Signal transmitting link and method, transceiving link, integrated circuit and electromagnetic wave device

Abstract

A signal transmission link and method, a transceiver link, an integrated circuit, and an electromagnetic wave device are disclosed. The signal transmission link is applied in a radar system. The signal transmission link includes: a transmitting baseband digital module, a digital-to-analog converter (DAC) module, a transmitting local oscillator, and a transmitting quadrature modulator. The DAC module includes two identical DACs. The transmitting baseband digital module is configured to generate two orthogonal transmitting digital baseband signals and send the two orthogonal transmitting digital baseband signals to one DAC respectively. The DAC module is configured to convert the two orthogonal transmitting digital baseband signals into two transmitting analog baseband signals. The transmitting local oscillator is configured to provide a transmitting local oscillator signal. The transmitting quadrature modulator is configured to perform frequency shifting and phase shifting operations on the transmitting local oscillator signal based on the two transmitting analog baseband signals to form a predetermined phase-shifted FMCW radio frequency transmission signal.

Description

[0001] This application claims priority to Chinese Patent Application No. 202310702586.5, filed on June 14, 2023, entitled “Signal Transmission, Calibration, Compensation and Transceiver Link, IQ Mixer, Integrated Circuit, Sensor and Device”, the contents of which shall be construed as incorporated herein by reference. Technical Field

[0002] This disclosure relates to, but is not limited to, the field of electromagnetic wave device technology, and particularly to a signal transmission link and method, a transceiver link, an integrated circuit, and an electromagnetic wave device. Background Technology

[0003] At present, the transmitting (TX) end of frequency modulated continuous wave (FMCW) radar systems uses phase-locked loop (PLL) circuits to sweep the frequency, and then uses analog phase shifters, such as vector synthesis phase shifters and delay line phase shifters, to perform phase modulation.

[0004] However, analog phase shifters have low phase modulation resolution and accuracy, which limits system performance. For example, in automotive radar, under certain specific transmission systems, the low accuracy of analog phase shifters can affect target detection. Furthermore, analog phase shifters suffer from significant problems such as large area, high losses, poor stability, and channel coupling. When multiple antenna phase shifters work together, their performance can interfere with each other, further degrading system performance.

[0005] Offline calibration of analog phase shifters can improve their phase shifting accuracy and precision. However, the accuracy of offline calibration may vary depending on the chip's operating conditions (temperature). Furthermore, achieving higher phase shifting precision in analog phase shifters requires significantly more hardware investment. Summary of the Invention

[0006] The following is an overview of the subject matter described in detail herein. This overview is not intended to limit the scope of the claims.

[0007] This disclosure provides a signal transmission link applied in a radar system. The signal transmission link includes: a transmitting baseband digital module, a digital-to-analog converter (DAC) module, a transmitting local oscillator (LoLO), and a transmitting quadrature modulator. The DAC module includes two identical DACs. The transmitting baseband digital module is configured to generate two orthogonal transmitting digital baseband signals and send each of the two orthogonal transmitting digital baseband signals to one of the DACs. The DACs are configured to convert the two orthogonal transmitting digital baseband signals into two transmitting analog baseband signals. The transmitting LoLO is configured to provide a transmitting local oscillator signal. The transmitting quadrature modulator is configured to perform frequency shifting and phase shifting operations on the transmitting local oscillator signal based on the two transmitting analog baseband signals to form a predetermined phase-shifted FMCW radio frequency transmission signal.

[0008] This disclosure also provides a signal transmission link in an electromagnetic wave transmitting device, the signal transmission link including a first signal source and a digital phase shifting module; wherein the first signal source is configured to generate a first analog signal; and the digital phase shifting module is configured to perform frequency shifting and / or phase shifting on the first analog signal using digital quadrature modulation to form an FMCW radio frequency transmission signal.

[0009] This disclosure also provides a signal transceiver link, including a signal transmission link as described in any embodiment of this disclosure, and a signal reception link;

[0010] The signal receiving link includes a receiving local oscillator, a receiving mixer, an analog-to-digital converter, and a receiving baseband digital module. The receiving local oscillator is configured to provide a receiving local oscillator signal. The receiving mixer is configured to perform a mixing operation on the received echo signal based on the receiving local oscillator signal to obtain a receiving analog baseband signal. The echo signal is a signal formed by the reflection and / or scattering of the signal transmitted by the signal transmitting link by a target object. The analog-to-digital converter is configured to convert the receiving analog baseband signal into a receiving digital baseband signal. The receiving baseband digital module is configured to process the receiving digital baseband signal to achieve target detection and / or wireless communication.

[0011] This disclosure also provides an integrated circuit, including a signal transmission link as described in any embodiment of this disclosure, or a signal transceiver link as described in any embodiment of this disclosure.

[0012] This disclosure also provides an electromagnetic wave device, comprising: a carrier; an integrated circuit as described in any of the present disclosure, disposed on the carrier; an antenna disposed on the carrier, or the antenna and the integrated circuit are integrated into a single device disposed on the carrier; the antenna includes a transmitting antenna and a receiving antenna; wherein the integrated circuit is connected to the antenna and is used to transmit electromagnetic wave signals and / or receive electromagnetic wave signals.

[0013] This disclosure also provides an apparatus, including: an apparatus body; and an electromagnetic wave device disposed on the apparatus body as described in any embodiment of this disclosure; wherein the electromagnetic wave device is used for target detection and / or wireless communication to provide reference information to the operation of the apparatus body.

[0014] This disclosure also provides a signal transmission method applied to an electromagnetic wave device having at least one signal transmission link. The signal transmission method includes: determining the phase of a radio frequency transmission signal in each of the signal transmission links; determining an initial phase of a transmitting digital baseband signal in each of the signal transmission links based on the phase of the radio frequency transmission signal; generating the transmitting digital baseband signal based on the determined initial phase; converting the transmitting digital baseband signal into a transmitting analog baseband signal; and performing a phase shift operation on a transmitting local oscillator signal based on the transmitting analog baseband signal.

[0015] This disclosure also provides a non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a processor, cause the processor to perform a signal transmission method as described in any embodiment of this disclosure.

[0016] The signal transmission link and method, transceiver link, integrated circuit, and electromagnetic wave device of this disclosure are as follows: A transmitting-end baseband digital module generates two orthogonal transmitting-end digital baseband signals; a digital-to-analog converter converts the two orthogonal transmitting-end digital baseband signals into two transmitting-end analog baseband signals; a transmitting-end quadrature modulator performs frequency shifting and phase shifting operations on the transmitting-end local oscillator signal based on the two transmitting-end analog baseband signals to form a predetermined phase-shifted FMCW radio frequency transmission signal. This realizes a radar system with high-precision digital phase shifting function, reduces the isolation requirement between antennas, and has the advantages of low link loss, low cost, and no need for offline calibration. It also supports more flexible transmission schemes, such as high-performance Doppler Division Multiplexing (DDM) and Frequency Division Multiplexing (FDM), and can support frequency response compensation in the digital domain.

[0017] After reading and understanding the accompanying diagrams and detailed descriptions, other aspects can be understood. Attached Figure Description

[0018] The accompanying drawings are provided to further illustrate the technical solutions of this disclosure and form part of the specification. They are used together with the embodiments of this disclosure to explain the technical solutions of this disclosure and do not constitute a limitation on the technical solutions of this disclosure. The shapes and sizes of the components in the drawings do not reflect actual proportions and are only intended to illustrate the content of this disclosure.

[0019] Figure 1A A simplified schematic diagram of the signal transmission link simulating a phase shifter architecture;

[0020] Figure 1B for Figure 1A A simplified schematic diagram of an analog phase shifter in the signal transmission link is shown.

[0021] Figure 2 A schematic diagram of a signal transmission link provided as an exemplary embodiment of this disclosure;

[0022] Figure 3 This is a schematic diagram of the waveforms of the transmitted and echo signals of an FMCW using sawtooth wave modulation.

[0023] Figure 4 A schematic diagram of another signal transmission link provided as an exemplary embodiment of this disclosure;

[0024] Figure 5 This is a schematic diagram of a digital phase shifter architecture in a signal transmission link according to an embodiment of this application;

[0025] Figure 6 This is a schematic diagram of a signal transmission link including a compensation unit according to an embodiment of this application;

[0026] Figure 7 This is a schematic diagram illustrating the calibration and compensation of the transmit link using an auxiliary receiving circuit in an embodiment of this disclosure;

[0027] Figure 8 A schematic diagram of a signal transceiver link provided as an exemplary embodiment of this disclosure;

[0028] Figure 9 A schematic diagram of another signal transceiver link structure provided as an exemplary embodiment of this disclosure;

[0029] Figure 10 This is a schematic diagram of another transceiver link in an embodiment of this application;

[0030] Figure 11This is a schematic diagram of a transceiver link including TX IQ Mod, RX IQ De-Mod, and LO Freq Diff in an embodiment of this application;

[0031] Figure 12 This application provides an embodiment based on... Figure 11 The diagram shows a structure combined with the BIST transmit / receive link.

[0032] Figure 13 This is a schematic diagram of a transceiver link including TX IQ Mod, BIST IQ Mod and RX IQ De-Mod in an embodiment of this application;

[0033] Figure 14 This is a schematic diagram of a transceiver link including auxiliary circuitry and a BIST IQ Mod, as described in an embodiment of this application.

[0034] Figure 15 This is a schematic diagram of another transceiver link including auxiliary circuitry and a BIST IQ Mod in an embodiment of this application;

[0035] Figure 16 This is a schematic diagram of the structure of a mixer according to an embodiment of this application;

[0036] Figure 17 This is a schematic diagram of the structure of a compensation unit in a transmitter according to an embodiment of this application;

[0037] Figure 18 This is a schematic diagram of a digital pre-compensation HD3 architecture based on a cubic module in an embodiment of this application;

[0038] Figure 19 This is a schematic diagram of a digital pre-compensation HD3 architecture based on a frequency multiplier waveform generator module in an embodiment of this application;

[0039] Figure 20 This is a schematic diagram of calibration compensation for a transmit link based on a digital phase shifter architecture, as described in an embodiment of this application.

[0040] Figure 21 This is a schematic flowchart of a signal transmission method provided for an exemplary embodiment of the present disclosure. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this disclosure can be arbitrarily combined with each other.

[0042] Unless otherwise defined, the technical or scientific terms used in the embodiments of this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in the embodiments of this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" indicate that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, but do not exclude other elements or objects.

[0043] Radar is an electronic device that uses electromagnetic waves to detect targets. A radar chip transmits a beam through a signal transmission link. When the transmitted beam encounters an obstacle, the echo reflected back from the obstacle is received by a receiving antenna and transmitted to the radar chip. The radar chip then determines information such as the target's position, distance, and speed relative to the electromagnetic wave emission point. With the development of microelectronics and other technologies, radar has gradually gained widespread application, especially millimeter-wave radar (such as automotive radar). Due to its small antenna size, it has been widely used in autonomous driving, smart home devices, and industrial automation components. Currently, miniaturization and integration are the prevailing trends in radar development.

[0044] Figure 1A This is a simplified schematic diagram of the signal transmission link simulating a phase shifter architecture. Figure 1B for Figure 1A The diagram shows a simplified schematic of an analog phase shifter in the signal transmission link. Figure 1A As shown, for a transmission link, when the sensor transmits a signal, it generates a local oscillator (LO) signal (such as a frequency sweep signal in the 77GHz band), for example, an FMCW signal, through a signal generator 11 composed of a phase-locked loop (PLL). An analog phase shifter 12 performs a phase shift operation on the received LO signal, and then radiates it through a transmitting antenna 13 into a predetermined spatial area for target detection and measurement. Optionally, Figure 1A In the transmit link structure shown, the corresponding analog phase shifter architecture can be as follows: Figure 1B As shown, its specific phase-shifting principle can be expressed by the following formula:

[0045]

[0046] in

[0047] That is, by analyzing the received LO signal (i.e., LO) IN After performing phase shifts of 0° and 90° respectively, two signals (i.e., LO) are obtained. I and LO QThe signal is amplified by a power amplifier (PA) and then fitted into a single output signal LO. OUT That is, the output signal LO OUT Compared to LO IN The input signal is phase-shifted by θ, where the value of phase shift θ is determined by the two signals LO. I amplitudes A and LO Q The magnitude B is determined by this.

