harmonic signal component, etc. The obtained downconverted signal is low-pass filtered by the first filter device 756 to obtain a set of IF signals. The frequency of each intermediate frequency (IF) signal in this set indicates the frequency difference between the current FMCW signal and the corresponding signal component in the echo signal. For example, Figure 7 The spectrum F712 in the image shows a frequency f IF2 The intermediate frequency signal, whose frequency indicates the frequency difference between the current FMCW signal and the signal component with frequency f0+f1 in the echo signal.

[0087] The intermediate frequency (IF) signals output by the first filter 756 and the local oscillator (LO) IF signals output by the second filter 758 can be sampled by the ADC 114 and then input together into the DSP 112 for processing. For speed measurement applications, any one of the multiple IF signals can be used. In other words, a sub-sweep bandwidth B of the total sweep bandwidth of the spread spectrum signal is used to determine the speed. For ranging applications, all the multiple IF signals can be spliced ​​in the DSP 112 to obtain an IF signal corresponding to the total sweep bandwidth of the spread spectrum signal. In other words, the entire sweep bandwidth of the spread spectrum signal can be used to determine the distance, thereby improving the distance resolution. In this way, the electronic circuit 700 according to the embodiments of this disclosure can increase the sweep bandwidth without increasing the sweep period, thus achieving both high sweep bandwidth and low sweep period. Furthermore, compared to conventional solutions, the electronic circuit 700 according to the embodiments of this disclosure can operate using only one transmit RF channel and one receive RF channel, thus reducing hardware costs.

[0088] Figure 9 A block diagram of an electronic circuit 900 according to some embodiments of the present disclosure is shown, and Figure 10 It shows the result of Figure 9 This diagram illustrates the signal components in the spread spectrum signal generated by the electronic circuit 900. The electronic circuit 900 can, for example, serve as... Figure 2 An example implementation of the electronic circuit 200 shown is described. The electronic circuit 900 may include an FMCW signal generator 210, a spread spectrum device 920, a transmitter 230, a receiver 240, and an echo signal processing device 950.

[0089] The spread spectrum device 920 includes an upconverter 924 and a first signal generator 922. The first signal generator 922 is configured to generate a first signal that includes a fundamental frequency signal component. Figure 9 The spectrum F904 in the diagram shows that the first signal has a fundamental signal component with a frequency of f1. It should be understood that the first signal may also include harmonic signal components, and the scope of this disclosure is not limited in this respect. The first signal generator 922 can be used with... Figure 3 The first signal generator 322 in the above is implemented in a similar manner, which will not be described in detail here.

[0090] The upconversion device 924 is coupled to the FMCW signal generator 210 and configured to upconvert the first signal using the FMCW signal to generate a spread spectrum signal. Figure 9In the illustrated embodiment, the upconversion device 924 is implemented using a double-sideband unbalanced mixer. In other words, the signal output by the upconversion device 924 consists of the two sidebands of the mixer signal and the local oscillator signal (i.e., the input FMCW signal). In this case, the spread spectrum signal output by the upconversion device 924 consists of a local oscillator signal component, a first group of signal components, and a second group of signal components. The frequency of the local oscillator signal component is the frequency of the FMCW signal (see [link to documentation]). Figure 9 The signal component with frequency f0 in spectrum F906), the frequency of the first group of signal components is greater than the frequency of the FMCW signal, and includes the sum of the frequency of the FMCW signal and the frequency of the fundamental signal component (see [link]). Figure 3 The signal component with frequency f0+f1 in spectrum F306), the second group of signal components has a frequency lower than the frequency of the FMCW signal, and includes the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component (see [reference]). Figure 9 (The signal components with frequencies f0-f1 in spectrum F906).

[0091] like Figure 10 As shown, the local oscillator signal component is the signal component S1020 corresponding to frequency f0, the first group of signal components includes the frequency signal component S1010 corresponding to frequency f0+f1, and the second group of signal components includes the signal component S1030 corresponding to frequency f0-f1. In some embodiments, when the first signal includes, for example, a harmonic signal component with frequency 2f1, the first group of signal components may further include a signal component with a higher frequency than signal component S1010, i.e., a frequency signal component corresponding to frequency f0+2f1, and the second group of signal components may further include a signal component with a lower frequency than signal component S1020, i.e., a frequency signal component corresponding to frequency f0-2f1. It should be understood that, in Figure 10 The example shown is an FMCW signal with a sawtooth wave, illustrating the various signal components of a spread spectrum signal. However, an FMCW signal can also have any other suitable waveform, such as a triangular wave. The scope of this disclosure is not limited in this respect.

