Calibration circuit and method, phase shifting circuit, radio frequency transceiver circuit, radar and device

Abstract

Embodiments of the present disclosure provide a calibration circuit for a phase shifter, a calibration method, a phase shifting circuit, a radio frequency transmitting circuit, a radio frequency receiving circuit, a radar sensor and an electronic device. The calibration circuit for the phase shifter comprises a phase acquisition circuit and a phase calibration circuit, wherein the phase acquisition circuit is coupled to the phase shifter, configured to modulate a radio frequency signal output by the phase shifter by using a first baseband signal, down-convert the modulated radio frequency signal to a baseband to obtain a second baseband signal containing an actual phase; the phase calibration circuit is coupled to the phase acquisition circuit, configured to obtain the actual phase in the second baseband signal, determine a calibration phase of the phase shifter according to a phase deviation between the actual phase and a preset phase shift phase, and generate a phase shift control signal to be sent to the phase shifter according to the calibration phase. The calibration circuit of the embodiments of the present disclosure has small calibration error and high precision.

Description

Technical Field

[0001] This disclosure relates to, but is not limited to, the field of radio frequency technology, and particularly to a calibration circuit, calibration method, phase shifting circuit, radio frequency transmitting circuit, radio frequency receiving circuit, radar sensor, and electronic device for a phase shifter. Background Technology

[0002] A phase shifter is a device that adjusts the phase of a wave. Radio frequency (RF) phase shifters, which adjust the phase of RF signals, are crucial components of RF and microwave transceiver systems. Due to factors such as circuit manufacturing processes, operating temperature, and the electromagnetic environment, the accuracy of their phase adjustment can be inaccurate, necessitating calibration. Traditionally, calibration requires precise measurements of the RF phase shifter to determine the magnitude of the error. The phase shifter settings are then adjusted to meet the required accuracy, thus achieving calibration. This process typically requires additional instruments such as network analyzers and complex testing methods, which are extremely costly in the millimeter-wave and microwave frequency bands. Furthermore, the necessity of using instruments means that the measurement is highly dependent on the environment, making it impossible to perform real-world measurements and calibrations during actual use, highlighting significant limitations. Summary of the Invention

[0003] This disclosure provides a calibration circuit, calibration method, phase shifting circuit, radio frequency transmitting circuit, radio frequency receiving circuit, radar sensor, and electronic equipment for a phase shifter, achieving accurate calibration of the phase shifter without relying on measuring instruments.

[0004] On one hand, this disclosure provides a calibration circuit for a phase shifter, comprising a phase acquisition circuit and a phase calibration circuit, wherein: the phase acquisition circuit is coupled to the phase shifter and is used to modulate the radio frequency sampling signal acquired by the phase shifter using a first baseband signal, and output a second baseband signal containing the actual phase; the actual phase is the phase of the radio frequency signal output by the phase shifter; the phase calibration circuit is coupled to the phase acquisition circuit to receive the second baseband signal and is used to acquire the actual phase in the second baseband signal, determine and store calibration phase information based on the phase deviation between the actual phase and a preset phase shift phase, so as to generate a phase shift control signal to be sent to the phase shifter based on the calibration phase.

[0005] On the other hand, embodiments of this disclosure also provide a phase shifting circuit, which includes a phase shifting controller, a phase shifter, and a calibration circuit as described in the first aspect, wherein: the phase shifting controller is coupled to the calibration circuit and the phase shifter, and receives a phase shifting command, and is used to output a phase shifting control signal according to the phase shifting phase in the phase shifting command and the corresponding stored calibration phase information; the phase shifter is used to perform phase shifting processing on the radio frequency signal according to the phase shifting control signal.

[0006] On the other hand, this disclosure also provides a radio frequency transmitting circuit, including a local oscillator circuit, a phase shifting circuit as described in the above example, and a transmitting antenna system. The local oscillator circuit outputs the generated radio frequency transmitting signal to the phase shifting circuit, and the phase shifting circuit shifts the phase of the radio frequency transmitting signal and inputs it into the transmitting antenna system to convert it into electromagnetic waves for radiation.

[0007] On the other hand, this disclosure also provides a radio frequency receiving circuit, which includes a receiving antenna system, a phase shifting circuit as described in the above example, a local oscillator circuit, and a mixer. The receiving antenna system converts electromagnetic waves into radio frequency receiving signals and outputs them to the phase shifting circuit. The phase-shifted radio frequency receiving signal and the local oscillator signal output by the local oscillator circuit are input to the mixer to output a down-converted difference frequency signal.

[0008] On the other hand, embodiments of this disclosure also provide a radar sensor, which includes a radio frequency transmitting circuit as described in the above examples, and / or a radio frequency receiving circuit as described in the above examples.

[0009] In another aspect, embodiments of this disclosure also provide an electronic device, which includes at least one of the phase-shifting circuit, the radio frequency transmitting circuit, the radio frequency receiving circuit, and the radar sensor described in the above examples.

[0010] In another aspect, embodiments of this disclosure also provide a calibration method for a phase shifter, comprising: acquiring a radio frequency signal with an actual phase output by the phase shifter; modulating the radio frequency signal using a first baseband signal; downconverting the modulated radio frequency signal to baseband to obtain a second baseband signal containing the actual phase; acquiring the actual phase in the second baseband signal; determining the calibration phase of the phase shifter based on the phase deviation between the actual phase and a preset phase shift phase; and sending a phase shift control signal to the phase shifter based on the calibration phase.

[0011] The calibration circuit for a phase shifter according to the present disclosure converts the actual phase carried by the radio frequency signal into a phase carried by the second baseband signal at the intermediate frequency, and extracts phase information from the radio frequency acquisition signal in the low frequency band using the first baseband signal. Thus, the extracted phase information can be compared with a preset phase shift phase (i.e., target phase) to obtain the detection results of whether the phase shifter's phase shift of the signal meets expectations and the phase deviation. If it does not meet expectations, multiple calibrations can be used to form progressively accurate feedback, which can make the phase shifter's phase shift control of the signal more accurate and achieve precise calibration of the phase shifter.

[0012] Other features and advantages of this disclosure will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the disclosure. Other advantages of this disclosure may be realized and obtained by means of the embodiments described in the description, claims, and drawings. Attached Figure Description

[0013] The accompanying drawings are provided to 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.