[0048] In addition, the analog phase shifter architecture described above can also be implemented using delay line units, that is, by utilizing the narrow-band assumption of the signal, phase shifting is performed through time delay, as shown in the following equation:

[0049]

[0050] Where τ is the delay time of the delay line.

[0051] The aforementioned analog phase shifters exhibit low resolution and accuracy, failing to meet the requirements of current sensors. While calibration can improve these aspects, it necessitates offline calibration of the analog phase shifters, significantly increasing the difficulty and complexity of engineering implementation and mass production. Furthermore, analog phase shifters suffer from significant drawbacks such as large area, high losses, and issues with stability and channel coupling.

[0052] Because the signal transmission link using an analog phase shifter architecture has problems such as low phase modulation accuracy and precision, it cannot meet the high-performance requirements of vehicle radar systems.

[0053] like Figure 2As shown, this disclosure provides a signal transmission link applied in a radar system. The signal transmission link includes: a baseband digital module 201, a digital-to-analog converter (DAC) module 202, a local oscillator 203, and a quadrature modulator 204. The DAC module 202 includes two identical DACs. The baseband digital module 201 is configured to generate two orthogonal transmission digital signals. The baseband signal is sent to a digital-to-analog converter module 202, which converts the two orthogonal digital baseband signals into two analog baseband signals. The local oscillator 203 is configured to provide the local oscillator signal TX_LO. The quadrature modulator 204 is configured to perform frequency shifting and phase shifting on the local oscillator signal TX_LO based on the two analog baseband signals to form a predetermined phase-shifted FMCW radio frequency transmission signal.

[0054] In this embodiment of the present disclosure, the transmitting digital baseband signal provided by the transmitting baseband digital module 201 includes preset phase information; the digital-to-analog converter module 202 performs digital-to-analog conversion on the received transmitting digital baseband signal to convert the transmitting digital baseband signal into a transmitting analog baseband signal (without changing the phase information); the transmitting quadrature modulator 204 performs a mixing operation on the received transmitting analog baseband signal and the transmitting local oscillator signal TX_LO generated by the transmitting local oscillator 203 to achieve frequency shifting of the transmitting local oscillator signal based on the transmitting analog baseband signal while performing a preset phase shifting operation to form a predetermined phase-shifted FMCW radio frequency transmission signal.

[0055] The signal transmission link of this embodiment uses a digital phase shifter architecture consisting of a baseband digital module 201, a digital-to-analog converter module 202, and a quadrature modulator 204 at the transmitting end. Since the baseband signal of this architecture is generated in the digital domain, it has better orthogonality and lower sidelobes. Therefore, its phase shift phase can be generated very accurately, resulting in higher phase modulation accuracy. This realizes a vehicle radar system with high-precision digital phase shifting function, reduces the isolation requirement between antennas, and has the advantages of low link loss, low cost, no need for offline calibration, and can support more flexible transmission schemes, such as high-performance Doppler multiplexing and frequency multiplexing, and can support frequency response compensation in the digital domain.

[0056] In this embodiment of the disclosure, since the transmitting baseband digital module 201 provides digital signals, in order to further adapt to the signal characteristics, the transmitting modulator is set as an orthogonal modulator (IQ modulator), and the digital-to-analog converter module 202 is set as an orthogonal digital-to-analog converter (IQ DAC).

[0057] In this embodiment of the disclosure, the transmitting local oscillator 203 can be an architecture that includes a phase-locked loop (PLL) and can provide electromagnetic wave (e.g., laser, microwave, etc.) signals.

[0058] In some exemplary embodiments, the signal transmission link further includes a power amplifier (PA) 205, wherein the power amplifier 205 is configured to amplify the phase-shifted radio frequency signal and output the amplified signal to the transmitting antenna.

[0059] In some exemplary embodiments, the signal transmission link further includes a transmitting antenna 206, wherein the transmitting antenna 206 is configured to radiate the amplified signal toward a preset spatial region.

[0060] In this embodiment, the signal amplified by the power amplifier 205 can be radiated into a predetermined spatial region through a transmitter antenna 206 that is either integrated or external. That is, the transmitter local oscillator 203, the digital phase shifter, and the transmitter antenna 206 can be integrated into a single device or can be separate components. For example, the transmitter local oscillator 203 and the digital phase shifter can be integrated into a package to form a SoC chip, while the transmitter antenna 206 can be connected to the chip's peripheral ports and formed on a carrier such as a PCB board. In some optional embodiments, the transmitter antenna 206 can also be integrated into the chip package to form an AiP or AoP, creating a chip structure with an encapsulated antenna.

[0061] In some exemplary embodiments, the bandwidth of the sweep signal is above 2 GHz.

[0062] The electromagnetic waves emitted by the transmitting antenna of a frequency modulated continuous wave radar system are high-frequency frequency modulated continuous waves, and the echo signals received by the receiving antenna of the frequency modulated continuous wave radar system are electromagnetic waves reflected / scattered back by the target object. Figure 3 A schematic diagram of the waveforms of an exemplary FMCW transmit and echo signals is shown. Figure 3 As shown, the frequencies of the transmitted and echo signals change regularly with time. Frequency-modulated continuous waves are generally sawtooth or triangular in shape; this disclosure uses a sawtooth shape as an example. The electromagnetic wave within each frequency modulation period T is called a chirp, and the frequency of the signal in each chirp increases linearly with time. In the embodiments of this disclosure, the bandwidth B of a chirp is greater than or equal to 2 GHz.

[0063] In some exemplary embodiments, the transmitting digital baseband signal is a single-tone signal, and the transmitting local oscillator signal is a swept-frequency signal.

[0064] In this embodiment, the transmitting local oscillator 203 can be configured to provide FMCW signals in the centimeter wave band or millimeter wave band (such as 3.1GHz, 24GHz, 60GHz, 77GHz, etc.) of microwaves. The transmitting baseband digital module 201 can be configured to provide single-tone transmitting digital baseband signals at the MHz level (e.g., 3MHz to 5MHz, such as 3MHz, 4MHz, 5MHz, etc.). That is, the digital-to-analog converter module 202 performs digital-to-analog conversion on the MHz-level single-tone transmitting digital baseband signal to obtain a single-tone transmitting analog baseband signal in the corresponding frequency range. The transmitting quadrature modulator 204 can be configured to perform up-mixing or down-mixing operations on the received millimeter wave band FMCW signal based on the received single-tone transmitting analog baseband signal to achieve a preset phase shift operation on the FMCW signal.

[0065] For example, the FMCW signal in the 3.1 GHz band may include a sweep signal between 3.1 GHz and 10.6 GHz, such as 7.163-8.812 GHz; the FMCW signal in the 77 GHz band may include a sweep signal between 76 GHz and 81 GHz, or sweep signals between 76 GHz and 77 GHz, 77 GHz and 79 GHz, 79 GHz and 81 GHz, etc.

[0066] In some other exemplary embodiments, the transmitting digital baseband signal is a swept frequency signal, and the transmitting local oscillator signal is a single-tone signal.

[0067] In this embodiment of the disclosure, the transmitting local oscillator 203 can be configured to provide a single-tone transmitting local oscillator signal in the centimeter wave band or millimeter wave band (such as 3.1GHz, 24GHz, 60GHz, 77GHz, etc.) of microwaves. The transmitting baseband digital module 201 can be configured to provide a transmitting digital baseband FMCW signal at the MHz level (e.g., 3MHz to 5MHz, such as 3MHz, 4MHz, 5MHz, etc.). That is, the digital-to-analog converter module 202 performs digital-to-analog conversion on the MHz-level transmitting digital baseband FMCW signal to obtain a transmitting analog baseband FMCW signal in the corresponding frequency range. The transmitting quadrature modulator 204 can be configured to perform up-mixing or down-mixing operations on the received single-tone transmitting local oscillator signal in the centimeter wave band or millimeter wave band based on the received transmitting analog baseband FMCW signal, so as to realize the operation of preset phase shifting and frequency sweeping of the single-tone transmitting local oscillator signal.

[0068] For example, the local oscillator signal of the single-tone transmitter in the 3.1GHz band can be a single-tone analog signal in a fixed frequency band such as 3.1GHz, 5GHz, 6GHz, 8GHz, 10.6GHz; the local oscillator signal of the single-tone transmitter in the 77GHz band can be a single-tone analog signal in a fixed frequency band such as 76GHz, 77GHz, 78GHz, 79GHz, 80GHz, 81GHz.

[0069] In some exemplary embodiments, the signal transmission link further includes a low-pass filter (LPF) 207, disposed between the digital-to-analog converter module 202 and the transmitting quadrature modulator 204, configured to perform low-pass filtering on the transmitting analog baseband signal output by the digital-to-analog converter module 202 and output it to the transmitting quadrature modulator 204.

[0070] like Figure 2 As shown, the transmitting baseband digital module 201 generates two orthogonal digital baseband signals, namely the I-channel digital baseband signal and the Q-channel digital baseband signal, and sends the generated digital baseband signals to the digital-to-analog converter module 202 (containing two identical DACs, namely the IQ DAC), to obtain two analog baseband signals. Then, the two analog baseband signals are input to the low-pass filter 207 to filter out out-of-band noise signals, and then orthogonally modulated by the transmitting quadrature modulator 204 to obtain the modulated radio frequency signal. Finally, the modulated radio frequency signal is radiated out through the power amplifier 205 and the transmitting antenna 206.

[0071] In some exemplary embodiments, the signal transmission link may also include a Direct Digital Frequency Synthesizer (DDFS). Figure 2 (Not shown in the image), located between the transmitting baseband digital module 201 and the digital-to-analog converter module 202, the direct digital frequency synthesizer can be configured to realize at least one of the following signal waveforms and transmission methods based on the received source signal: CDM (Code-Division Multiplexing), DDM (Doppler Division Multiplexing), TDM (Time-Division Multiplexing), SDM (Space Division Multiplexing), CSD (Circuit Switch Data), and Digital IF (Digital Intermediate Frequency), so as to achieve flexible configuration of signal transmission form and transmission waveform.

[0072] like Figure 4 As shown, this embodiment of the disclosure also provides a signal transmission link. In the application of an electromagnetic wave transmitting device, the signal transmission link includes a first signal source 41 and a digital phase shifting module 42; wherein,

[0073] The first signal source 41 is configured to generate a first analog signal; and

[0074] The digital phase-shifting module 42 is configured to use digital quadrature modulation to frequency-shift and / or phase-shift the first analog signal to form an FMCW radio frequency transmission signal.

[0075] The signal transmission link provided in this embodiment includes a first signal source 41 and a digital phase shifting module 42. The first signal source 41 can be configured to provide a first analog signal, and the digital phase shifting module 42 can be configured to generate a phase-shifting signal in the digital domain. The digital phase shifting module 42 can also perform phase shifting on the first analog signal based on the generated phase-shifting signal to perform a preset phase shifting operation on the first analog signal.

[0076] In some exemplary embodiments, the first signal source 41 may be a transmitting local oscillator, and the first analog signal may be a transmitting intrinsic (LO) signal.

[0077] In some exemplary embodiments, the signal transmission link also includes a power amplifier (not shown) configured to amplify the FMCW radio frequency transmission signal.

[0078] In some exemplary embodiments, the signal transmission link further includes a transmission antenna 43 configured to radiate the power-amplified FMCW radio frequency transmission signal toward a predetermined area.