[0092] exist Figure 10 As can be seen, each signal component in the spread spectrum signal has a sweep bandwidth B and a sweep period T. CFurthermore, the frequency interval Δf between two adjacent signal components S1010 and S1020, and between S1020 and S1030, is equal to f1. To ensure the normal operation of the radar system 110, it is necessary to avoid frequency overlap between two adjacent signal components. In other words, the frequency interval Δf should not be less than the sweep bandwidth B, i.e., Δf = f1 ≥ B. Therefore, the frequency of the fundamental signal component in the first signal generated by the first signal generator 922 should be greater than or equal to the sweep bandwidth of the FMCW signal. In addition, when the first signal also includes other harmonic signal components, in order to avoid frequency overlap between two adjacent signal components, it is necessary to ensure that the frequency difference between two adjacent signal components in the first signal is not less than the sweep bandwidth B.

[0093] By utilizing the configuration of the spread spectrum device 920 described above, the electronic circuit 900 according to an embodiment of the present disclosure can mix the first signal with the FMCW signal to obtain a swept frequency signal with multiple parallel FMCW signal components, thereby dividing the entire swept frequency bandwidth of the FMCW radar system into multiple parallel small bandwidths. In this way, the electronic circuit 900 according to the present disclosure can balance high swept frequency bandwidth and low swept frequency period, thereby supporting the measurement of higher speeds and providing higher range resolution.

[0094] Return to Reference Figure 9 Because the received echo signal contains a first set of signal components and a second set of signal components whose frequencies are symmetrical about the frequency f0 of the FMCW signal (see...). Figure 9 The signal components in the spectrum F908 have frequencies of f0+f1 and f0-f1. Therefore, if the echo signal is dechirped using the current FMCW signal according to conventional processing methods, the frequencies of the two sets of dechirped signals corresponding to the first and second sets of signal components will be the same, making it difficult to distinguish between the two sets of dechirped signals. Therefore, in the receiving channel of the electronic circuit 900 according to this disclosure, it is necessary to process the first and second sets of signal components in the echo signal separately.

[0095] like Figure 9 As shown, the echo signal processing device 950 may include a first signal processing device 952, a second signal processing device 954, and a local oscillator signal processing device 956. The first signal processing device 952 is used to process a first set of signal components in the echo signal, the second signal processing device 954 is used to process a second set of signal components in the echo signal, and the local oscillator signal processing device 956 is used to process the local oscillator signal component in the echo signal.

[0096] The first signal processing device 952 may include a first dechirping device 9522, a first down-conversion device 9524, and a first filtering device 9526. The first dechirping device 9522 is coupled to the receiver 240 and the FMCW signal generator 210, and is configured to extract a first set of signal components from the echo signal, and to dechirp the first set of signal components in the echo signal using the current FMCW signal to obtain a first dechirped signal. In some embodiments, the first dechirping device 9522 may include a high-pass filter and a down-converter. Using the high-pass filter, the first dechirping device 9522 can filter out a second set of signal components with relatively lower frequencies from the echo signal to extract the first set of signal components with relatively higher frequencies. The filtered first set of signal components can be input to the down-converter along with the current FMCW signal generated by the FMCW signal generator 210 to dechirp the first set of signal components and obtain the first dechirped signal. In some embodiments, a bandpass filter can also be used to filter out the second group of signal components and extract the first group of signal components. In some embodiments, the downconverter can also be configured to suppress the first group of signal components, thereby eliminating the need for a filter. It should be understood that the first dechirping device 9522 can also be implemented with any other suitable components or devices, and the scope of this disclosure is not limited in this respect.

[0097] The first dechirped signal consists of the superposition of the corresponding intermediate frequency signal component obtained after dechirping and the signal component in the first signal (see [link]). Figure 9 In the spectrum F910, the frequency is f1+f IF1 (The signal components). Therefore, the corresponding intermediate frequency signal components can be extracted by means of the first downconverter 9524 and the first filter 9526 connected downstream of the first dechirping device 9522.