[0014] Figure 1 A schematic diagram of a calibration circuit provided in an embodiment of this disclosure;

[0015] Figure 2 This is a schematic diagram of another calibration circuit provided in an embodiment of the present disclosure;

[0016] Figure 3 A schematic diagram of another calibration circuit provided in an embodiment of this disclosure;

[0017] Figure 4 A schematic diagram of another calibration circuit provided in an embodiment of this disclosure;

[0018] Figure 5 A schematic diagram of another calibration circuit provided in an embodiment of this disclosure;

[0019] Figure 6 A schematic diagram of another calibration circuit provided in an embodiment of this disclosure;

[0020] Figure 7 A schematic diagram of a phase calibration circuit provided in an embodiment of this disclosure;

[0021] Figure 8 A schematic diagram of a radio frequency transmitting circuit provided in an embodiment of this disclosure;

[0022] Figure 9A schematic diagram of a radio frequency receiving circuit provided in an embodiment of this disclosure;

[0023] Figure 10 A schematic diagram of another radio frequency transmitting circuit provided in an embodiment of this disclosure;

[0024] Figure 11 A schematic diagram of another radio frequency receiving circuit provided in an embodiment of this disclosure;

[0025] Figure 12 A schematic diagram of another radio frequency transmitting circuit provided in an embodiment of this disclosure;

[0026] Figure 13 A flowchart of a calibration method for a phase shifter provided in an embodiment of this disclosure;

[0027] Figure 14 This is a schematic diagram of the phase-shifting circuit provided in an embodiment of the present disclosure. Detailed Implementation

[0028] This disclosure describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0029] This disclosure includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this disclosure may also be combined with any conventional features or elements to form a unique inventive scheme as defined by the claims. Any feature or element of any embodiment may also be combined with features or elements from other inventive schemes to form another unique inventive scheme as defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in this disclosure may be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes may be made within the scope of the appended claims.

[0030] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that the method or process does not depend on the specific order of steps described herein. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims relating to the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments disclosed herein.

[0031] In this disclosure, the term "coupled" or "coupled" can have several different meanings depending on the context in which it is used. For example, the term "coupled" can mean mechanical coupling or electrical coupling. As used herein, the term "coupled" or "coupled" can mean that two elements or devices can be directly connected to each other or connected to each other via one or more intermediate elements or devices through electrical elements, electrical signals, or mechanical elements (e.g., but not limited to, wires or cables, depending on the specific application). Examples of coupling described herein include direct electrical connections, inductive connections, or optocoupler connections. For example, an electrical connection between two electrical devices is achieved using connection methods used in semiconductor manufacturing processes. Another example is a signal connection between two electrical devices achieved using non-contact connection methods such as optocoupler components or inductive components. Yet another example is an electrical or signal connection between two electrical devices facilitated by connection methods between chip pins and slots.

[0032] Taking radar sensors as an example, configuring a phase shifter in a radar sensor can enable phased radiation without changing the hardware circuit configuration such as the antenna, and can also effectively reduce interference between radars.

[0033] In embodiments of this disclosure, the phase shifter is a circuit that adjusts the phase of a radio frequency (RF) signal using adjustable electrical parameters of a received phase-shift control signal. Examples of these adjustable electrical parameters include the voltage, duty cycle, or current of the control signal. In some examples, the phase shifter can be a quadrature phase shifter, which adaptively adjusts the phase of the RF signal by utilizing amplitude changes of quadrature signals in a quadrature circuit to output a phased RF signal. In still other examples, the phase shifter can be a transmission line phase shifter, comprising at least one set of phase-shifting units. Each phase-shifting unit includes a transmission line phase-shifting unit, a capacitor circuit, and an adjustable circuit. The transmission line phase-shifting unit includes a transmission line for transmitting the RF signal and may also include a reference ground line. The transmission line phase-shifting unit adjusts the phase of the transmitted RF signal by utilizing changes in the spacing between transmission lines, or between a transmission line and a reference ground, and / or changes in capacitance. For example, the transmission line phase-shifting unit includes a single-ended transmission line and two sets of reference ground lines, wherein different sets of reference ground lines have a spacing between them. For example, a transmission line phase-shifting unit comprises two sets of differential transmission lines, wherein there is a line spacing between the differential transmission lines of different sets of the two sets. The line spacing is used to form that the transmission line phase-shifting unit has at least two phase-shifting states. A capacitor circuit is connected between the transmission lines in one of the phase states to achieve impedance matching when switching between different phase states. The adjustable circuit is used to controllably adjust the transmission line phase-shifting unit and / or the capacitor circuit to select one of the phase states and output an RF signal of the actual phase corresponding to the phase-shifting state. The adjustable circuit is, for example, a circuit formed by at least one or more combinations of an adjustable resistor circuit, an adjustable capacitor circuit, or a MOSFET, which is controlled by the adjustable electrical parameters of the aforementioned control signal.

[0034] In actual operation, the phase shifter described above suffers from phase error due to factors such as device design, manufacturing, and operating environment. This phase error affects the accuracy of the measured physical quantities in subsequent signal processing by the radar sensor. Therefore, the radar sensor incorporates a calibration circuit for the phase shifter. When a phase shift control signal is received, the phase shifter uses the calibration circuit to compensate for the phase deviation of the corresponding phase shift, thereby outputting an radio frequency signal that best matches the preset phase shift phase in the phase shift control signal.

[0035] Figure 1The calibration circuit 20 for a phase shifter 10 provided in this embodiment includes a phase acquisition circuit 21 and a phase calibration circuit 22. The phase acquisition circuit 21 is coupled to the phase shifter 10 and is used to acquire the radio frequency (RF) signal output by the phase shifter 10. It modulates the RF sampling signal acquired by the phase shifter 10 using a first baseband signal, and downconverts the resulting modulated signal to baseband (as shown in the figure, the RF signal can be downconverted using a local oscillator signal) to obtain a second baseband signal containing the actual phase. The frequency of the second baseband signal is determined based on the frequency of the first baseband signal, and the actual phase is the phase of the RF signal output by the phase shifter. The phase calibration circuit 22 is coupled to the phase acquisition circuit 21 to receive the second baseband signal. It is used to extract the actual phase from the second baseband signal, determine and store calibration phase information based on the phase deviation between the actual phase and a preset phase shift phase, so as to generate a phase shift control signal to be sent to the phase shifter based on the calibration phase.

[0036] The first baseband signal is an intermediate frequency (IF) or low frequency (LFM) signal with a preset initial phase. This preset initial phase can be configured by pre-storing it in a memory (or using external instructions); it is obtained by synchronously sending the first baseband signal to a phase calibration circuit, where the phase calibration circuit detects it. For example, the preset initial phase of the first baseband signal is between 0° and 180° (inclusive of at least one endpoint). Using a signal modulation method, the first baseband signal adjusts its phase parameters based on the actual phase of the RF sampling signal, so that the modulated signal obtained after modulation carries the actual phase of the RF sampling signal.

[0037] The local oscillator signal is the radio frequency (RF) signal input to the phase shifter, typically an RF signal with a fixed phase (e.g., 0° phase). The phase shifter shifts the local oscillator signal to output the RF signal with the actual phase. The local oscillator signal is used to down-convert the modulation signal to obtain a second baseband signal containing the actual phase. The phase of the second baseband signal is the actual phase obtained after phase shifting by the phase shifter, or the sum (or difference) of the actual phase and a preset initial phase. By using a preset phase-shifted phase to detect the phase of the second baseband signal, the phase deviation between the obtained actual phase and the preset phase-shifted phase can be determined, and calibration phase information corresponding to the preset phase-shifted phase can be generated. The calibration phase information can be described as the phase deviation and the corresponding phase-shifted phase; the phase value of the preset phase-shifted phase after phase deviation compensation; or the unit phase deviation corresponding to a unit phase shift step calculated according to the calibration relationship between the phase deviation and the preset phase-shifted phase.