[0079] like Figure 4 As shown, in some optional embodiments, the signal transmission link may include a first signal source 41, a digital phase-shifting module (Digital PS) 42, and a transmitting antenna 43. Specifically, the first signal source 41 can be configured to provide a LO signal, and the digital phase-shifting module 42 can be configured to perform a preset phase-shifting operation on the received LO signal, so that the phase-shifted LO signal is radiated into a preset spatial region via the transmitting antenna 43. The first signal source 41 may also be an architecture including a phase-locked loop (PLL) to provide electromagnetic wave (e.g., laser, microwave) signals. The first signal source 41, digital phase-shifting module 42, and transmitting antenna 43 can be integrated into a single device or are separate components. For example, the first signal source 41 and digital phase-shifting module 42 can be integrated into a package to form a SoC chip, while the transmitting antenna 43 can be connected to the chip's peripheral ports and formed on a carrier such as a PCB board. In some optional embodiments, the transmitting antenna 43 can also be integrated into the chip package to form an AiP or AoP, a chip structure with an encapsulated antenna.

[0080] In some exemplary embodiments, the digital phase-shifting module 42 includes a second signal source 423, a digital-to-analog converter 422, and a mixer 421 connected in sequence; wherein,

[0081] The second signal source 423 is configured to generate the first digital signal;

[0082] The digital-to-analog converter module 422 is configured to convert the first digital signal into a second analog signal;

[0083] Mixer 421 is configured to frequency shift and / or phase shift the first analog signal based on the second analog signal to form an FMCW radio frequency transmit signal.

[0084] like Figure 4 As shown, the digital phase-shifting module 42 in this embodiment may include a mixer 421, a digital-to-analog converter (DAC) 422, and a second signal source (such as a digital baseband signal source) 423. Specifically, the second signal source 423 may be configured to provide a first digital signal; the DAC module 422 may be configured to perform digital-to-analog conversion on the received first digital signal to convert it into a second analog signal; and the mixer 421 may be configured to mix the received second analog signal with the received first analog signal from the first signal source 41 to achieve a phase-shifting operation on the first analog signal using the first digital signal. Optionally, when the signal transmission link provides a swept signal, such as an FMCW laser signal or an FMCW microwave signal, a swept transmission signal may be provided based on the first signal source 41, and / or a swept first digital signal may be provided based on the second signal source 423, so that after mixing by the mixer 421, a swept continuous wave signal is output.

[0085] In some alternative embodiments, based on Figure 4 The structure shown allows the first signal source 41 to be configured to provide FMCW signals (i.e., the first analog signal) in the centimeter-wave or millimeter-wave frequency bands (such as 3.1 GHz, 24 GHz, 60 GHz, 77 GHz, etc.) of microwaves. The second signal source 423 can be configured to provide a first digital signal at the MHz level (e.g., 3 MHz to 5 MHz, such as 3 MHz, 4 MHz, 5 MHz, etc.). That is, the digital-to-analog converter module 422 performs digital-to-analog conversion on the MHz-level first digital signal to obtain a second analog signal with the corresponding frequency range. The mixer 421 can be configured to perform up-mixing or down-mixing operations on the received millimeter-wave FMCW signal based on the received second analog signal with a fixed frequency band, so as to realize the operation of preset phase shifting of the FMCW signal.

[0086] In some optional embodiments, the centimeter wave signal in the 3.1 GHz band may include 3.1 GHz to 10.6 GHz, such as 3.1 GHz, 5 GHz, 6 GHz, 8 GHz, 10.6 GHz, etc.; the millimeter wave signal in the 77 GHz band may include signals in the 76 GHz to 81 GHz band, such as swept signals in the 76 GHz to 77 GHz, 77 GHz to 79 GHz, 79 GHz to 81 GHz bands, or fixed frequency band signals in the 76 GHz, 77 GHz, 78 GHz, 79 GHz, 80 GHz, 81 GHz bands.

[0087] In some exemplary embodiments, the first digital signal includes two orthogonal transmitting digital baseband signals;

[0088] The second signal source 423 is a transmitting baseband digital module, and the digital-to-analog conversion module 422 includes two identical digital-to-analog converters;

[0089] The transmitting baseband digital module is configured to generate two orthogonal transmitting digital baseband signals and send the two orthogonal transmitting digital baseband signals into a digital-to-analog converter respectively.

[0090] The digital-to-analog converter module 422 is configured to convert two orthogonal transmitting digital baseband signals into two transmitting analog baseband signals.

[0091] based on Figure 4 In the illustrated structure, since the second signal source 423 provides the first digital signal, to further adapt to the signal characteristics, the mixer 421 can be configured as an IQ mixer, and the digital-to-analog converter module 422 can be an IQ DAC. Simultaneously, the second signal source 423 can be configured to provide a digital baseband signal source (DDFS) for phase shifting and / or to provide a corresponding source signal as a waveform controller. The DDFS is a phase-adjustable digital baseband signal source that generates a digital baseband signal.

[0092] like Figure 5As shown, the signal transmission link (TX digital phase shifter architecture) of the digital phase shifter architecture may include a digital baseband signal source, a direct digital frequency synthesizer (DDFS), an IQ digital-to-analog converter (DAC), a low-pass filter (LPF), an IQ modulator / IQ mixer, and a power amplifier (PA). Specifically, the baseband signal source is configured to provide the digital phase-shifting source signal (i.e., the aforementioned first digital signal), and the direct digital frequency synthesizer can be configured to implement CDM (Code-Division Multiplexing), DDM (Doppler Division Multiplexing), TDM (Time-Division Multiplexing), SDM (Space Division Multiplexing), CSD (Circuit Switch Data), and Digital IF (Digital Intermediate Frequency Array) based on the received source signal. The system can utilize at least one of several signal waveforms and transmission methods, including frequency (digital intermediate frequency), to achieve flexible configuration of signal transmission form and waveform. The signal, amplified by a power amplifier, can be radiated into a predetermined spatial region via a transmitter antenna that is either integrated into a single unit or externally mounted.

[0093] Regarding the signal transmission link of the digital phase shifter architecture in this embodiment, since the digital phase shifter architecture is configured to generate a baseband signal sequence in the digital domain and generate an analog baseband signal (i.e., a second analog signal) through a DAC, and then modulate the transmitted signal to a high frequency through an orthogonal mixer, the baseband signal of this architecture is generated in the digital domain, which has better orthogonality and lower sidelobes. Therefore, its phase shift phase can be generated very accurately, resulting in higher phase modulation accuracy.

[0094] In some optional embodiments, for the signal transmission link of a digital phase shifter architecture, when RF LO sweep is used to implement the transmitted signal as an FMCW signal, a compensation unit can be added to the signal transmission link to address potential problems such as TX IQ imbalance (imbalance), signal leakage (e.g., TX LO leakage), and harmonic distortion (HD) caused by IQ mismatch. For example... Figure 5 As shown, by setting a TX compensation unit between the TX DDFS and the IQ DAC, the signal transmission link of the digital phase shifter architecture can be calibrated and compensated, thereby solving at least one of the aforementioned problems. The HD caused by the third-order nonlinearity of the baseband can be simply referred to as HD3.

[0095] In some alternative embodiments, such as Figure 6 As shown, the TX compensation unit may include at least one of a TX LO leakage compensation unit, a TX IQ imbalance compensation unit, and a TX HD3 compensation unit. The TX LO leakage compensation unit can be configured to compensate for signal leakage, the TX IQ imbalance compensation unit can be configured to compensate for IQ imbalance, and the TX HD3 compensation unit can be configured to compensate for HD3 imbalance. The TX LO leakage compensation unit is configured to compensate for at least one of IQ modulator imbalance and IQ channel imbalance. Furthermore, when the compensation unit includes at least two of the TX LO leakage compensation unit, TX IQ imbalance compensation unit, and TX HD3 compensation unit, compensation can be performed synchronously (e.g., in parallel) or sequentially (e.g., in series) according to actual needs and signal characteristics. Figure 6 As shown, IQ compensation can be performed first, followed by LO compensation, and finally HD3 compensation.

[0096] In some optional embodiments, the signal transmission link for the digital phase shifter architecture may also include an error correction module for the DAC (TX DAC Board Error Correction) and an AWGN (additive white Gaussian noise) module, etc., which are not shown in the figure. These can be added or removed according to actual needs. In the embodiments of this disclosure, IQ can represent In-Phase, Q can represent Quadrature, and RF can represent Radio Frequency.

[0097] In an optional embodiment, compensation for IQ Imbalance can be achieved by compensating for the conjugate signal of the BB (baseband) signal to inversely cancel the image component, and this compensation method is unaffected by the IQ Imbalance calibration method. Compensation for LO Leakage can be achieved by adjusting the DC components (i.e., DC bias) of the IQ channels; similarly, the LO Leakage calibration method does not affect its compensation scheme. Regarding HD3, since the third harmonic distortion of the quadrature mixer V / IConverter is the main source of HD3, and harmonic distortion is affected by DC bias, when both the LO Leakage and HD3 of the transmit link require calibration, HD3 calibration should be performed after LO Leakage calibration to ensure the accuracy of HD3 calibration.

[0098] Furthermore, the compensation methods of HD3, based on the digital pre-compensation architecture of the digital cube module and the digital pre-compensation architecture of the frequency multiplier waveform generator module, directly affect the subsequent calibration scheme and compensation process. Specifically:

[0099] In an optional embodiment, for a digital pre-compensation architecture based on a digital cubic module, the LO leakage can be calibrated and compensated first. Under a stable DC bias, the root cause of the HD3 problem, namely the HD3 compensation coefficient, can be calibrated. Then, the IQ Imbalance can be calibrated and compensated. After that, the third harmonic distortion can be compensated for on both the IQ and IQ paths based on the pre-compensation results of the IQ Imbalance.

[0100] In an optional embodiment, for a digital pre-compensation architecture based on a frequency multiplier waveform generator module, after calibrating and compensating for LO leakage, the compensation coefficient of HD3 can be calibrated, and IQ Imbalance can be calibrated and compensated under a stable DC bias. Subsequently, based on the compensation results, the actual waveforms of the IQ signals and the compensation coefficient of HD3 can be calculated respectively, and the waveform information of the 3rd and 5th harmonic frequencies that need to be pre-compensated can be calculated.

[0101] In another optional embodiment, for a digital pre-compensation architecture based on a frequency harmonic waveform generator module, the LO leakage can be calibrated and compensated first. Then, the pre-compensation coefficients for HD3 and IQ Imbalance can be simultaneously calibrated through multiple (e.g., three) observations. Afterward, the pre-compensation coefficients at the HD3 mirror position can be calibrated through further observations (e.g., two). Finally, the 3rd and 5th harmonic coefficients requiring pre-compensation can be calculated using the pre-compensation coefficients at HD3 and its mirror position. It should be noted that the observations in this embodiment are used to represent testing and comparative analysis of different test results.

[0102] Figure 7 This is a schematic diagram illustrating the use of an auxiliary receiving circuit to calibrate and compensate the transmission link in an embodiment of this disclosure.

[0103] like Figure 7 As shown, the transmitter may include a phase shifter module (PS), a power amplifier (PA), a power detector (PD), etc. For example, the transmitter may adopt the signal transmission link of the digital phase shifter architecture described in any embodiment of this disclosure, as detailed in the relevant figures and text descriptions, which will not be repeated here. Because the transmitter uses a digital phase shifter architecture, it can achieve more precise phase shifting operations while simultaneously supporting multiple modes such as DDM and FDM (Frequency Division Multiplexing) for multiple antennas. It also eliminates the need for RF phase shifter calibration, reducing isolation and coupling in the phase shifting system, and decreasing link loss and manufacturing costs. Furthermore, to address potential issues such as TX IQ mismatch and LO leakage, the transmitter of this digital phase shifter architecture can also support RF frequency response compensation, IQ imbalance, and LO leakage calibration operations in the digital domain.

[0104] To address issues such as TX-IQ mismatch, LO leakage, and frequency response in the transmission path, calibration and compensation operations can be performed by setting up an auxiliary receiver (ARX). For example... Figure 7 As shown, the ARX can include a mixer, TIA, LPF, HPF, IQ ADC, adder, and RF calibration module (RF Calib) connected in sequence. Specifically, it receives the ARX IQ LO signal at one input of the mixer, and connects the other input to a node before the transmit path PD along the signal transmission direction (i.e., the direction of the arrow shown in the figure), or to any node after the phase shifter (module). For example, it can be connected to the output of the PA (to synchronously calibrate the PA), the input of the PA, etc., to perform calibration operations on the transmit path through the ARX. The LO signal frequency in the transmit path and the ARX IQ LO signal frequency have a set difference frequency to create a frequency misalignment between the two signals, simulating a real transmit / receive signal loop.