[0098] A first downconverter 9524 is coupled to a first signal generator 922 and a first dechirping device 9522, and is configured to downconvert the first dechirped signal using each signal component of the first signal to obtain a first set of downconverted signals. In some embodiments, a set of downconverters is provided in the first downconverter 9524 according to the number of signal components in the first set of signal components in the spread spectrum signal, and one input terminal of each downconverter in the set of downconverters is input with the first dechirped signal, while the other input terminal is input with a signal corresponding to a corresponding signal component in the first signal, such as a signal corresponding to a fundamental signal component or a signal corresponding to a specific harmonic signal component, etc. The obtained first set of downconverted signals can be low-pass filtered by a first filter device 9526 to obtain a first set of intermediate frequency (IF) signals. The frequency of each IF signal in the first set of IF signals indicates the frequency difference between the current FMCW signal and the corresponding signal component in the first set of signal components in the echo signal. For example, Figure 9 The spectrum F912 in the image shows a frequency f IF1 The intermediate frequency signal. The frequency of the intermediate frequency signal indicates the frequency difference between the current FMCW signal and the signal component with frequency f0+f1 in the first group of signal components. It should be understood that the first downconverter 9524 and the first filter 9526 can also be implemented with any other suitable components or devices, and the scope of this disclosure is not limited in this respect.

[0099] The second signal processing device 954 may include a second dechirping device 9542, a second down-conversion device 9544, and a second filtering device 9546. Similar to the first signal processing device 952, the second signal processing device 954 is configured to extract a second set of signal components from the echo signal and generate a second set of intermediate frequency (IF) signals based on the second set of signal components in the echo signal, the current FMCW signal, and the first signal. The frequency of each IF signal in the second set of IF signals indicates the frequency difference between the current FMCW signal and the corresponding signal component in the second set of signal components in the echo signal.

[0100] A second dechirping device 9542 is coupled to receiver 240 and FMCW signal generator 210 and configured to extract a second set of signal components from the echo signal and dechirp the second set of signal components in the echo signal using the current FMCW signal to obtain a second dechirped signal. In some embodiments, the second dechirping device 9542 may include a low-pass filter and a downconverter. Using the low-pass filter, the second dechirping device 9542 can filter out a first set of signal components with relatively high frequencies from the echo signal to extract a second set of signal components with relatively low frequencies. The filtered second set of signal components can be input to the downconverter along with the current FMCW signal generated by FMCW signal generator 210 to dechirp the second set of signal components, obtaining a second dechirped signal. Similar to the first dechirped signal, the second dechirped signal includes the superposition of the corresponding intermediate frequency signal component obtained after dechirping and the signal components in the first signal. In some embodiments, a bandpass filter can also be used to filter out the first group of signal components and extract the second group of signal components. In some embodiments, the downconverter can also be configured to suppress the first group of signal components, thereby eliminating the need for a filter. It should be understood that the second dechirping device 9542 can also be implemented with any other suitable components or devices, and the scope of this disclosure is not limited in this respect.

[0101] The second downconverter 9544 and the second filter 9546 can be configured in a similar manner to the first downconverter 9524 and the first filter 9526, and therefore will not be described further in this disclosure.

[0102] Local oscillator signal processing device 956 may include a local oscillator dechirping device 9562 and a local oscillator filtering device 9564. The local oscillator dechirping device 9562 is coupled to receiver 240 and FMCW signal generator 210 and is configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal. In some embodiments, the local oscillator dechirping device 9562 may include a down-converter. The echo signal may be input to the down-converter along with the current FMCW signal generated by FMCW signal generator 210 to dechirp the echo signal and obtain a local oscillator dechirped signal. Figure 7 Similar to the dechirped signal in the first signal, the local oscillator dechirped signal includes: the dechirped intermediate frequency signal component corresponding to the local oscillator signal, and the superposition of the dechirped intermediate frequency signal components corresponding to the two sidebands of the mixer signal and the signal components in the first signal.

[0103] For the intermediate frequency (IF) signal component obtained after dechirping corresponding to the local oscillator signal, since the frequency f1 of the fundamental signal component is usually much higher than the frequency of the IF signal, the local oscillator dechirped signal can be directly low-pass filtered using the local oscillator filter 9564 to obtain the local oscillator IF signal. The frequency of this local oscillator IF signal indicates the frequency difference between the local oscillator signal component in the current FMCW signal and the echo signal.