[0038] When the controller in the radar sensor generates a phase-shift command containing the phase-shift phase according to the phased array mode, the phase shifter (or calibration circuit) generates a phase-shift control signal that conforms to the phase-shift phase based on the calibration phase information. When the phase shifter receives the phase-shift control signal, it adjusts the adjustable circuit in the phase shifter according to the phase-shift control signal to achieve accurate phase shifting. The phase-shift control signal may be, for example, a pulse width or voltage amplitude describing the calibrated phase-shift phase, so that the phase offset of the radio frequency signal output by the phase shifter conforms to the phase-shift phase of the phase-shift command.

[0039] In one exemplary embodiment, the phase acquisition circuit is a circuit that acquires phase information contained in a radio frequency signal. For example... Figure 2 As shown, the phase acquisition circuit includes: an radio frequency acquisition circuit 211, a modulation circuit 212, and a frequency conversion circuit 213. The first baseband signal can be provided by an external circuit, or by... Figure 2 The baseband signal is generated by the baseband signal generation circuit 214 shown. Specifically: an RF acquisition circuit 211 is coupled to the phase shifter 10 and is used to acquire the RF signal output by the phase shifter 10 to output an RF sampling signal; a modulation circuit 212 is coupled to the RF acquisition circuit 211 and the baseband signal generation circuit 214 (optional), and is used to modulate the RF sampling signal using the first baseband signal to generate a modulated signal containing the actual phase; a frequency conversion circuit 213 is coupled to the modulation circuit 212 and the local oscillator circuit 30 (optional, in other embodiments, the local oscillator signal can be provided by an external circuit), and is used to down-convert the modulated signal using the local oscillator signal to generate a second baseband signal containing the actual phase; the baseband signal generation circuit 214 is coupled to the modulation circuit 212 and is used to generate the first baseband signal.

[0040] In this embodiment, a modulation method is employed that mixes the phase-shifted radio frequency (RF) signal with the first baseband signal. This results in the mixed RF signal carrying the phase information from the original RF signal. Subtraction mixing (down-conversion) is then used to obtain a second baseband signal with phase information. This achieves the purpose of transferring the phase information carried in the RF acquisition signal to the baseband signal, allowing for the extraction of the phase information using a lower-frequency baseband signal. Compared to using a single-ended second baseband signal for phase extraction, using orthogonal second baseband signals results in a smaller phase error.

[0041] A radio frequency (RF) acquisition circuit is a circuit that acquires radio frequency (RF) signals. In some examples, the RF acquisition circuit is electrically connected to the output of a phase shifter. For example, the RF acquisition circuit includes a coupler for outputting a single RF signal or a coupler for outputting quadrature RF signals. In other examples, the RF acquisition circuit acquires RF signals through inductive coupling. For example, the RF acquisition circuit includes a coupling line and an impedance matching circuit.

[0042] The modulation circuit is a circuit that modulates a radio frequency (RF) sampling signal. In this example, the modulation method is, for example, analog linear modulation, which achieves frequency modulation. Specifically, the first baseband signal is modulated onto the RF sampling signal through frequency modulation processing. The modulation circuit includes, for example, a mixer, such as a quadrature mixer or a mixer (single-input single-output).

[0043] The frequency conversion circuit is a single-sideband mixer circuit. In this example, frequency conversion is used to modulate (down-convert) the radio frequency signal to a baseband signal (low-frequency signal). The frequency conversion circuit can be implemented using a quadrature mixer or a single-ended mixer. After down-conversion, the output second baseband signal becomes a low-frequency signal containing the actual phase information of the radio frequency signal, which facilitates the phase calibration circuit in extracting the phase information.

[0044] A baseband signal generation circuit is a circuit used to generate a first baseband signal. It can be an external baseband circuit or integrated into an RF chip along with a phase shifter and calibration circuit. The calibration circuit is connected to the baseband signal generation circuit, either internally or externally, to receive the first baseband signal.

[0045] In an exemplary embodiment, the radio frequency acquisition circuit 211 can be a first quadrature coupler, which includes a non-inverting output terminal (or first output terminal) for outputting an in-phase radio frequency sampling signal and a quadrature output terminal (or second output terminal) for outputting a quadrature radio frequency sampling signal. Correspondingly, the first baseband signal is a quadrature signal, including an in-phase first baseband signal and a quadrature first baseband signal. The modulation circuit 212 includes two modulators, each individually connected to one output terminal of the first quadrature coupler. The modulation signal output by the modulation circuit is also a quadrature signal. The first modulator is connected to the in-phase output terminal of the first quadrature coupler, and the second modulator is connected to the quadrature output terminal of the first quadrature coupler. The first modulator is used to modulate the in-phase radio frequency sampling signal using the in-phase first baseband signal; the second modulator is used to modulate the quadrature radio frequency sampling signal using the quadrature first baseband signal. For example, as... Figure 3As shown, a first quadrature coupler 211 is coupled to the phase shifter 10 and is used to acquire the radio frequency signal output by the phase shifter 10, outputting a differential radio frequency sampling signal with a 90-degree phase difference, namely, an in-phase radio frequency sampling signal and a quadrature radio frequency sampling signal. Modulator 2121 is a first mixer for processing in-phase signals; modulator 2122 is a first mixer for processing quadrature signals. Baseband signal generation circuit 214 is coupled to the first mixer 2121 and is used to output an in-phase first baseband signal to the first mixer 2121, and is coupled to the first mixer 2122 and is used to output a quadrature first baseband signal to the first mixer 2122. The first mixer 2121 modulates the in-phase RF sampling signal and the in-phase first baseband signal to generate an in-phase modulated signal containing the actual phase. The first mixer 2122 modulates the quadrature RF sampling signal and the quadrature first baseband signal to generate a quadrature modulated signal containing the actual quadrature phase. These are the in-phase modulated signal and the quadrature modulated signal. The phase difference between the actual quadrature phase and the actual phase is 90°.

[0046] The frequency conversion circuit includes a second mixer for implementing down-conversion. This second mixer receives a modulation signal and a local oscillator signal to perform down-conversion operation using the modulation signal and the local oscillator signal, and outputs a second baseband signal. Figure 3 In the example shown, the frequency converter circuit 213 uses the local oscillator signal to down-convert the quadrature modulation signals to obtain quadrature second baseband signals. For example, the frequency converter circuit 213 includes two second mixers (not shown), which use the same local oscillator signal to down-convert the in-phase modulation signal and the quadrature modulation signal separately to obtain quadrature second baseband signals, namely, the in-phase second baseband signal and the quadrature second baseband signal. The quadrature second baseband signals both carry the actual phase of the RF acquisition signal, and the phase difference between the in-phase second baseband signal and the quadrature second baseband signal is 90°.

[0047] Optionally, each signal transmission path in the phase acquisition circuit may further include a first amplifier for amplification. Exemplarily, this first amplifier may be coupled between the modulation circuit and the frequency conversion circuit. For example, the first amplifier may be coupled between the first mixer (2121, 2122) and the frequency conversion circuit 213 to amplify the modulation signal (e.g., in-phase modulation signal and quadrature modulation signal) output from the modulation circuit (e.g., the first mixer) before inputting it into the frequency conversion circuit 213. Figure 4 As shown, when the first amplifier 215 is included, the first amplifier 215 is located on the two transmission paths used for transmitting quadrature signals.