[0105] In an optional embodiment, to further improve calibration accuracy, a corresponding calibration circuit (i.e., calibration receiving unit) can also be provided for the ARX (i.e., auxiliary receiving unit), for example... Figure 7 The RF tone generator circuit shown may include a TX DDFS, an adder, a Real DAC, an LPF, an amplifier, a multiplier, and a band-pass filter (BPF) connected in sequence. The adder can be configured to compensate for TX LO leakage waveform, while the multiplier can be configured to compensate for RF tone generator LO leakage. The BPF can be configured to filter out the DC signal generated by the LO leakage of the RF tone generator. In other words, the RF tone generator can be configured to generate multiple stable tone signals of different frequencies to achieve ARX calibration.

[0106] In some alternative embodiments, such as Figure 7 As shown, the ARX can be calibrated first using the RF Tone Generator, and then the calibrated ARX can be used to calibrate the transmitter, including devices and circuits such as the PD at the PA output, the phase shifter in the transmitter, the total gain from the DAC to the PA output, and the frequency response.

[0107] Specifically, such as Figure 7As shown, multiple stable single-tone signals of different frequencies can be generated first using an RF Tone Generator to assist in calibrating the ARX. Then, based on the calibrated ARX, the IQ imbalance, local oscillator leakage, and inconsistent frequency response of the transmit path TX can be calibrated.

[0108] This disclosure also provides a signal transceiver link, including a signal transmission link and a signal reception link, such as... Figure 8 or Figure 9 As shown, the signal transmission link may include: a transmitting baseband digital module 201, a digital-to-analog converter module 202, a transmitting local oscillator 203, and a transmitting quadrature modulator 204, wherein: the transmitting baseband digital module 201 is configured to generate two orthogonal transmitting digital baseband signals and send the generated transmitting digital baseband signals into the digital-to-analog converter module 202; the digital-to-analog converter module 202 is configured to convert the transmitting digital baseband signals into transmitting analog baseband signals; the transmitting local oscillator 203 is configured to provide a transmitting local oscillator signal TX_LO; and the transmitting quadrature modulator 204 is configured to perform a phase-shifting operation on the transmitting local oscillator signal TX_LO based on the transmitting analog baseband signal to obtain a phase-shifted radio frequency signal.

[0109] The signal receiving link may include a receiving local oscillator 302, a receiving mixer 303, an analog-to-digital converter (ADC) 304, and a receiving baseband digital module 305. The receiving local oscillator 302 is configured to provide a receiving local oscillator signal. The receiving mixer 303 is configured to perform a mixing operation on the received echo signal based on the receiving local oscillator signal to obtain a receiving analog baseband signal. The ADC 304 is configured to convert the receiving analog baseband signal into a receiving digital baseband signal. The receiving baseband digital module 305 is configured to process the receiving digital baseband signal to achieve target detection and / or wireless communication, for example, obtaining parameter information of the target such as distance, speed, angle, height, and micro-motion characteristics.

[0110] In this embodiment of the disclosure, the two ideal I-channel digital baseband signals and Q-channel digital baseband signals generated by the transmitting baseband digital module 201 are converted into a highly ideal complex signal by the digital-to-analog converter module 202, and the phase of this complex signal can be precisely controlled by the transmitting baseband digital module 201. Through, as shown in... Figure 8 Or such as Figure 9 The receiver structure shown in the signal transceiver link can effectively acquire the phase information of the radio frequency signal in the signal transmission link, thereby enabling phase modulation of multiple antennas.

[0111] In some exemplary embodiments, the signal transmission link may further include a power amplifier 205, wherein the power amplifier 205 is configured to amplify the phase-shifted radio frequency signal and output the amplified signal to the transmitting antenna.

[0112] In some exemplary embodiments, the signal transmission link may further include a transmitting antenna 206, wherein the transmitting antenna 206 is configured to radiate the amplified signal to a preset spatial region.

[0113] In some exemplary embodiments, the signal receiving link may further include a receiving antenna 301, wherein the receiving antenna 301 is configured to receive an echo signal, which is a signal formed by the reflection and / or scattering of a signal emitted by the signal transmitting link by a target object.

[0114] In some exemplary embodiments, the receiving end local oscillator signal can be a swept frequency signal, or the receiving end local oscillator signal can be a single-tone signal.

[0115] In this embodiment of the disclosure, in the aforementioned signal transceiver link, the frequencies of the TX-LO signal received by the transmitting quadrature modulator 204 in the signal transmitting link and the RX-LO signal received by the receiving mixer 303 in the signal receiving link can be the same. For example, assuming the signal output by the transmitting baseband digital module 201 is a sine wave of x MHz, then the TX-LO signal and the RX-LO signal can both be sine waves of z GHz, where x and z are both positive numbers, generally between 0 and 1000.

[0116] The following is through Figure 8 The signal transmission link shown illustrates the principle of this disclosure. As previously mentioned, for an FMCW radar system, the signal transmission link can have two transmission schemes: 1) frequency sweep of the local oscillator signal at the transmitting end and single tone of the digital baseband signal at the transmitting end; 2) single tone of the local oscillator signal at the transmitting end and frequency sweep of the digital baseband signal at the transmitting end. Assuming the local oscillator signal TX_LO, the digital baseband signal at the transmitting end, and the modulated transmitted signal are represented by TLO(t), BB(t), and TX(t) respectively, and the subscripts I and q represent the I-channel signal and the Q-channel signal, and the superscript a represents their complex signal form, then under the two transmission schemes, the signals at each stage of the signal transmission link can be represented as follows:

[0117] 1) Frequency sweep of the local oscillator signal at the transmitting end, single tone of the digital baseband signal at the transmitting end.

[0118]

[0119]

[0120]

[0121]

[0122] 2) The local oscillator signal at the transmitting end is a single tone, and the digital baseband signal at the transmitting end is a frequency sweep.

[0123]

[0124]

[0125]

[0126]

[0127] in, f is the sweep slope of the FMCW signal. bb f is the starting frequency of the transmitted digital baseband signal. tlo The starting frequency of the local oscillator signal is the frequency at which the signal is generated. The initial phase of the transmitted digital baseband signal. This represents the initial phase of the originating local oscillator signal.

[0128] Assumption Figure 8 The received local oscillator signal RX_LO in the signal receiving link shown is represented by RLO(t). In this embodiment, assuming that the received local oscillator signal RX_LO is a frequency sweep signal, RLO(t) can be expressed as:

[0129]

[0130] Among them, f rlo Let Φ0 be the starting frequency of the received local oscillator signal and Φ0 be the initial phase of the received local oscillator signal. Then, the radio frequency signal transmitted by the signal transmission link generates an echo signal after being reflected / scattered by the target. After passing through the receiving antenna 301, the receiving mixer 303, and the receiving low-pass filter 307, the following can be obtained:

[0131]

[0132] Where τ represents the time delay of the radio frequency signal transmitted by the signal transmission link returning to the signal reception link after being reflected / scattered by the target.

[0133] The above formula illustrates that both frequency sweeping methods can control the initial phase of the transmitted digital baseband signal. This allows for precise phase modulation, achieving high-precision and high-accuracy phase shifting, thus avoiding direct phase shifting at high frequencies.

[0134] In some alternative embodiments, the receiving antenna 301 can be connected via the chip's peripheral port and formed on a carrier such as a PCB board. Meanwhile, in other alternative embodiments, the receiving antenna can also be integrated into the chip package to form an AiP or AoP, i.e., a chip structure with an encapsulated antenna.

[0135] In some exemplary embodiments, the signal receiving link may also include a low noise amplifier (LNA) 306, which is disposed between the receiving antenna 301 and the receiving mixer 303 to amplify the echo signal received by the receiving antenna 301 with low noise before sending it to the receiving mixer 303.

[0136] In some exemplary embodiments, the signal receiving link may further include a low-pass filter (LPF) 307 and a high-pass filter (HPF) 308 connected in series, disposed between the receiving mixer 303 and the analog-to-digital converter 304. The low-pass filter 307 and the high-pass filter 308 form a band-pass filter for filtering out out-of-band noise.

[0137] In some exemplary implementations, such as Figure 8 As shown, in the signal receiving link, the receiving mixer 303 can be a real number mixer, and the analog-to-digital converter 304 can be a real number analog-to-digital converter.

[0138] In this embodiment of the disclosure, although the signal transmission link adopts a digital phase-shifting architecture, the signal receiving link may include receivers with orthogonal or non-orthogonal receiving architectures. Therefore, it can effectively be compatible with sensors of various receiving link architectures, effectively reducing the development cost of the entire transceiver link system.

[0139] In other exemplary embodiments, such as Figure 9 As shown, in the signal receiving link, the receiving mixer 303 can be an orthogonal mixer, and the analog-to-digital converter 304 can be an orthogonal analog-to-digital converter.

[0140] To match the signal transmission link of the digital phase shifter architecture, this embodiment adjusts the receiving mixer 303 in the signal receiving link to an IQ demodulator, and the analog-to-digital converter 304 to an IQ ADC. The echo signal received by the receiving antenna is processed sequentially by the low-noise amplifier 306, the receiving mixer 303, the low-pass filter 307, the high-pass filter 308 and the analog-to-digital converter 304 to be converted into an IQ digital baseband signal. The subsequent receiving baseband digital module 305 processes the IQ digital baseband signal to obtain parameter information of the target such as distance, speed, angle, height and micro-motion characteristics (i.e. micro-Doppler).

[0141] When the receiving mixer 303 is a quadrature mixer and the receiving local oscillator signal is a swept frequency signal, the receiving local oscillator signal RX_LO can be expressed as:

[0142]

[0143] In some other exemplary embodiments, the local oscillator signal at the receiving end of the signal receiving link may be a sweep signal as shown in equation (9) or equation (11), or a single-tone signal as shown in equation (12) or equation (13).

[0144] The receiving mixer 303 is a real number mixer: RLO(t) = cos(2πf) rlo t+Φ0)(12).

[0145] The receiving mixer 303 is a quadrature mixer:

[0146] When the local oscillator signal at the receiving end is a single-tone signal, the required digital baseband signal can be obtained simply by adding a digital domain signal processing procedure (including digital domain mixing operation) to the baseband digital module 305 at the receiving end.

[0147] In summary, the embodiments of this disclosure can be extended to various system-level technical solutions by combining different transmission and reception schemes (for example, whether the transmitting end uses a digital baseband signal single tone, a local oscillator signal frequency sweep, or a digital baseband signal frequency sweep and a local oscillator signal single tone; whether the receiving end uses a real number mixer, a real number analog-to-digital converter, or a quadrature mixer and a quadrature analog-to-digital converter; whether the receiving end uses a single tone local oscillator signal or a frequency sweep local oscillator signal).

[0148] Figure 10 This is a schematic diagram of another transceiver link in an embodiment of this application. Figure 11 This is a schematic diagram of a transceiver link including TXIQ Mod, RX IQ De-Mod, and LO Freq Diff in an embodiment of this application. Figure 12 This application provides an embodiment based on... Figure 11 The diagram shown is a schematic of the BIST transmit / receive link structure. Figure 13 This is a schematic diagram of a transceiver link including TXIQMod, BIST IQ Mod and RX IQ De-Mod in an embodiment of this application.