[0104] It should be understood that the processing of the local oscillator signal component can also be implemented in the first signal processing device 952 or the second signal processing device 954. Therefore, in some embodiments, the local oscillator signal processing device 956 can be omitted by configuring the first signal processing device 952 or the second signal processing device 954 accordingly, for example, by setting the passband frequency of the filter in the first dechirping device 9522 or the second dechirping device 9542 to include the local oscillator signal frequency. The scope of this disclosure is not limited in this respect.

[0105] The first set of intermediate frequency (IF) signals, the second set of IF signals, and the local oscillator (LO) IF signal output by the corresponding filtering devices can be sampled by the ADC 114 and then input together into the DSP 112 for processing. For speed measurement applications, any one of the multiple IF signals can be used. In other words, a sub-sweep bandwidth B of the total sweep bandwidth of the spread spectrum signal is used to determine the speed. For ranging applications, all the multiple IF signals can be spliced ​​in the DSP 112 to obtain an IF signal corresponding to the total sweep bandwidth of the spread spectrum signal. In other words, the entire sweep bandwidth of the spread spectrum signal can be used to determine the distance, thereby improving the distance resolution. In this way, the electronic circuit 900 according to the embodiments of this disclosure can increase the sweep bandwidth without increasing the sweep period, thereby achieving both high sweep bandwidth and low sweep period. Furthermore, compared with conventional solutions, the electronic circuit 900 according to the embodiments of this disclosure can operate using only one transmit RF channel and one receive RF channel, thus reducing hardware costs.

[0106] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of this disclosure and are not intended to limit the scope of this disclosure. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the claims and their equivalents.

Claims

1. An electronic circuit, characterized in that, The electronic circuit includes: A frequency modulated continuous wave (FMCW) signal generator is configured to generate FMCW signals; A spread spectrum device is configured to generate a spread spectrum signal based on the FMCW signal. The spread spectrum signal includes a first group of signal components and a second group of signal components. The sweep bandwidth and sweep period of the first group of signal components and the second group of signal components are the same as those of the FMCW signal, and the frequency band of the first group of signal components is not lower than that of the second group of signal components. A transmitter is configured to transmit the spread spectrum signal; A receiver is configured to receive an echo signal associated with the transmitted spread spectrum signal, the echo signal including a first set of signal components and a second set of signal components; and An echo signal processing device is configured to determine the frequency difference between the current FMCW signal of the FMCW signal generator and the first group of signal components and the second group of signal components of the echo signal, respectively.

2. The electronic circuit according to claim 1, characterized in that, The spread spectrum device includes: A first signal generator is configured to generate a first signal, the first signal including a fundamental signal component; and An upconversion device is configured to upconvert the first signal using the FMCW signal to generate the spread spectrum signal, the spread spectrum signal being composed of a first group of signal components and a second group of signal components, wherein the frequency of the first group of signal components is greater than the frequency of the FMCW signal and includes the sum of the frequency of the FMCW signal and the frequency of the fundamental signal component, and the frequency of the second group of signal components is less than the frequency of the FMCW signal and includes the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component; The frequency of the fundamental signal component is greater than or equal to half the sweep bandwidth of the FMCW signal.

3. The electronic circuit according to claim 2, characterized in that, The echo signal processing device includes: A first signal processing device is configured to extract a first group of signal components from the echo signal, and generate a first group of intermediate frequency (IF) signals based on the first group of signal components in the echo signal, the current FMCW signal, and the first signal, wherein the frequency of each IF signal in the first group of IF signals indicates the frequency difference between the current FMCW signal and a corresponding signal component in the first group of signal components in the echo signal; and A second signal processing device is configured to extract the second set of signal components from the echo signal and generate a second set of intermediate frequency (IF) signals based on the second set of signal components from the echo signal, the current FMCW signal, and the first signal, wherein the frequency of each IF signal in the second set of IF signals indicates the frequency difference between the current FMCW signal and the corresponding signal component in the second set of signal components from the echo signal.