[0048] In yet another exemplary embodiment, the radio frequency acquisition circuit includes a single-ended coupler 211', and the modulation circuit includes a single-ended third mixer 212', as shown below. Figure 5 As shown, the single-ended coupler 211' is coupled to the phase shifter 10 and is used to acquire the radio frequency signal output by the phase shifter 10; the baseband signal generation circuit 214' is coupled to the third mixer 212' and is used to output a first baseband signal to the third mixer 212'; the third mixer 212' is coupled to the single-ended coupler 211' and the baseband signal generation circuit 214' and is used to modulate the radio frequency sampling signal and the first baseband signal to generate a modulated signal containing the actual phase. This modulated signal is a single-ended signal.

[0049] Taking a single-ended modulation signal as an example, such as Figure 6 As shown, the frequency converter circuit 213' includes a second quadrature coupler 2133 and a fourth mixer (2131, 2132). The second quadrature coupler 2133 is coupled to the local oscillator circuit 30 and is used to acquire the local oscillator signal output by the local oscillator circuit 30, outputting an in-phase local oscillator signal and a quadrature local oscillator signal with a 90-degree phase difference. It includes an in-phase output terminal for outputting the in-phase local oscillator signal and a quadrature output terminal for outputting the quadrature local oscillator signal. The fourth mixer 2131 is coupled to the in-phase output terminal of the second quadrature coupler 2133 and the third mixer 212. Between the second quadrature coupler 2133 and the third mixer 212', a fourth mixer 2132 is coupled between the quadrature output terminal of the second quadrature coupler 2133 and the third mixer 212'. It is used to down-convert the single-ended modulated signal output by the third mixer 212' using the quadrature local oscillator signal output by the second quadrature coupler 2133 to generate a quadrature second baseband signal containing the actual phase. Here, the second baseband signal is an orthogonal signal containing the actual phase, including both an in-phase second baseband signal and a quadrature second baseband signal.

[0050] In other examples, the modulation circuit 212 may also include a quadrature circuit (not shown) to convert the single-ended modulation signal output by the third mixer 212' into a quadrature signal, thus enabling the modulation circuit to output both in-phase and quadrature modulation signals. In this way, using... Figure 3 Alternatively, the frequency converter circuit in example 4 can output a quadrature second baseband signal.

[0051] Optionally, in Figure 5 or Figure 6 Based on the illustrated embodiment, the phase acquisition circuit may further include a second amplifier (not shown), in Figure 5 In the example shown, the second amplifier can be coupled between the third mixer 212' and the frequency converter 213', and is used to amplify and split the modulation signal output from the third mixer 212' before outputting it. Figure 6In the example shown, the second amplifier can be coupled to a transmission path for transmitting single-ended signals between the third mixer 212' and the fourth mixer (2131, 2132). The second amplifier amplifies and quadratures the modulation signal output by the third mixer 212' and outputs it to the fourth mixer 2131 and the fourth mixer 2132 respectively.

[0052] After obtaining the second baseband signal, the actual phase carried in the second baseband signal is extracted using a phase calibration circuit. Based on the phase deviation between the actual phase and a preset phase-shifting phase, calibration phase information is determined and stored. This calibration phase is then used to generate a phase-shifting control signal to be sent to the phase shifter. The preset phase-shifting phase is set based on the actual phase to be calibrated.

[0053] In a calibration operation, the phase calibration circuit extracts the actual phase from the second baseband signal. This actual phase is obtained by phase-shifting the RF signal before calibration using the phase shifter. When the phase calibration circuit determines the phase deviation between the preset phase shift phase and the actual phase, it obtains the calibration phase information corresponding to that phase shift phase. Therefore, this calibration phase information is used to ensure that the actual phase of the RF signal output by the calibrated phase shifter in an uncalibrated state (such as the operating state) is closer to the preset phase shift phase than before calibration. Examples of this include the determined phase deviation or compensation information determined based on the phase deviation.

[0054] Here, the compensation information is determined based on the type of phase shifter, a calibration strategy set after multiple tests of the phase shifter, etc. This calibration strategy includes, but is not limited to, at least one of the following: phase shift changes of the phase shifter in different phase intervals, the effect of temperature on the phase shifter, and systematic errors of the phase shifter. Examples of phase shifter types include IQ quadrature phase shifters, transmission line phase shifters, and switching phase shifters. Examples of compensation information include: determining compensation electrical parameters for the corresponding phase shift phase based on the determined phase deviation. Compensation electrical parameters include compensation voltage, compensation duty cycle, or compensation current. For example, the phase shifter's calibration circuit calculates and stores the corresponding compensation information according to a preset minimum phase shift phase, unit phase shift phase, or maximum phase shift phase. Examples of compensation information also include: determining any other phase shift phase between any two phase shift phases and the corresponding other compensation electrical parameters (or other phase deviations) based on any two phase shift phases and the two phase deviations detected by the calibration circuit. Taking a phase shifter consisting of N cascaded transmission line phase shifters, where each transmission line phase shifter provides a phase shift of Φ°, as an example, the phase deviation corresponding to a 0° phase shift is detected by the calibration circuit. And the phase deviation corresponding to the (NΦ)° phase shift is The phase deviation of the phase shifted phase of each transmission line phase shifter can be equally divided into the total phase deviation. Right now Thus, according to To determine the compensation information for each transmission line phase shifter.

[0055] In an exemplary embodiment, such as Figure 7 As shown, the phase calibration circuit 22 uses digital signal processing to extract the actual phase to be calibrated. For this purpose, the phase calibration circuit 22 includes an ADC (analog-to-digital converter 221) and a digital signal processor 222.

[0056] The ADC 221 is coupled to the phase acquisition circuit 20 and is used to perform analog-to-digital conversion on the second baseband signal and output the corresponding second baseband digital signal.

[0057] Digital signal processor 222 is coupled to ADC 221 and is used to determine the phase deviation of the phase shifter by detecting the phase difference between a preset phase shift phase and the actual phase in the second baseband digital signal; and to store the phase deviation or compensation information determined based on the phase deviation as the calibration phase information for generating the phase shift control signal.

[0058] Here, the digital signal processor determines the phase difference by extracting the actual phase from the second baseband digital signal in the time or frequency domain. For example, the digital signal processor transforms the second baseband digital signal from a time-amplitude coordinate system to a phase-frequency coordinate system to obtain the actual phase expressed in amplitude. The phase difference between the preset phase-shifted phase and the actual phase is then calculated.

[0059] In the example where the initial phase of the first baseband signal is 0°, the digital signal processor directly obtains the actual phase using time-domain to frequency-domain conversion.