[0149] The following description focuses on the transmit / receive link structure described in the embodiments of this application:

[0150] like Figure 10As shown, a transceiver link may include a transmit link and a receive link. The transmit link (i.e., the transmitter) may include a digital baseband signal source, a direct digital frequency synthesizer (TXDDFS), an IQ digital-to-analog converter (IQ DAC), a low-pass filter (LPF), an IQ modulator, a power amplifier (PA), etc., connected in sequence. The signal amplified by the power amplifier is radiated to a predetermined spatial area via a transmit antenna. The receiving link may include a low noise amplifier (LNA), a real mixer, a trans-impedance amplifier (TIA), a low-pass filter (LPF), a high-pass filter (HPF), and a real digital-to-analog converter (Real ADC) connected in sequence. That is, the echo signal received by the receiving antenna is processed by the LNA, Real Mixer, TIA, LPF, HPF and Real ADC in sequence and converted into a real digital baseband signal. The subsequent digital signal processing module can process the real digital baseband signal to obtain the target's parameter information such as distance, speed, angle, height and micro-motion characteristics.

[0151] In the aforementioned transceiver link, the frequencies of the TX-LO signal received by the IQ modulator in the transmit link and the RX-LO signal received by the Real Mixer in the receive link can be the same. For example, as... Figure 10 As shown, if the Baseband output signal is a sine wave of x MHz, then the TX-LO signal and the RX-LO signal can both be sine waves of z GHz.

[0152] exist Figure 10 In the embodiment shown, the transmit link adopts a digital phase-shifting architecture, while the receive link can use analog architecture components, that is, it does not need to use IQ components. Therefore, it can effectively be compatible with the sensors of the analog architecture receive link, effectively reducing the development cost of the entire transceiver link system.

[0153] Optionally, in embodiments of this application, the receiving link may include a receiving antenna, which can be connected via the chip's peripheral port and formed on a carrier such as a PCB board. Additionally, in some optional embodiments, the receiving antenna may be integrated into the chip package to form an AiP or AoP, i.e., a chip structure with an encapsulated antenna.

[0154] In some alternative embodiments, to match the transmit link of the digital phase shifter architecture, corresponding adjustments can be made to the receive link, such as... Figure 11 The transceiver link shown may include components based on... Figure 10 Similar transmit link architecture and receive link (to avoid redundancy, the identical parts will not be described here), will Figure 10 In the receiving link, the Real Mixer is adjusted to an IQ Demodulator, and the Real ADC is adjusted to an IQ ADC. At this time, the receiving link can include a low-noise amplifier (LNA), an IQ demodulator, a transimpedance amplifier (TIA), a low-pass filter (LPF), a high-pass filter (HPF), and an IQ digital-to-analog converter (IQADC) connected in sequence. The echo signal received by the receiving antenna is processed by the LNA, IQ Demodulator, TIA, LPF, HPF and IQ ADC in sequence and converted into an IQ digital baseband signal. The subsequent digital signal processing module can process the IQ digital baseband signal to obtain target parameters such as distance, speed, angle, height and micro-motion characteristics (i.e. micro Doppler).

[0155] At the same time, based on Figure 11 When the transmit / receive link shown performs self-calibration, it is sufficient to directly connect the signal output port of the transmit link to the signal input port of the receive link via a transmission line. That is, the transmit link directly sends the transmitted signal to the receive link through this transmission line, thus achieving self-calibration of the transmit and / or receive links without using transmit and receive antennas. In this case, there is a certain frequency offset between the TX-LO signal received by the IQ modulator in the transmit link and the RX-LO signal received by the IQ Demodulator in the receive link. For example, as... Figure 11 As shown, if the Baseband output signal is a sine wave of x MHz, then the TX-LO signal can be a sine wave of z GHz. In this case, the RX-LO signal is converted into a digital signal after being processed by a down-mixer (i.e., the IQ Demodulator in the receiving link), low-pass filtering, and high-pass filtering, so as to perform TX IQ imbalance calibration.

[0156] In some alternative embodiments, such as Figure 11As shown, the transmitting link (Transmitter, TX) can be calibrated by adding a receiving link (Receiver, RX as shown in the figure), and compensation can be performed based on the calibrated data by the TXIQ imbalance compensation unit in the transmitting link. Alternatively, the transmitting link (Transmitter, TX) can be calibrated by multiplexing the receiving link actually used for signal transmission and reception (Receiver, RX as shown in the figure), and compensation can be performed based on the calibrated data by the TXIQ imbalance compensation unit in the transmitting link and / or the receiving link. Figure 11 This is for signal links with TX IQ imbalance. Since the operating principle of a signal link with TX harmonic signal problems is similar to that of a signal link with TX IQ imbalance, it can be... Figure 11 The TX IQ imbalance compensation unit is replaced with a TX HD3 compensation unit to address the TX HD3 issue. Similar implementations can be performed in other embodiments, but for simplicity, they will not be elaborated upon further.

[0157] In some alternative embodiments, based on Figure 11 Based on the structure shown, in order to achieve accurate calibration of the transmit and receive links, Figure 11 The received link's IQ Demodulator RX-LO port is configured with an internal self-test module (Built-in Self-Test, BIST) module, as shown below. Figure 12 As shown, in Figure 11 Based on the transceiver link structure shown, an IQ BIST architecture is configured at the RX-LO port of the IQDemodulator in the receiving link to achieve an input LO signal with a preset frequency offset at the RX-LO port of the IQDemodulator in the receiving link. For example, an IQ BIST, constructed using a phase angle converter and an IQ modulator, utilizes a received signal such as TX-LO, which is converted from a phase angle converter to an IQ modulator. The resulting signal is frequency-biased based on the frequency offset of another input signal, BIST-LO, from the IQ modulator and input to the RX-LO port of the IQDemodulator. For example, if the TX-LO signal is a sine wave of z GHz and the BIST-LO signal is a sine wave of y MHz, then the frequency-biased signal input to the RX-LO port of the IQ Demodulator is (z GHz - y MHz). It should be noted that x, y, and z are illustrative values ​​in different embodiments, and their specific values ​​may be the same or different.

[0158] In some alternative embodiments, based on Figure 12The IQ BIST architecture of the transceiver link structure shown can also calibrate the transmit link of the digital phase shifter architecture by reusing the receive link in the transceiver link. In other embodiments, the calibration operation involving the transmit link using the receive link and the calibration operation involving the receive link using the transmit link can be achieved by reusing the corresponding receive link or transmit link in the actual link for signal transmission and reception, or by adding a corresponding calibration receive link or calibration transmit link to achieve the calibration operation of the corresponding transmit link or receive link in the actual link for signal transmission and reception.

[0159] Optionally, the IQBIST may include a phase angle converter and an IQ modulator. The phase angle converter is used to calibrate the I and Q paths in the transmit link of the digital architecture separately, while the other input signal of the IQ modulator, BIST-LO, can be a y MHz sine wave to simulate the characteristics of the echo signal formed by the reflection of the transmitted signal from the target. Figure 12 In this case, x, y, and z are all positive numbers, and x ≠ y ≠ z, generally ranging from 0 to 1000.

[0160] Optional, in Figure 12 In the transmit / receive link shown, a TX IQ Imbalance Compensation unit can also be set in the transmit link (e.g., between the TXDDFS and the IQ DAC) and / or in the receive link (e.g., after the Real ADC). This allows the transmitted and / or received signals to be supplemented based on the calibration parameters (or coefficients) obtained from the self-calibration operation described above, thereby solving problems such as IQ imbalance.

[0161] In some alternative embodiments, based on Figure 12 The structure shown is as follows: Figure 13 As shown, the IQ BIST module can be placed between the signal output port of the transmit link and the signal input port of the receive link. That is, the transmit link directly sends the transmit signal to the receive link through the IQ BIST module, so as to realize the self-calibration operation of the receive link and / or transmit link without passing through the transmit antenna and the receive antenna.

[0162] It should be noted that, in Figures 11 to 13The transmission link structure shown only illustrates the IQ compensation unit (TXIQImbalance compensation). In practical applications, LO compensation units (TXLO leakage compensation) and HD3 compensation units (TXHD3 compensation) can be added to the transmission link based on actual needs to form a compensation unit (TXcompensation) that includes LO compensation units (TX LO leakage compensation), IQ compensation units (TX IQImbalance compensation) and / or HD3 compensation units (TX HD3 compensation).

[0163] Figure 14 This is a schematic diagram of a transceiver link including auxiliary circuitry and a BIST IQ Mod, as described in an embodiment of this application. Figure 15 This is a schematic diagram of another transceiver link including auxiliary circuitry and a BIST IQ Mod in an embodiment of this application.

[0164] like Figure 14 As shown, a transceiver link, combined with Figure 9 and Figure 13The structure and related descriptions shown indicate that the transceiver link may include a transmit link, a receive link, and a calibration link. The transmit link may include, in sequence, a TX digital baseband signal source (TX Baseband), a direct digital frequency synthesizer (TX DDFS), a compensation unit, an IQ digital-to-analog converter (IQDAC), a low-pass filter (LPF), an IQ modulator, and a power amplifier (PA). The signal amplified by the power amplifier is then radiated through a transmit antenna to a predetermined spatial region. The receiving link may include a low noise amplifier (LNA), a real mixer, a trans-impedance amplifier (TIA), a high-pass filter (HPF), a variable gain amplifier (VGA), a real-to-digital converter (RealADC), and an RX baseband for TXRF calibration, connected in sequence. That is, the echo signal received by the receiving antenna is processed by the LNA, Real Mixer, TIA, HPF, VGA, and Real ADC in sequence and converted into a real digital baseband signal. The subsequent digital signal processing module can process the real digital baseband signal to obtain target parameters such as distance, speed, angle, height, and micro-motion characteristics.

[0165] Specifically, for the transmit link, the compensation unit (TXcompensation) set between TX DDFS and IQ DAC may include LO compensation unit (TX LO leakage compensation), IQ compensation unit (TX IQImbalance compensation), and HD3 compensation unit (TX HD3 compensation), etc., to implement the corresponding compensation operations for LO leakage, IQ Imbalance, and HD3 in the transmit link of the digital phase shifter architecture.

[0166] In some optional embodiments, a calibration module may be provided between the transmit link and the receive link. This calibration compensation unit can be configured to multiplex the receive link to perform calibration operations on the transmit link of the aforementioned digital phase shifter architecture. Simultaneously, the compensation unit can perform compensation operations on the transmitted signal at the transmit link end based on the parameters or coefficients obtained from the calibration operation of the calibration module. In other embodiments, a corresponding receive compensation unit may be provided simultaneously or separately in the receive link. In this case, the receive compensation unit can perform compensation on the echo signal at the receive link end based on the parameters or coefficients obtained from the aforementioned calibration operation.

[0167] like Figure 14 As shown, the aforementioned calibration module may include a BIST unit and an auxiliary circuit unit, etc. That is, the output port of the transmit link is connected to any node between RealMixer and RealADC in the receive link through the BIST unit and the auxiliary circuit unit. For example, the IQ Modulator in the transmit link generates an RF signal of (z GHz ± x MHz) based on the x MHz digital phase-shifted baseband signal and the z GHz LO signal, and outputs it to the BIST unit through the output port. The BIST unit performs a y MHz frequency offset operation on the received RF signal to obtain an analog echo signal of (z GHz ± x MHz ± y MHz). Then, the IQ De-Modulator in the auxiliary unit is used to down-frequency the signal to obtain a preset intermediate frequency signal (z GHz ± x MHz ± y MHz - z GHz = ± x MHz ± y MHz). This intermediate frequency signal is then input to a preset node in the receive link to realize the calibration operation in the transmit link.

[0168] Optionally, the auxiliary circuit unit can be an orthogonal demodulator circuit. The output of this auxiliary circuit unit can be connected to any of the following nodes in the receiving link: the node between TIA and HPF, the node between HPF and VGA, or the node between VGA and Real ADC. Furthermore, to maximize the reuse of the receiving link structure, after the output port of one transmitting link passes through the BIST unit and the auxiliary circuit unit, the I and Q branches can be connected to different transmitting links respectively, i.e., as shown below. Figure 14As shown, this involves calibrating one transmit link by multiplexing two receive links. After calibrating the transmit link, the aforementioned compensation module (TX compensation) includes the LO compensation unit (TX LOleakage compensation), IQ compensation unit (TX IQ Imbalance compensation), and / or HD3 compensation unit (TXHD3 compensation). These compensation units are used to perform compensation operations for issues such as LO leakage, IQ Imbalance, and HD3 in the transmit link of the digital phase shifter architecture, based on the parameters obtained from the calibration.