4. The electronic circuit according to claim 3, characterized in that, The first signal processing device includes: A first dechirping device is configured to extract the first group of signal components in the echo signal and dechirp the first group of signal components in the echo signal using the current FMCW signal to obtain a first dechirped signal. A first down-conversion device is configured to down-convert the first dechirped signal using each signal component of the first signal to obtain a first set of down-converted signals; and A first filtering device is configured to perform low-pass filtering on the first group of down-conversion signals to obtain the first group of intermediate frequency signals; and The second signal processing device includes: The second dechirping device is configured to extract the second set of signal components in the echo signal and dechirp the second set of signal components in the echo signal using the current FMCW signal to obtain a second dechirped signal. The second down-conversion device is configured to down-convert the second dechirped signal using each signal component of the first signal to obtain a second set of down-converted signals; and The second filtering device is configured to perform low-pass filtering on the second group of down-converted signals to obtain the second group of intermediate frequency signals.

5. The electronic circuit according to claim 1, characterized in that, The spread spectrum device includes: A first signal generator is configured to generate a first signal, the first signal including a fundamental signal component and harmonic signal components; and An upconversion device is configured to upconvert the first signal using the FMCW signal to generate the spread spectrum signal, the spread spectrum signal being composed of a first group of signal components and a second group of signal components, the first group of signal components having a frequency greater than the frequency of the FMCW signal and including the sum of the frequencies of the harmonic signals and the FMCW signal, the second group of signal components having a frequency greater than the frequency of the FMCW signal and including the sum of the frequencies of the fundamental signal components and the FMCW signal; The frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal.

6. The electronic circuit according to claim 1, characterized in that, The spread spectrum device includes: A first signal generator is configured to generate a first signal, the first signal including a fundamental signal component and harmonic signal components; and An upconversion device is configured to upconvert the first signal using the FMCW signal to generate the spread spectrum signal, the spread spectrum signal being composed of a first group of signal components and a second group of signal components, the first group of signal components having a frequency lower than the frequency of the FMCW signal and including the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component, the second group of signal components having a frequency lower than the frequency of the FMCW signal and including the difference between the frequency of the FMCW signal and the frequency of the harmonic signal; The frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal.

7. The electronic circuit according to claim 5 or 6, characterized in that, The echo signal processing device includes: The dechirping device is configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal; A downconversion device is configured to downconvert the dechirped signal using each signal component of the first signal to obtain a set of downconverted signals; and A filtering device is configured to perform low-pass filtering on the set of down-converted signals to obtain a set of intermediate frequency signals, wherein the frequency of each intermediate frequency signal in the set of intermediate frequency signals indicates the frequency difference between the current FMCW signal and the corresponding signal component in the echo signal.

8. The electronic circuit according to claim 1, characterized in that, The spread spectrum device includes: A first signal generator is configured to generate a first signal, the first signal including a fundamental signal component having a first frequency; and An upconversion device is configured to upconvert the first signal using the FMCW signal to generate the spread spectrum signal, the spread spectrum signal being composed of a first group of signal components and a second group of signal components, the frequency of the first group of signal components being greater than the frequency of the FMCW signal and including the sum of the frequency of the FMCW signal and the frequency of the fundamental signal component, and the frequency of the second group of signal components being the frequency of the FMCW signal. The frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal.

9. The electronic circuit according to claim 8, characterized in that, The echo signal processing device includes: The dechirping device is configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal; The downconversion device is configured to downconvert the dechirped signal using each signal component in the first signal to obtain a set of downconverted signals; A first filtering device is configured to perform low-pass filtering on the set of down-converted signals to obtain a first set of intermediate frequency (IF) signals, wherein the frequency of each IF signal in the first set of IF signals indicates the frequency difference between the current FMCW signal and a corresponding signal component in the first set of signal components of the echo signal; and The second filtering device is configured to perform low-pass filtering on the dechirped signal to obtain a local oscillator intermediate frequency (LOIF) signal, the frequency of which indicates the frequency difference between the current FMCW signal and the second group of signal components in the echo signal.

10. The electronic circuit according to claim 1, characterized in that, The spread spectrum device includes: A first signal generator is configured to generate a first signal, the first signal including a fundamental signal component having a first frequency; and An upconversion device is configured to upconvert the first signal using the FMCW signal to generate the spread spectrum signal, the spread spectrum signal being composed of a first group of signal components and a second group of signal components, the frequency of the first group of signal components being the frequency of the FMCW signal, the frequency of the second group of signal components being less than the frequency of the FMCW signal, and including the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component; The frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal.