[0060] In examples where the initial phase of the first baseband signal is not 0°, the digital signal processor (ADC) uses time-domain to frequency-domain conversion to obtain a phase value including the initial phase and the actual phase, and extracts the actual phase using the initial phase of the first baseband signal through signal demodulation. Therefore, in some examples, the initial phase of the first baseband signal can be preset in the ADC for use during demodulation. In other examples, the ADC is further configured to receive the first baseband signal, perform analog-to-digital conversion on the first baseband signal, and output a corresponding first baseband digital signal; the ADC is configured to extract the actual phase by detecting the phase difference between the first baseband digital signal and the second baseband digital signal. Here, the ADC may include two analog-to-digital conversion circuits to digitize the first baseband signal and the second baseband signal respectively; and the ADC uses digital signal demodulation to demodulate the first baseband digital signal and the second baseband digital signal to obtain the actual phase; calculates the phase difference between the actual phase and a preset phase-shifted phase; and obtains and stores calibration phase information using at least one phase difference obtained from at least one calibration.

[0061] In the example where the second baseband signal is an orthogonal signal, the phase calibration circuit performs individual phase difference calculations for each path of the second baseband signal. By utilizing the characteristic that each path's phase difference has a 90° phase difference with the orthogonal signal, the error caused by the initial phase of the local oscillator signal in the phase difference can be removed in a single calibration, thereby improving the calibration accuracy.

[0062] In such Figure 4 or Figure 6 In the embodiment shown, when the second baseband signal output by the phase acquisition circuit includes an in-phase second baseband signal and a quadrature second baseband signal, the digital signal processor 222 obtains the actual phase in the second baseband signal in the following manner: it obtains the first actual phase in the in-phase second baseband signal and the second actual phase in the quadrature second baseband signal, and takes the average of the first actual phase and the second actual phase to obtain the final actual phase.

[0063] The calibration phase information obtained using any of the above examples is used by the phase shifting circuit containing the phase shifter so that, upon receiving a phase shift command, the phase shifter can be controlled to convert the phase of the received radio frequency signal to the calibrated actual phase. The calibrated actual phase is closer to the phase shift phase set in the phase shift command.

[0064] The phase-shifting circuit includes a calibration circuit as described in any of the examples above, a phase-shifting controller, and a phase shifter. The phase-shifting controller may be integrated into a digital signal processor within the calibration circuit, or it may be a separate circuit connected to the digital signal processor. Figure 14As shown, this embodiment of the disclosure also provides a phase-shifting circuit including a phase shifter 10, a calibration circuit 20, and a phase-shifting controller 40. The calibration circuit 20 is coupled to the phase shifter 10 and is used to perform phase calibration operations on the phase shifter 10 as provided in any of the examples above during calibration state ①. The phase-shifting controller 40 is coupled to the calibration circuit 20 and the phase shifter 10, and receives a phase-shifting command during operating state ②. It is used to output a phase-shifting control signal to the phase shifter 10 according to the phase-shifting phase in the phase-shifting command and its corresponding stored calibration phase information. The phase shifter 10 is used to perform phase-shifting processing on the radio frequency signal according to the phase-shifting control signal.

[0065] The phase shift controller 40 can be shared with the digital signal processor in the calibration circuit, or it can be configured separately and share the same storage area with the digital signal processor. Taking the phase shift circuit integrated into a radar sensor as an example, the phase shift strategy configured by the radar sensor generates a phase shift command, which contains the phase shift phase to be executed by the phase shift circuit. The phase shift controller extracts the calibration phase information corresponding to the phase shift phase in the corresponding phase shift command through interaction with the memory, and converts it into a phase shift control signal that can be recognized by the phase shifter, such as a voltage signal, current signal, or PWM signal. This phase shift control signal is intended to control the adjustable circuit in the phase shifter 10 to adjust the phase of the radio frequency signal received by the phase shifter to a phase shift phase, thereby reducing the phase shift deviation of the phase shifter caused by factors such as external environment, operating voltage, and manufacturing process.

[0066] In an exemplary embodiment, this disclosure also provides a radio frequency (RF) transmitting circuit, or RF transmitting system, comprising a local oscillator circuit, a phase-shifting circuit of any of the foregoing embodiments, and a transmitting antenna system. The local oscillator circuit shifts the generated RF signal through the phase-shifting circuit and then inputs it into the transmitting antenna system to convert it into electromagnetic waves for radiation. Specifically, in calibration mode, the local oscillator circuit generates an RF signal and sends it to the phase-shifting circuit. After phase shifting, the phase-shifting circuit transmits the electromagnetic wave signal through the transmitting antenna system. During this process, the calibration circuit in the phase-shifting circuit can perform at least one calibration operation on the phase shifter. For example, at time i, the calibration circuit obtains the RF signal output by the phase shifter corresponding to a preset phase-shifting phase θi, obtains the phase difference Δθi between the actual phase θ'i and the phase-shifting phase θi using any of the aforementioned methods, and thereby stores the corresponding calibration phase information. According to the calibration strategy, the calibration circuit re-executes the calibration operation at different times (such as time i+1, time i+2, etc.) using different phase shift phases θ(i+1), θ(i+2), etc., so as to determine the calibration phase information corresponding to any phase shift phase by using the different phase differences obtained, or to determine the calibration phase information corresponding to the phase shift phase obtained based on different phase shift steps.

[0067] In operation, the phase shift controller reads the corresponding calibration phase information according to the received phase shift command and generates a phase shift control signal, which is fed back to the phase shifter. The phase shifter outputs a calibrated phase-shifted radio frequency signal so that the phase shift phase of the output radio frequency signal conforms to the preset phase shift phase set by the phase shift command.

[0068] In a radio frequency (RF) transmitting circuit, the RF signal output from the phase-shifting circuit is sent to the transmitting antenna system. The transmitting antenna system converts the RF signal provided by the signal transmitter (such as a local oscillator circuit) into electromagnetic waves radiated into free space through electromagnetic conversion. To achieve this electromagnetic conversion, the transmitting antenna system includes a radiating section and a feeding section. The radiating section is typically implemented in a patterned form on a metal layer of an integrated circuit. Examples of the radiating section include patch-based radiating structures or slotted radiating structures. The feeding section is coupled between the signal transmitter and the radiating section and is used to transmit changing electrical signals. For example, the feeding section transmits the changing electrical signal output from a signal generator to the radiating section, enabling the radiating section to generate electromagnetic waves using the RF transmitted signal.

[0069] By using a phase shifter, the radio frequency transmitting circuit can change the radiation direction of the antenna without adjusting the structure of the transmitting antenna system, thereby achieving phase control and reducing radar interference.

[0070] In an exemplary embodiment, this disclosure also provides a radio frequency (RF) receiving circuit, including a receiving antenna system, a phase-shifting circuit of any of the foregoing embodiments, a local oscillator circuit, and a mixer. The receiving antenna system converts electromagnetic waves into an RF received signal (or RF signal). The RF received signal is phase-shifted by the phase-shifting circuit and then input to the mixer along with the local oscillator signal output by the local oscillator circuit to output a difference frequency signal after down-conversion. In calibration mode, the phase-shifting circuit in the RF receiving circuit undergoes the same or similar calibration process as the phase-shifting circuit in the RF transmitting circuit. In operating mode, the phase-shifting circuit in the RF receiving circuit operates in the same or similar manner as the phase-shifting circuit in the RF transmitting circuit.