[0169] In some optional embodiments, the BIST unit described above may include a phase-angle converter and an IQ modulator connected in sequence. The auxiliary circuit unit may include an LNA, an IQ De-Modulator, and a TIA connected in sequence. The phase-angle converter receives the RF signal output from the transmit link, while one input of the IQ modulator is connected to the output of the phase-angle converter, and the other input receives a y MHz BIST-LO signal to generate a preset echo signal. The LNA amplifies the received echo signal and sends it to one input of the IQ De-Modulator, and the other input of the IQ De-Modulator receives a z GHz RX-LO signal. The two output branches of the IQ De-Modulator (i.e., the I branch and the Q branch) are connected to corresponding nodes in their respective receive links via the TIA to output the generated preset intermediate frequency signal to both receive links. This achieves calibration while simultaneously enabling a more efficient multiplexing of the receive link design.

[0170] It should be noted that, for the calibration operation in the embodiments of this application, if the transmission link transmits a swept frequency signal, in the actual calibration operation, the TX LO signal can be used as a single-tone signal for point-by-point calibration; at the same time, the TX LO signal can also be used as a swept frequency signal for large-bandwidth calibration operation, or even the swept frequency bandwidth calibration can be used to achieve the calibration operation of the swept frequency signal for the entire frequency band in one operation.

[0171] based on Figure 14 The structure shown can be further reduced to a predetermined degree by cascading at least two BIST units in the transmit link of the digital phase shifter architecture, to achieve this. Figure 15As shown, by using two BIST units connected in series, the noise caused by the above-mentioned defects can be suppressed to -50dB, thereby effectively reducing the difficulty of developing and designing related link analog devices.

[0172] In some optional embodiments, based on the transmit link of the digital phase shifter architecture described in the embodiments of this application, when performing calibration and compensation operations for IQ Imbalance, the compensation coefficient of IQ Imbalance can be obtained in the time domain based on spectrum analysis, or in the frequency domain based on the peak ratio of the spectrum.

[0173] In some optional embodiments, in order to further improve the accuracy of the IQ Imbalance compensation coefficient, the ideal compensation coefficient can be approximated by iterative calibration and compensation, or the ideal compensation coefficient can be obtained by multi-observation calibration and compensation.

[0174] For example, regarding iterative calibration and compensation, the decision to stop the iteration operation can be based on the magnitude relationship between the compensation coefficients of two consecutive calibrations, or whether the difference between the compensation coefficients of two calibrations meets a preset iteration condition. The compensation coefficient obtained when the iteration stops is then used as the final compensation coefficient for the current scenario in subsequent operations. For multi-observation calibration and compensation, after multiple (e.g., three) calibration and compensation operations, the measurement data obtained from each operation can be subjected to FFT (Fast Fourier Transform) to obtain the corresponding amplitude and phase information. The measurements can then be subtracted and normalized to obtain the relevant data, and an observation matrix can be constructed. Subsequently, the corresponding compensation coefficients can be solved in reverse based on the data obtained by inverting this observation matrix.

[0175] In some alternative embodiments, based on the same idea as the above-described method for obtaining the IQ Imbalance compensation coefficient, methods such as iterative calibration and compensation, or multiple observation calibration and compensation, can also be used to obtain the LO leakage and / or HD3 compensation coefficients.

[0176] The examples of transmitters with compensation units mentioned above discussed the problem of solving harmonic distortion in transmitters. Research has found that some harmonic distortion may originate from components in the transmitter, such as mixers, that contain nonlinear characteristics.

[0177] by Figure 16 For example, Figure 16 This is a schematic diagram of the mixer 421 in an embodiment of this application. Figure 16As shown, mixer 421 includes a voltage-to-current converter (V / I converter), a current switch, and a current-to-voltage converter (I / V converter). The voltage-to-current converter converts a received voltage signal into a current signal; the current switch is connected to the voltage-to-current converter and the second signal generator, and is used to process the current signal output by the voltage-to-current converter using a local oscillator signal; the current-to-voltage converter is connected to the current switch and is used to convert the current signal output by the current switch into a voltage signal.

[0178] In the above structure, because the voltage-to-current converter incorporates a transistor amplifier, the nonlinear characteristics of the transistor amplifier and the low frequency of the baseband signal result in harmonic signals in the output current signal of the voltage-to-current converter, corresponding to the baseband signal. For example, the harmonics (HD) caused by the third-order nonlinearity of the baseband can be simply referred to as HD3. Similarly, the harmonics caused by the fifth-order nonlinearity are called HD5. When the current switch processes the current signal output from the voltage-to-current converter, the harmonic frequencies are up-converted to the radio frequency (RF) band. Suppressing RF harmonic signals is complex and costly. If RF harmonic signals are not removed, it will affect the signal quality of radar transmission and reception, thus impacting the accuracy of radar measurements.

[0179] The compensation unit is used to input the generated cancellation signal to the signal transmission link to cancel the harmonic signals in the radio frequency signal. The compensation unit is independent of the first signal generator.

[0180] Therefore, the compensation unit may include a cancellation signal generator. The cancellation signal output by the compensation unit can suppress harmonic signals in the radio frequency signal, reduce harmonic components in the radio frequency signal, and thus improve the signal quality of the radio frequency signal output by the transmitter.

[0181] In this embodiment, for harmonic signals in the signal transmission link, the compensation unit uses feedback or, based on the characteristics of the transmitted wave, inputs a generated cancellation signal to the signal transmission link to cancel the harmonic signals in the radio frequency signal output by the signal transmission link. This cancellation signal has characteristics such as opposite phase and similar amplitude to the harmonic signals transmitted in the radio frequency transmission circuit, thereby achieving the purpose of suppressing harmonic signals.

[0182] In some examples, the compensation unit generates a compensation signal that includes cancellation based on parameters such as the phase, frequency, or amplitude of the baseband signal generated by the first signal generator, or even the path length of the LO signal.

[0183] For example, Figure 5An example of a transmitter in which a compensation unit is connected to a signal transmission link is shown. Figure 5 In the structure shown, the compensation unit is a TX compensation unit. The TX compensation unit includes a cancellation signal generator (not shown) that can generate a cancellation signal based on the characteristics of the transmitted wave. The cancellation signal generator can be exemplified as follows: Figure 6 The TX HD3 compensation unit shown is shown.

[0184] Among them, the baseband processor ( Figure 5 The baseband signal generated by the TX DDFS (or simply baseband frame) is controlled by the TX compensation unit. Based on the parameters of the quadrature digital signal, the TX compensation unit generates a quadrature compensation signal. The quadrature compensation signal and the quadrature digital signal are combined and sent to the IQ DAC to be converted into an analog baseband signal. After LPF filtering, the signal is passed to the mixer (i.e., ...). Figure 5 The IQ modulator in the circuit performs mixing to obtain an RF signal based on the mixing of the TX LO signal and the analog baseband signal. The PA amplifies the mixed signal and outputs it through the transmitting antenna. This compensation signal cancels out at least some of the harmonic signals in the RF transmitting circuit, such as the HD3 harmonic signal. Therefore, the noise in the transmitted RF signal is greatly reduced. The RF signal can be an FMCW signal.

[0185] In other examples, the compensation unit generates a compensation signal based on harmonic information received from feedback via the radio frequency transmitting circuit. See also Figure 17 , Figure 17 for Figure 5 The diagram shows the structure of the compensation unit in the transmitter. Figure 17 As shown, the compensation unit includes a data acquisition circuit and a cancellation signal generator.

[0186] The acquisition circuit is coupled to the radio frequency transmitting circuit and is used to acquire signals from the radio frequency transmitting circuit to obtain an acquired signal. The acquired signal (or sampling signal) can reflect the waveform information (also known as harmonic parameters) in the harmonic signal, such as the phase of the main frequency signal, the phase of the harmonic signal, the frequency of the harmonic signal, the frequency of the main frequency signal, the power of the harmonic signal, and the power of the main frequency signal.

[0187] It should be noted that the harmonic parameters reflected in the acquired signal are related to the information carried by the signal that the acquisition circuit can acquire. For example, if the acquisition circuit is a power acquisition circuit, then the corresponding acquired signal includes the power of the main frequency. Alternatively, if the acquisition circuit utilizes at least part of the receiver's circuitry, then the acquired signal reflects the phase of the main frequency signal, the phase of the harmonic signal, the frequency of the harmonic signal, the frequency of the main frequency signal, the power of the harmonic signal, and the power of the main frequency signal, etc.

[0188] At least one of the aforementioned harmonic parameters can be extracted using analog circuitry. For example, the power of the output main frequency signal can be obtained through a coupler and a power detector. Alternatively, the advantages of frequency domain calculations in the digital circuitry of the radar chip can be utilized to extract the harmonic parameters. For instance, by coupling an RF transmitting circuit, a signal identical to the signal transmitted at the coupling point can be acquired as a sampling signal. This sampling signal carries the main frequency signal and harmonic signals. The sampling signal is converted into a digital signal by an ADC and then processed by digital circuitry in the frequency domain to obtain more harmonic parameters.

[0189] In one implementation, the input terminal of the acquisition circuit is connected to the output terminal or signal detection terminal of the mixer. This method can detect harmonic signals generated by the voltage-to-current converter and has a simplified acquisition circuit. For example... Figure 18 , 19 In one connection configuration shown, the input terminal of the acquisition circuit is connected to the detection terminal between the voltage-to-current converter and the current switch, and is coupled to the ADC.

[0190] In another embodiment, the input terminal of the acquisition circuit is connected to the RF output terminal or the RF detection terminal of the RF transmitting circuit. The RF output terminal is, for example, the output terminal of the RF transmitting circuit. The RF detection terminal is, for example, the input or output terminal of at least one power amplifier (PA) stage in the RF transmitting circuit. This method can acquire more accurate harmonic parameters from the RF transmitting circuit, but it has a more complex circuit structure.

[0191] In some chips that include a BIST module, the acquisition circuit can obtain the acquired signal through some or all of the circuitry within the BIST module. For example, see... Figure 19 As shown, the input terminal of the acquisition circuit is coupled to the RF output terminal, and it includes a downconverter, a filter, etc., and is connected to an IQ ADC to output a digital acquisition signal. The downconverter, filter, etc., can be multiplexed from a BIST module or a receiver.

[0192] The acquired signal is input to a cancellation signal generator. The cancellation signal generator is at least one circuit within the compensation unit. This cancellation signal generator is connected to the first signal generator, ensuring that the signal received by the radio frequency transmitting circuit simultaneously includes both the baseband signal and the cancellation signal.

[0193] For example, the cancellation signal generator includes the aforementioned cancellation signal generator and digital circuitry for extracting harmonic information. The digital circuitry for extracting harmonic information can be configured independently or at least partially shared with the digital circuitry in the radar chip.

[0194] One example of a digital circuit for extracting harmonic information is the use of digital circuitry in a radar chip for processing differential frequency baseband signals to extract harmonic information such as harmonic frequency, main frequency, and main frequency power, which is then provided to a cancellation signal generator. The cancellation signal generator generates a cancellation signal based on the received parameters.

[0195] For example, a digital circuit for extracting harmonic information extracts the dominant frequency amplitude from the acquired signal and calculates the harmonic amplitude based on the difference between the preset dominant frequency amplitude and the harmonic amplitude. A cancellation signal generator then generates a harmonic compensation signal based on the calculated harmonic amplitude and other pre-configured harmonic parameters. These pre-configured harmonic parameters can be calculated based on the sweep range and phase of the dominant frequency signal to be transmitted by the radar chip.

[0196] The cancellation signal generator can be configured independently of the first signal generator, or at least partially shared. For example, the cancellation signal generated by the cancellation signal generator is input to the first signal generator, such that the baseband signal output by the first signal generator includes the cancellation signal. The cancellation signal generator may include a third harmonic generator and a fifth harmonic generator.