11. The electronic circuit according to claim 10, characterized in that, The echo signal processing device includes: The dechirping device is configured to dechirp the echo signal using the current FMCW signal to obtain a dechirped signal; A downconversion device is configured to downconvert the dechirped signal using each signal component of the first signal to obtain a set of downconverted signals; and A first filtering device is configured to perform low-pass filtering on the set of down-converted signals to obtain a first set of intermediate frequency signals, wherein the frequency of each intermediate frequency signal in the first set of intermediate frequency signals indicates the frequency difference between the current FMCW signal and the corresponding signal component in the second set of signal components in the echo signal. The second filtering device is configured to perform low-pass filtering on the dechirped signal to obtain a local oscillator intermediate frequency (LOIF) signal, the frequency of which indicates the frequency difference between the current FMCW signal and the second group of signal components in the echo signal.

12. The electronic circuit according to claim 1, characterized in that, The spread spectrum device includes: A first signal generator is configured to generate a first signal, the first signal including a fundamental signal component; and An upconversion device is configured to upconvert the first signal using the FMCW signal to generate the spread spectrum signal. The spread spectrum signal consists of a local oscillator signal component, a first group of signal components, and a second group of signal components. The frequency of the local oscillator signal component is the frequency of the FMCW signal. The frequency of the first group of signal components is greater than the frequency of the FMCW signal and includes the sum of the frequency of the FMCW signal and the frequency of the fundamental signal component. The frequency of the second group of signal components is less than the frequency of the FMCW signal and includes the difference between the frequency of the FMCW signal and the frequency of the fundamental signal component. The frequency of the fundamental signal component is greater than or equal to the sweep bandwidth of the FMCW signal.

13. The electronic circuit according to claim 12, characterized in that, The echo signal processing device includes: The local oscillator signal processing device is configured to generate a local oscillator intermediate frequency signal based on the echo signal, the current FMCW signal, and the first signal, wherein the frequency of the local oscillator intermediate frequency signal indicates the frequency difference between the local oscillator signal component in the current FMCW signal and the echo signal. A first signal processing device is configured to extract a first group of signal components from the echo signal, and generate a first group of intermediate frequency (IF) signals based on the first group of signal components in the echo signal, the current FMCW signal, and the first signal, wherein the frequency of each IF signal in the first group of IF signals indicates the frequency difference between the current FMCW signal and a corresponding signal component in the first group of signal components in the echo signal; and A second signal processing device is configured to extract the second set of signal components from the echo signal and generate a second set of intermediate frequency (IF) signals based on the second set of signal components from the echo signal, the current FMCW signal, and the first signal, wherein the frequency of each IF signal in the second set of IF signals indicates the frequency difference between the current FMCW signal and the corresponding signal component in the second set of signal components from the echo signal.

14. The electronic circuit according to claim 13, characterized in that, The local oscillator signal processing device includes: A local oscillator dechirping device is configured to dechirp the echo signal using the current FMCW signal to obtain a local oscillator dechirped signal; and The local oscillator filtering device is configured to perform low-pass filtering on the local oscillator dechirped signal to obtain the local oscillator intermediate frequency signal; The first signal processing device includes: A first dechirping device is configured to extract the first group of signal components in the echo signal and dechirp the first group of signal components in the echo signal using the current FMCW signal to obtain a first dechirped signal. A first down-conversion device is configured to down-convert the first dechirped signal using each signal component of the first signal to obtain a first set of down-converted signals; and A first filtering device is configured to perform low-pass filtering on the first group of down-conversion signals to obtain the first group of intermediate frequency signals; and The second signal processing device includes: The second dechirping device is configured to extract the second set of signal components in the echo signal and dechirp the second set of signal components in the echo signal using the current FMCW signal to obtain a second dechirped signal. The second down-conversion device is configured to down-convert the second dechirped signal using each signal component of the first signal to obtain a second set of down-converted signals; and The second filtering device is configured to perform low-pass filtering on the second group of down-converted signals to obtain the second group of intermediate frequency signals.

15. An electronic device, characterized in that, The electronic device includes: The electronic circuit according to any one of claims 1 to 14; and A power supply is configured to supply power to the electronic circuitry.

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