[0071] In a radio frequency (RF) receiving circuit, similar in structure to the transmitting antenna system in an RF transmitting circuit, the receiving antenna system converts electromagnetic waves of a specific frequency band in free space into RF received signals. Unlike the aforementioned RF transmitting circuit, in an RF receiving circuit, the receiving antenna system outputs the RF received signal to a phase-shifting circuit. Taking a radar sensor containing an RF receiving circuit as an example, by using a phase shifter, the RF receiving circuit can change the detection direction of the receiving antenna without adjusting the structure of the receiving antenna system, thereby achieving phase control and reducing radar interference.

[0072] The following examples illustrate specific implementations of radio frequency (RF) transmitting and receiving circuits that include phase-shifting circuits.

[0073] like Figure 8 The diagram illustrates a radio frequency (RF) transmitting circuit according to an embodiment of this disclosure. This RF transmitting circuit includes a local oscillator circuit 401, a phase-shifting circuit (including a phase shifter 402 and a calibration circuit), a driver amplifier 404, and a transmitting antenna system. The calibration circuit is shown within the dashed line in the diagram. In this example, the calibration circuit includes a quadrature coupler 403 (i.e., the aforementioned RF acquisition circuit), a quadrature mixer 405 (i.e., the aforementioned modulation circuit), an amplifier 406, a mixer 407 (i.e., the aforementioned frequency conversion circuit), and a baseband generation and processing circuit 408 (a combination of the aforementioned baseband signal generation circuit and phase calibration circuit). The quadrature coupler 403 couples the output signal of the phase shifter 402 at a certain ratio, ensuring that the coupled signal is large enough to accurately reflect the output performance of the phase shifter 402, while avoiding extracting an excessively large signal that could affect the operation of the power amplifier. In this example, the output of the quadrature coupler 403 is a pair of RF signals, or RF acquisition signals, with a 90-degree phase difference (i.e., I in the diagram). RF and Q RF (This is a high-frequency signal); the baseband generation and processing circuit 408 generates a first baseband signal (i.e., I in the figure) for providing calibration. IF and Q IF The frequency of the first baseband signal can range from tens of kHz to hundreds of MHz. Since the first baseband signal is a low-frequency signal, it is easy to process (e.g., extract phase). The first baseband signal generated by the baseband generation and processing circuit 408 is mixed with the radio frequency signal output from the quadrature coupler 403 in the quadrature mixer 405 (I... RF -I IF or I RF +I IF Q RF -Q IF Or Q RF +Q IF This generates two signals with single-sideband characteristics, i.e., the aforementioned modulation signals. These are amplified by amplifier 406 and then fed into mixer 407. Mixer 407 also receives the local oscillator signal from local oscillator circuit 401. Mixer 407 performs down-conversion processing, outputting two second baseband signals Vout. The down-conversion processing then synchronizes these Vout signals with I... IF and Q IFWhile having the same frequency, it contains the output phase information of phase shifter 402. When phase shifter 402 is adjusted to change the phase of the RF signal by a certain degree, the phase of Vout will also change by a corresponding degree. Since the frequency of Vout is very low, it can be easily and accurately measured and recorded in the baseband generation and processing circuit 408 to obtain the output phase of phase shifter 402. The baseband generation and processing circuit 408 acquires the phases of the two second baseband signals respectively, and obtains the actual phase of the RF signal through averaging. When the actual phase of phase shifter 402 has an error compared to the target phase, i.e., the preset phase-shifted phase, the baseband generation and processing circuit 408 can send a corresponding phase-shift control signal based on the phase error. Phase shifter 402 can be adjusted according to the phase-shift control signal until the error converges to an acceptable level. This achieves accurate calibration of the RF phase shifter.

[0074] In this embodiment, the phase of the second baseband signal Vout tracks the phase of the phase shifter. By measuring the change in the phase of Vout, the change in the phase shifter can be known. Therefore, when the change in the phase of Vout is found to be inconsistent with the expectation, the phase shifter is adjusted through the feedback signal, i.e., the phase shift control signal.

[0075] The baseband generation and processing circuit 408 also integrates a phase shift controller to generate a phase shift control signal according to the stored calibration phase information after calibration, so as to control the phase of the radio frequency signal output by the phase shifter to be the calibrated phase-shifted phase. In the working state, the local oscillator circuit 401 generates a radio frequency signal and outputs it to the phase shifter 402. Under the control of the phase shift command of the upper layer, the baseband generation and processing circuit 408 outputs a phase shift control signal to the phase shifter 402 according to the phase shift phase in the phase shift command. The phase shift control signal represents the calibrated phase information. The phase shifter 402 outputs a radio frequency signal that conforms to the phase shift phase according to the phase shift control signal and sends it to the driver amplifier 404. The driver amplifier 404 amplifies the output power of the radio frequency signal to drive the transmitting antenna system to convert it into electromagnetic waves and radiate it into free space.

[0076] like Figure 9The diagram illustrates a radio frequency (RF) receiving circuit according to an embodiment of this disclosure. The RF receiving circuit includes a receiving antenna system, a low-noise amplifier 409, a phase-shifting circuit (including a phase shifter and a calibration circuit), a local oscillator circuit, and a receiver mixer 410. The receiving antenna system receives external RF or microwave signals, the low-noise amplifier 409 amplifies the signal, the phase-shifting circuit adjusts the phase of the signal, and finally, the receiver mixer 410 down-converts the signal and outputs an intermediate frequency (IF) signal. In this example, the phase-shifting circuit includes a phase shifter 402 and a calibration circuit; the calibration circuit is shown within the dashed line in the diagram. In this example, the calibration circuit includes a quadrature coupler 403, a quadrature mixer 405, an amplifier 406, a mixer 407, and a baseband generation and processing circuit 408. The quadrature coupler 403 couples the output signal of the phase shifter 402 out at a certain ratio, ensuring that the coupled signal is large enough to accurately reflect the output performance of the phase shifter, while preventing the extraction of an excessively large signal from affecting the operation of the power amplifier. In this example, the output of the quadrature coupler 403 is a pair of radio frequency acquisition signals with a 90-degree phase difference (i.e., I in the figure). RF and Q RF (This is a high-frequency signal); the baseband generation and processing circuit 408 generates a first baseband signal for calibration (i.e., I in the figure). IF and Q IF The frequency of the first baseband signal can range from tens of kHz to hundreds of MHz for easy processing. The first baseband signal generated by the baseband generation and processing circuit 408 and the RF acquisition signal output by the quadrature coupler 403 are mixed in the quadrature mixer 405 to generate two signals with single-sideband characteristics, i.e., the aforementioned modulation signals. These are then amplified by the amplifier 406 and sent to the mixer 407. The mixer 407 also receives the local oscillator signal from the local oscillator circuit 401 (which can be the local oscillator circuit in the RF transmitting circuit). The mixer 407 performs down-conversion processing and outputs two second baseband signals, Vout. These Vout signals are related to I... IF and Q IFWhile having the same frequency, it contains the output phase information of phase shifter 402. When phase shifter 402 is adjusted to change the phase of the RF signal by a certain degree, the phase of Vout will also change by a corresponding degree. Since the frequency of Vout is very low, it can be easily and accurately measured and recorded in the baseband generation and processing circuit 408 to obtain the output phase of phase shifter 402. The baseband generation and processing circuit 408 acquires the phases of the two second baseband signals respectively, and obtains the actual phase of the RF signal through averaging. When the actual phase of phase shifter 402 has an error compared to the target phase, the baseband generation and processing circuit 408 can send a corresponding phase shift control signal based on the phase error. Phase shifter 402 can be adjusted according to the phase shift control signal until the error converges to an acceptable level. This achieves accurate calibration of the RF phase shifter.