[0197] For example, the compensation unit further includes an adder coupled to the cancellation signal generator and the first signal generator to combine the baseband signal generated by the first signal generator and the cancellation signal generated by the cancellation signal generator. In this embodiment, the cancellation signal includes a cancellation signal Signal_HD3 generated by the third harmonic generator to cancel the third harmonic, and a cancellation signal Signal_HD5 generated by the fifth harmonic generator to cancel the fifth harmonic. The cancellation signals Signal_HD3 and Signal_HD5, along with the baseband signal generated by the first signal generator, are combined by the adder and output to the radio frequency transmission circuit.

[0198] In summary, the transmitter circuit examples provided in this application, which use a feedback method to pre-input cancellation signals into the RF transmitting circuit, can ensure that the RF signals emitted by the chip contain sufficiently low harmonic signals under different environments.

[0199] In order to effectively suppress harmonic signals according to the actual operating environment of the chip during chip use, such as considering the influence of ambient temperature on semiconductor devices, this application also provides a method for signal cancellation of harmonic signals in the transmitter using a feedback mechanism, including:

[0200] Step 10: Acquire signals in the signal transmission link to obtain acquired signals; wherein the signal transmission link is used to generate radio frequency signals for radar detection, and the radio frequency signals contain harmonic signals.

[0201] Step 20: Detect the acquired signal, generate a cancellation signal to cancel the harmonic signal, and output it to the signal transmission link.

[0202] The method provided in this application performs a signal acquisition operation on the signal transmission link to obtain the acquired signal, and uses the acquired signal to generate a cancellation signal, which is then output to the signal transmission link. This method uses the cancellation signal to suppress harmonic signals in the radio frequency signal, reduces harmonic components in the radio frequency signal, thereby improving the signal quality of the radio frequency signal output by the transmitter, and thus improving the receiver's reception performance of the radio frequency signal.

[0203] The following is in conjunction with the appendix Figures 11 to 20 For example, a transmitter and its working process:

[0204] For example, Figure 11 The image illustrates an example of using a feedback mechanism to extract harmonic information from a transmitter, enabling a compensation unit to generate a corresponding cancellation signal. Figure 11 In the structure shown, the compensation unit includes a TX HD3 compensation unit as an example. The TXHD3 compensation unit generates a compensation signal based on the waveform characteristics of the received signal. This feedback mechanism can be executed in the radar chip's calibration mode to prevent weakening of the radar chip's signal transmission power during normal detection.

[0205] The baseband processor in the transmitter (such as Figure 11 The baseband signal generated by the orthogonal digital converter (TX DDFS) is controlled by the baseband frame in the TX compensation unit. This baseband signal is then combined with the orthogonal digital cancellation signal generated by the TX compensation unit and sent to the IQ DAC to be converted into an analog baseband signal. This analog baseband signal contains an analog cancellation signal used to cancel harmonic signals in the transmit link. This analog baseband signal is then filtered by the LPF and enters the first mixer (i.e., ...). Figure 11 The first mixer uses TX LO to mix the received filtered signal to obtain an RF signal. This RF signal is coupled through the receiver and output to the TX HD3 calibration circuit in the compensation unit (e.g., the IQ modulator in the receiver). Figure 11 (TX HD3 calibration box in the image). The TX HD3 calibration circuit can be considered as a digital circuit for extracting harmonic information.

[0206] In the receiver, the LNA amplifies the signal output from the transmitter and then outputs it to the second mixer (i.e., Figure 11The IQ demodulator in the signal processing unit (ICU) obtains the demodulated signal, which is then sent to a transimpedance amplifier for amplification. After passing through an LPF and HPF, it undergoes analog-to-digital conversion via an IQ ADC before being sent to the TX HD3 calibration circuit. The TX HD3 calibration circuit extracts harmonic information from the transmitter's feedback signal and converts it into parameters required to generate the cancellation signal via an upper-level controller, providing this information to the TX HD3 compensation unit. Examples of harmonic information acquired by the TX HD3 calibration circuit include one or more of the following parameters: initial phase, start frequency, cutoff frequency, frequency change duration, and center frequency of the harmonic signal (or main frequency signal). The TX HD3 calibration unit or the upper-level controller determines the parameters used in the compensation unit to generate the cancellation signal based on the harmonic information, such as the initial phase, the frequency of the cancellation signal, and the time delay.

[0207] It should be noted that the above examples involve the cancellation of third and / or fifth harmonics, which can be determined according to the transmitter's requirements.

[0208] In some optional embodiments, based on the transmit link of the digital phase shifter architecture described in the embodiments of this application, when performing calibration and compensation operations for HD3, since the main source of HD3 generation in the active mixer is the third harmonic of the nonlinearity of the V / IConverter, it can be achieved through methods such as... Figure 18 The compensation architecture shown is based on cubic modules, or as... Figure 19 The compensation structure shown is based on a third-harmonic waveform generator.

[0209] Figure 20 This is a schematic diagram illustrating calibration compensation for a transmit link based on a digital phase shifter architecture, as described in an embodiment of this application. Figure 20 As shown, based on the technical content related to IQ Imbalance, LO leakage, and HD3 calibration compensation operations in the embodiments of this application: For IQ Imbalance compensation, it can be achieved by compensating the conjugate signal of the BB (baseband) signal to inversely cancel the image component, and this compensation method is not affected by the IQ Imbalance calibration method. For LO Leakage compensation, it can be achieved by adjusting the DC components (i.e., DC bias) of the IQ and I channels; similarly, the LO Leakage calibration method does not affect its compensation scheme. For HD3, since the third harmonic distortion of the quadrature mixer V / I converter is the main source of HD3, and harmonic distortion is affected by DC bias, when both LO Leakage and HD3 of the transmit link need calibration, HD3 calibration should be performed after LO Leakage calibration to ensure the accuracy of HD3 calibration.

[0210] Furthermore, the compensation methods of HD3, based on the digital pre-compensation architecture of the digital cube module and the digital pre-compensation architecture of the frequency multiplier waveform generator module, directly affect the subsequent calibration scheme and compensation process. Specifically:

[0211] In an optional embodiment, for a digital pre-compensation architecture based on a digital cubic module, the LO leakage can be calibrated and compensated first. Under a stable DC bias, the root cause of the HD3 problem, namely the HD3 compensation coefficient, can be calibrated. Then, the IQ Imbalance can be calibrated and compensated. After that, the third harmonic distortion can be compensated for on both the IQ and IQ paths based on the pre-compensation results of the IQ Imbalance.

[0212] In an optional embodiment, for a digital pre-compensation architecture based on a frequency multiplier waveform generator module, after calibrating and compensating for LO leakage, the compensation coefficient of HD3 can be calibrated, and IQ Imbalance can be calibrated and compensated under a stable DC bias. Subsequently, the third harmonic distortion is compensated for on both IQ channels based on the pre-compensation result of IQ Imbalance using the compensation result.

[0213] In another optional embodiment, for a digital pre-compensation architecture based on a frequency multiplier waveform generator module, after calibrating and compensating for LO leakage, the compensation coefficient of HD3 can be calibrated, and IQ Imbalance can be calibrated and compensated under a stable DC bias. Subsequently, based on the compensation results, the actual waveforms of the IQ signals and the compensation coefficient of HD3 can be calculated respectively, and the waveform information of the 3rd and 5th harmonic frequencies that need to be pre-compensated can be calculated.

[0214] In another optional embodiment, for a digital pre-compensation architecture based on a frequency harmonic waveform generator module, the LO leakage can be calibrated and compensated first. Then, the pre-compensation coefficients for HD3 and IQ Imbalance can be calibrated simultaneously through multiple (e.g., three) observations. Afterward, the pre-compensation coefficients at the HD3 mirror position can be calibrated through further observations (e.g., two). Finally, the 3rd and 5th harmonic coefficients requiring pre-compensation can be calculated using the pre-compensation coefficients at HD3 and its mirror position. It should be noted that the observations in this embodiment are used to represent testing and comparative analysis of different test results.

[0215] See Figure 20As shown in the diagram, the acquisition circuit has two acquisition branches that can be dynamically switched. One acquisition branch's input is connected between a voltage-to-current converter and a current switch; the other acquisition branch's input is connected to the output of a power amplifier, and this branch includes an IQ demodulator. Furthermore, Figure 20 In the structure shown, the acquisition circuit is also equipped with multiplexers, wherein the input terminals of the multiplexers are respectively connected to the output terminals of the two acquisition branches, and the output terminals are used to output the acquisition signals.

[0216] exist Figures 18 to 20 In the structure shown, the acquired signal can be an analog signal, that is, the output terminal of the acquisition circuit is connected to the IQ ADC; or, the acquired signal can be a digital signal, then the acquisition circuit includes at least an IQ ADC.

[0217] It should be noted that when the radio frequency signals transmitted by the signal transmission link are not orthogonal signals, then... Figures 18 to 20 The acquisition circuit can be implemented using non-orthogonal components. For example, a single-ended downconverter mixer can be used instead of an IQ decoder, and a single-ended analog-to-digital converter can be used instead of an IQ ADC.

[0218] like Figure 21 As shown, this disclosure also provides a signal transmission method applied to an electromagnetic wave device having at least one signal transmission link. The signal transmission method includes:

[0219] Step 2101: Determine the phase of the radio frequency transmission signal for each signal transmission link;

[0220] Step 2102: Determine the initial phase of the transmitting digital baseband signal in each signal transmission link based on the phase of the radio frequency transmitted signal;

[0221] Step 2103: Generate the transmitting digital baseband signal based on the determined initial phase;

[0222] Step 2104: Convert the digital baseband signal at the transmitting end into an analog baseband signal at the transmitting end, and perform a phase shift operation on the local oscillator signal at the transmitting end based on the analog baseband signal at the transmitting end.

[0223] The signal transmission method of this disclosure generates a digital baseband signal in the digital domain by using a digital phase shifter architecture, which has better orthogonality and lower sidelobes. Its phase shift phase can be generated very accurately, resulting in higher phase modulation accuracy. This realizes a vehicle radar system with high-precision digital phase shifting function, reduces the isolation requirement between antennas, and has the advantages of low link loss, low cost, no need for offline calibration. It can also support more flexible transmission schemes, such as high-performance Doppler division multiplexing and frequency division multiplexing, and can support frequency response compensation in the digital domain.

[0224] In some exemplary embodiments, the transmitting digital baseband signal is a single-tone signal and the transmitting local oscillator signal is a frequency sweep signal; or, the transmitting digital baseband signal is a frequency sweep signal and the transmitting local oscillator signal is a single-tone signal.

[0225] In some exemplary embodiments, the bandwidth of the sweep signal is above 2 GHz.

[0226] This disclosure also provides an integrated circuit that may include the signal transceiver link described above. Optionally, the integrated circuit may be a millimeter-wave radar chip (chip or die).

[0227] In some optional embodiments, the integrated circuit may be an AiP (Antenna-In-Package) chip structure, an AoP (Antenna-On-Package) chip structure, or an AoC (Antenna-On-Chip) chip structure.

[0228] According to other embodiments of this disclosure, an electromagnetic wave device is also proposed. This electromagnetic wave device may include an antenna and an integrated circuit as described above. The integrated circuit is electrically connected to the antenna and is used to transmit and receive electromagnetic wave signals. For example, the electromagnetic wave device may include: a carrier, an integrated circuit as described in any of the above embodiments, and an antenna, etc. The integrated circuit may be disposed on the carrier; the antenna may be disposed on the carrier, or integrated with the integrated circuit as a single device disposed on the carrier (i.e., the antenna may be an antenna disposed in an AiP, AoP, or AoC structure); wherein the integrated circuit is connected to the antenna (i.e., the sensing chip or integrated circuit does not integrate an antenna, such as a conventional SoC), and is used to transmit and receive electromagnetic wave signals. The carrier may be a printed circuit board (PCB).

[0229] This disclosure provides an apparatus that may include: an apparatus body; and an electromagnetic wave device as described above disposed on the apparatus body; wherein the electromagnetic wave device is used for target detection and / or communication to provide reference information to the operation of the apparatus body.