[0077] The baseband generation and processing circuit 408 also integrates a phase shift controller to generate a phase shift control signal according to the stored calibration phase information after calibration, so as to control the phase of the radio frequency signal output by the phase shifter to be the calibrated phase-shifted phase. Taking a radar sensor containing this radio frequency receiving circuit as an example, in the working state, the local oscillator circuit 401 generates a radio frequency signal and outputs it to the phase shifter 402 and the receiver mixer 410, and the receiving antenna system converts electromagnetic waves in free space into radio frequency received signals and amplifies them through the low-noise amplifier 402 before outputting them. Under the control of the upper-level phase shift command, the baseband generation and processing circuit 408 outputs a phase shift control signal to the phase shifter 402 according to the phase shift phase in the phase shift command, wherein the phase shift control signal represents the calibrated phase information. The phase shifter 402 outputs a radio frequency received signal that conforms to the phase shift phase according to the phase shift control signal and sends it to the receiver mixer 410. The receiver mixer 410 uses the local oscillator signal to perform down-conversion processing on the phase-shifted radio frequency received signal to output a baseband signal with phase shift information. The baseband signal is used by subsequent circuits to calculate information about the target object detected in the radiation direction under this phased array.

[0078] like Figure 10 The diagram shows another radio frequency (RF) transmitting circuit provided in this embodiment. This RF transmitting circuit includes a local oscillator circuit 501, a phase shifting circuit, an amplifier 504, and a transmitting antenna system. The phase shifting circuit includes a phase shifter 502 and a calibration circuit; the calibration circuit is shown within the dashed line in the figure. Compared to... Figure 8 The calibration circuit in this embodiment includes a single-ended coupler 503 (i.e., the aforementioned RF acquisition circuit), a mixer 505 (i.e., the aforementioned modulation circuit), an amplifier 506, a frequency conversion circuit (including a quadrature coupler 507 and a quadrature mixer 508), and a baseband generation and processing circuit 509. The single-ended coupler 503 couples out the output signal of the phase shifter 502 at a certain ratio and inputs it to the mixer 505. The baseband generation and processing circuit 509 generates a first baseband signal (i.e., V in the figure) used for calibration.IF The first baseband signal generated by the baseband generation and processing circuit 508 and the radio frequency acquisition signal output by the coupler 503 are mixed in the mixer 505 (V RF -V IF or V RF +V IF After this, a signal with single-sideband characteristics—the modulated signal—is generated. This modulated signal is amplified by amplifier 506 and then fed into quadrature mixer 508. Quadrature mixer 508 also receives the local oscillator signal from local oscillator circuit 501. In this example, the local oscillator signal output from local oscillator circuit 501, upon entering the calibration circuit, passes through quadrature coupler 507 to generate two local oscillator signals with a 90-degree phase difference (i.e., I in the figure). RF and Q RF The quadrature mixer 508 performs down-conversion processing to obtain baseband signals Iout and Qout with an orthogonal relationship. These Iout and Qout are then compared with V... IF While having the same frequency, it contains the output phase information of phase shifter 502. The phases Iout and Qout can be precisely measured and recorded in the baseband generation and processing circuit 408 to obtain the output phase of phase shifter 502. The baseband generation and processing circuit 408 acquires the phases of the two second baseband signals respectively, and obtains the actual phase of the RF signal through averaging. When the actual phase of phase shifter 502 has an error compared to the target phase after measurement, the baseband generation and processing circuit 509 can send a corresponding phase shift control signal based on the phase error. Phase shifter 502 can be adjusted according to the phase shift control signal until the error converges to an acceptable level. This achieves precise calibration of the RF phase shifter.

[0079] like Figure 11 The diagram shows another radio frequency (RF) receiving circuit provided in an embodiment of this disclosure. This RF receiving circuit includes a receiving antenna system, a low-noise amplifier 510, a phase-shifting circuit, a local oscillator circuit, and a receiver mixer 511. In this example, the phase-shifting circuit includes a phase shifter 502 and a calibration circuit; the calibration circuit is shown within the dashed line in the figure. In this example, the calibration circuit includes a quadrature coupler 503, a mixer 505, an amplifier 506, a quadrature mixer 508, a quadrature coupler 507, and a baseband generation and processing circuit 509. Compared to... Figure 9 In this embodiment, the phase shifter output terminal of the calibration circuit uses a single-ended coupler 503. The single-ended coupler 503 outputs the radio frequency acquisition signal (i.e., V in the figure). RF (This is a high-frequency signal), and the baseband generation and processing circuit 509 generates a first baseband signal for calibration (i.e., V in the figure). IFThe first baseband signal generated by the baseband generation and processing circuit 509 and the RF acquisition signal output by the coupler 503 are mixed in the mixer 505. The resulting modulated signal is then amplified by the amplifier 506 and sent to the quadrature mixer 508. The quadrature mixer 508 also receives the local oscillator signal from the local oscillator circuit 501 (which can be the local oscillator circuit in the RF transmitter circuit). In this example, the local oscillator signal output by the local oscillator circuit 501, when entering the calibration circuit, is converted into two local oscillator signals with a 90-degree phase difference by the quadrature coupler 507 (i.e., I in the figure). RF and Q RF The quadrature mixer 508 performs down-conversion processing to obtain baseband signals Iout and Qout with an orthogonal relationship. These Iout and Qout are then compared with V... IF While having the same frequency, it contains the output phase information of phase shifter 502. Since the frequencies of Iout and Qout are very low, they can be easily and accurately measured and recorded in the baseband generation and processing circuit 509 to obtain the actual phase of phase shifter 502. When the actual phase of phase shifter 502 has an error compared to the target phase, the baseband generation and processing circuit 509 can send a corresponding phase shift control signal based on the phase error. Phase shifter 502 can then be adjusted according to the phase shift control signal until the error converges to an acceptable level. This achieves precise calibration of the RF phase shifter.

[0080] like Figure 12 As shown, another radio frequency (RF) transmitting circuit provided in this embodiment is illustrated. In this example, the calibration circuit includes a single-ended coupler (i.e., the aforementioned RF acquisition circuit), a first mixer (i.e., the aforementioned modulation circuit), an amplifier, a second mixer (i.e., the aforementioned frequency conversion circuit), and a baseband generation and processing circuit (including the aforementioned baseband signal generation circuit and phase calibration circuit). This example employs a single-ended signal processing method. A single-ended coupler couples out an RF acquisition signal, which is then mixed with the first baseband signal output from the baseband signal generation and processing circuit. The resulting modulation signal is amplified by the amplifier and input to the second mixer for down-conversion processing to obtain a second baseband signal. The second baseband signal contains the actual phase information of the phase shifter. The baseband generation and processing circuit extracts this phase information, performs error judgment, and sends a phase shift control signal to the phase shifter based on the judgment result. A similar configuration can be used for the RF receiving circuit, which will not be described in detail in this embodiment.