[0230] This disclosure also provides an electronic device that can be represented in the form of a general computing device. The components of the electronic device may include, but are not limited to: at least one processing unit, at least one storage unit, a bus connecting different system components (including the storage unit and the processing unit), a display unit, etc. The storage unit stores program code that can be executed by the processing unit, causing the processing unit to perform the methods described in this specification according to the various exemplary embodiments of this disclosure. The storage unit may include a readable medium in the form of volatile storage units, such as random access memory (RAM) and / or cache memory units, and may further include read-only memory (ROM).

[0231] The storage unit may also include a program / utility having a set (at least one) of program modules, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0232] A bus can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus that uses any of the various bus structures.

[0233] The electronic device can also communicate with one or more external devices (e.g., keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable a user to interact with the electronic device, and / or any device that enables the electronic device to communicate with one or more other computing devices (e.g., routers, modems, etc.). This communication can be performed via input / output (I / O) interfaces. Furthermore, the electronic device can communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter. The network adapter can communicate with other modules of the electronic device via a bus. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0234] For example, the electronic device in this embodiment may further include: a device body; and an electromagnetic wave device disposed on the device body as described in any of the above embodiments; wherein the electromagnetic wave device can be used to realize functions such as target detection and / or wireless communication.

[0235] Specifically, based on the above embodiments, in one optional embodiment of this disclosure, the electromagnetic wave device can be disposed outside the device body or inside the device body. In other optional embodiments of this disclosure, the electromagnetic wave device can be partially disposed inside the device body and partially disposed outside the device body. This disclosure does not limit the specific implementation; it can be determined according to the circumstances.

[0236] In an optional embodiment, the aforementioned device body can be a component or product applied in fields such as smart cities, smart homes, transportation, smart homes, consumer electronics, security monitoring, industrial automation, in-cabin detection (such as smart cockpits), medical devices, and healthcare. For example, the device body can be intelligent transportation equipment (such as automobiles, bicycles, motorcycles, ships, subways, trains, etc.), security equipment (such as cameras), liquid level / flow rate detection equipment, smart wearable devices (such as wristbands, glasses, etc.), smart home devices (such as robot vacuum cleaners, door locks, televisions, air conditioners, smart lights, etc.), various communication devices (such as mobile phones, tablets, etc.), as well as devices such as barriers, intelligent traffic lights, intelligent signs, traffic cameras, and various industrial robotic arms (or robots). It can also be various instruments for detecting vital signs parameters and various devices equipped with such instruments, such as in-cabin vital sign detection in automobiles, indoor personnel monitoring, smart medical devices, and consumer electronic devices.

[0237] This disclosure also provides a non-transitory computer-readable storage medium storing computer-readable instructions that, when executed by a processor, cause the processor to perform the signal transmission method described above.

[0238] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. The technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, or network device, etc.) to execute the methods described above according to the embodiments of this disclosure.

[0239] Software products may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example,, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections with one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0240] Computer-readable storage media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable storage medium may also be any readable medium other than a readable storage medium that can transmit, propagate, or transfer a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0241] Program code for performing the operations of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing devices can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0242] The aforementioned computer-readable medium carries one or more programs, which, when executed by a device, cause the computer-readable medium to perform the aforementioned functions.

[0243] Those skilled in the art will understand that the above modules can be distributed in the device as described in the embodiments, or they can be modified accordingly and placed in one or more devices that are unique to this embodiment. The modules in the above embodiments can be combined into one module, or they can be further divided into multiple sub-modules.

[0244] According to embodiments of this disclosure, a computer program is proposed, including a computer program or instructions, which, when executed by a processor, can perform the methods described above. In an optional embodiment, the integrated circuit described above can be a millimeter-wave radar chip. The types of digital functional modules in the integrated circuit can be determined according to actual needs. For example, in a millimeter-wave radar chip, the receiving baseband digital module can be used for functions such as range Vidopler transformation, velocity Vidopler transformation, constant false alarm rate detection, direction of arrival detection, point cloud processing, etc., to acquire information such as the target's range, horizontal angle, pitch angle, velocity, altitude, micro-Doppler motion characteristics, shape, size, surface roughness, and dielectric properties.

[0245] It should be noted that wireless devices can transmit and receive radio signals to achieve functions such as target detection and / or communication, thereby providing the device body with target detection information and / or communication information, and thus assisting or even controlling the operation of the device body.

[0246] For example, when the aforementioned device is applied to an advanced driver assistance system (ADAS), wireless devices (such as millimeter-wave radar) used as vehicle sensors can assist the ADAS system in realizing application scenarios such as adaptive cruise control, automatic braking assist (AEB), blind spot detection warning (BSD), lane change assist warning (LCA), rear cross traffic alert (RCTA), parking assist, rear vehicle warning, collision avoidance, and pedestrian detection.

[0247] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0248] The embodiments described above merely illustrate preferred embodiments of this disclosure and the technical principles employed. While the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. Various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of this disclosure. Therefore, although this disclosure has been described in detail through the above embodiments, it is not limited to these embodiments. Many other equivalent embodiments may be included without departing from the concept of this disclosure, and the protection scope of this patent is determined by the appended claims.

Claims

1. A signal transmission link, characterized in that, In a radar system, the signal transmission link includes: a transmitting baseband digital module, a digital-to-analog converter module, a transmitting local oscillator, and a transmitting quadrature modulator. The digital-to-analog converter module includes two identical digital-to-analog converters, wherein: The transmitting baseband digital module is configured to generate two orthogonal transmitting digital baseband signals and send the two orthogonal transmitting digital baseband signals into one of the digital-to-analog converters respectively. The transmitting digital baseband signals are single-tone signals. The digital-to-analog converter module is configured to convert the two orthogonal transmitting digital baseband signals into two transmitting analog baseband signals. The transmitting local oscillator is configured to provide a transmitting local oscillator signal, wherein the transmitting local oscillator signal is an FMCW signal in the centimeter wave band or millimeter wave band; and The transmitting quadrature modulator is configured to perform frequency shifting and phase shifting operations on the transmitting local oscillator signal based on the two transmitting analog baseband signals, so as to form a predetermined phase-shifted FMCW radio frequency transmission signal. The transmitting digital baseband signal includes preset phase information so that the predetermined phase-shifted FMCW radio frequency transmission signal is radiated into a preset spatial region via the transmitting antenna. The preset phase information is the difference between the phase of the predetermined phase-shifted FMCW radio frequency transmission signal and the phase of the transmitting local oscillator signal.

2. The signal transmission link according to claim 1, characterized in that, The bandwidth of the local oscillator signal at the transmitting end is above 2 GHz.

3. A signal transmission link, characterized in that, In a radar system, the signal transmission link includes a first signal source and a digital phase-shifting module; wherein, The first signal source is configured to generate a first analog signal, wherein the first analog signal is an FMCW signal in the centimeter-wave band or millimeter-wave band; and The digital phase-shifting module is configured to use digital quadrature modulation to phase-shift the first analog signal to form a predetermined phase-shifted FMCW radio frequency transmission signal; The digital phase-shifting module includes a second signal source, a digital-to-analog converter, and a mixer connected in sequence; wherein... The second signal source is configured to generate a first digital signal; The digital-to-analog converter module is configured to convert the first digital signal into a second analog signal; and The mixer is configured to phase-shift the first analog signal based on the second analog signal, or to shift the frequency while phase-shifting, to form the predetermined phase-shifted FMCW radio frequency transmission signal, wherein the phase of the first digital signal is the difference between the phase of the predetermined phase-shifted FMCW radio frequency transmission signal and the phase of the first analog signal.

4. The signal transmission link according to claim 3, characterized in that, The first digital signal includes two orthogonal transmitting digital baseband signals; The second signal source is a transmitting baseband digital module, and the digital-to-analog conversion module includes two identical digital-to-analog converters; The transmitting baseband digital module is configured to generate two orthogonal transmitting digital baseband signals and send the two orthogonal transmitting digital baseband signals into one of the digital-to-analog converters respectively. The digital-to-analog converter module is configured to convert the two orthogonal transmitting digital baseband signals into two transmitting analog baseband signals.

5. The signal transmission link according to any one of claims 3-4, characterized in that, The first signal source is a transmitting local oscillator, and the first analog signal is a transmitting local oscillator signal.

6. The signal transmission link according to claim 5, characterized in that, It also includes a power amplifier configured to amplify the FMCW radio frequency transmit signal.

7. The signal transmission link according to claim 6, characterized in that, It also includes a transmitting antenna, configured to radiate the power-amplified FMCW radio frequency transmission signal to a predetermined area.

8. A signal transceiver link, characterized in that, Includes a signal transmission link as described in any one of claims 1 to 7, as well as a signal reception link and a calibration link; The signal receiving link includes a receiving-end local oscillator, a receiving-end mixer, an analog-to-digital converter, and a receiving-end baseband digital module; wherein... The receiving local oscillator is configured to provide a receiving local oscillator signal; The receiving mixer is configured to perform a mixing operation on the received echo signal based on the receiving local oscillator signal to obtain a receiving analog baseband signal; the echo signal is a signal formed by the reflection and / or scattering of the signal transmitted by the signal transmission link by the target object. The analog-to-digital converter is configured to convert the receiving analog baseband signal into a receiving digital baseband signal; The receiving baseband digital module is configured to process the receiving digital baseband signal to achieve target detection and / or wireless communication. The calibration link includes an auxiliary receiving path (ARX) and a calibration receiving unit. The calibration receiving unit is configured to calibrate the ARX, and the calibrated ARX is configured to calibrate the signal transmission link.

9. The signal transceiver link according to claim 8, characterized in that, The receiving mixer is a real-number mixer, and the analog-to-digital converter is a real-number analog-to-digital converter; or... The receiving mixer is a quadrature mixer, and the analog-to-digital converter is a quadrature analog-to-digital converter.

10. The signal transceiver link according to claim 8, characterized in that, The receiving end local oscillator signal is a swept frequency signal; or, the receiving end local oscillator signal is a single-tone signal.

11. The signal transceiver link according to claim 8, characterized in that, It also includes a receiving antenna configured to receive echo signals.

12. An integrated circuit, characterized in that, This includes a signal transmission link as described in any one of claims 1 to 7, or a signal transceiver link as described in any one of claims 8 to 11.

13. The integrated circuit according to claim 12, characterized in that, The integrated circuit is a millimeter-wave chip.

14. An electromagnetic wave device, characterized in that, include: Carrier; The integrated circuit as described in any one of claims 12 to 13 is disposed on the carrier; An antenna is disposed on the carrier, or the antenna and the integrated circuit are integrated into a single device disposed on the carrier; the antenna includes a transmitting antenna and a receiving antenna. The integrated circuit is connected to the antenna and is used to transmit and / or receive electromagnetic wave signals.

15. A user terminal device, characterized in that, include: Equipment body; as well as The electromagnetic wave device as described in claim 14 is disposed on the device body; The electromagnetic wave device is used for target detection and / or wireless communication to provide reference information for the operation of the device body.

16. A signal transmission method, characterized in that, The signal transmission method, applied to a radar system having at least one signal transmission link as described in any one of claims 1 to 7, comprises: Determine the phase of the radio frequency transmitted signal for each of the aforementioned signal transmission links; The initial phase of the transmitting digital baseband signal in each of the signal transmission links is determined based on the phase of the radio frequency transmitted signal, wherein the transmitting digital baseband signal is a single-tone signal at the MHz level; The transmitting digital baseband signal is generated based on the determined initial phase; The transmitting digital baseband signal is converted into a transmitting analog baseband signal, and the transmitting local oscillator signal is phase-shifted based on the transmitting analog baseband signal. The transmitting local oscillator signal is an FMCW signal in the centimeter wave band or millimeter wave band.

17. A non-transitory computer-readable storage medium having stored computer-readable instructions thereon, which, when executed by a processor, cause the processor to perform the signal transmission method as described in claim 16.

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