[0081] In an exemplary embodiment, this disclosure also provides a calibration method for a phase shifter, such as... Figure 13 As shown, it includes the following steps:

[0082] Step S1: Obtain the radio frequency signal with actual phase output by the phase shifter;

[0083] Step S2: Modulate the radio frequency signal using the first baseband signal;

[0084] Step S3: Downconvert the modulated radio frequency signal to baseband to obtain a second baseband signal containing the actual phase;

[0085] Step S4: Obtain the actual phase in the second baseband signal, determine the calibration phase of the phase shifter based on the phase deviation between the actual phase and the preset phase shift phase, and send a phase shift control signal to the phase shifter based on the calibration phase.

[0086] The implementation subject, implementation process, and effects of the method are described in the foregoing embodiments and will not be repeated here.

[0087] In an exemplary embodiment, this disclosure also provides a radar sensor, which may include the aforementioned radio frequency transmitting circuit and / or radio frequency receiving circuit. The radar sensor uses the detection signal wave emitted by the radio frequency transmitting circuit and the echo signal wave received by the radio frequency receiving circuit to measure physical quantities between itself and surrounding environmental targets, such as measuring relative velocity, relative angle, relative distance, and at least one of the three-dimensional contours of the target.

[0088] For example, the radar sensor includes a radio frequency (RF) transmitting circuit and / or a radio frequency (RF) receiving circuit. Here, both the RF transmitting circuit and the RF receiving circuit have their circuit structures determined based on the surrounding environment measured by the radar sensor, to transmit detection signal waves and receive echo signal waves in a preset frequency band or at a fixed frequency, and to perform signal processing on the corresponding changing electrical signals. The RF transmitting circuit or the RF receiving circuit is the corresponding circuit provided in any of the above examples, to achieve phased array detection or reduce radar interference.

[0089] Specifically, the radio frequency (RF) transmitting circuit generates a chirp signal (such as an FMCW signal) according to a preset continuous frequency modulation method; the RF transmitting signal is obtained through frequency multiplication, and after phase shifting processing using a phase shifting circuit, it is fed to the transmitting antenna to transmit the corresponding detection signal wave. When the detection signal wave is reflected by an object, an echo signal wave is formed. The echo signal wave is converted into an RF receiving signal by a receiving antenna. The RF receiving circuit is used to perform down-conversion, filtering, analog-to-digital conversion, and other processing on the RF receiving signal using the RF transmitting signal (i.e., the aforementioned local oscillator signal) to output a baseband digital signal representing the difference frequency between the detection signal wave and the echo signal wave. The radar sensor may also include a signal processor, which can be connected to the RF receiving circuit to extract measurement information from the baseband digital signal through signal processing and output measurement data. Since the measurement data includes phase shifting, it can help determine the angle information of the detected target, etc. The signal processing includes digital signal processing calculations based on phase, frequency, and time domain of at least one signal to be processed provided by at least one receiving antenna. The measurement data includes at least one of the following: distance data representing the relative distance to at least one detected target; velocity data representing the relative speed of at least one detected target; angle data representing the relative angle of at least one detected target, etc.

[0090] In an exemplary embodiment, this disclosure also provides an electronic device that includes at least one of the aforementioned phase-shifting circuit, the aforementioned radio frequency transmitting circuit, the aforementioned radio frequency receiving circuit, and the aforementioned radar sensor.

[0091] Exemplarily, the electronic device includes: a device body; and at least one wireless device disposed on the device body, such as a phase-shifting circuit, a radio frequency transmitting circuit, a radio frequency receiving circuit, or a radar sensor as described in the above embodiments. The device body is a structure that carries and is signal-connected to the wireless device. The wireless device transmits and / or receives radio signals processed by a phase shifter to achieve functions such as target detection and / or communication within the beam scanning range, 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.

[0092] In an optional embodiment, the electronic device comprising the device body and at least one of the aforementioned wireless devices can be a component or product applied in fields such as smart homes, transportation, smart homes, consumer electronics, surveillance, industrial automation, in-cabin detection, 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 equipment (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 detection in automobiles, indoor personnel monitoring, smart medical devices, and consumer electronic devices.

[0093] In the description of the embodiments of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the meaning of the above terms in this disclosure according to the circumstances.

[0094] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

Claims

1. A calibration circuit for a phase shifter, characterized in that, It includes a phase acquisition circuit and a phase calibration circuit, wherein: The phase acquisition circuit, coupled to the phase shifter, is used to modulate the radio frequency sampling signal acquired by the phase shifter using a first baseband signal, downconvert the obtained modulated signal to baseband, and output a second baseband signal containing the actual phase; the actual phase is the phase of the radio frequency signal output by the phase shifter; wherein, the first baseband signal is an intermediate frequency signal or a low frequency signal with a preset initial phase; The phase calibration circuit is coupled to the phase acquisition circuit to receive the second baseband signal, and is used to acquire the actual phase in the second baseband signal. Based on the phase deviation between the actual phase and the preset phase shifting phase, the calibration phase information is determined and stored so as to generate a phase shifting control signal to be sent to the phase shifter based on the calibration phase.

2. The calibration circuit according to claim 1, characterized in that, The second baseband signal output by the phase acquisition circuit is an orthogonal signal.

3. The calibration circuit according to claim 1, characterized in that, The phase acquisition circuit includes an radio frequency acquisition circuit, a modulation circuit, and a frequency conversion circuit, wherein: The radio frequency acquisition circuit is coupled to the phase shifter and is used to acquire the radio frequency signal output by the phase shifter to output a radio frequency sampling signal. The modulation circuit is coupled to the radio frequency acquisition circuit and receives the first baseband signal. It is used to modulate the radio frequency sampling signal with the first baseband signal to output a modulation signal containing the actual phase. The frequency conversion circuit is coupled to the modulation circuit and receives the local oscillator signal. It is used to perform down-conversion processing on the modulation signal using the local oscillator signal to generate a second baseband signal containing the actual phase.

4. The calibration circuit according to claim 3, characterized in that, The first baseband signal is a quadrature signal, including an in-phase first baseband signal and a quadrature first baseband signal; The radio frequency acquisition circuit includes a first quadrature coupler, which has a non-inverting output terminal and a quadrature output terminal. The modulation circuit includes a first modulator connected to the non-inverting output terminal and a second modulator connected to the quadrature output terminal, wherein: The first quadrature coupler is coupled to the phase shifter and is used to acquire the radio frequency signal output by the phase shifter so that the output radio frequency sampling signal is an orthogonal signal, including in-phase radio frequency sampling signal and quadrature radio frequency sampling signal; The first modulator is used to modulate the in-phase radio frequency sampling signal using the in-phase first baseband signal, and the second modulator is used to modulate the quadrature radio frequency sampling signal using the quadrature first baseband signal, so that the modulated signal output by the modulation circuit is also a quadrature signal.

5. The calibration circuit according to claim 3, characterized in that, The first baseband signal is a single signal; The radio frequency acquisition circuit includes a single-ended coupler; and The modulation circuit uses the first baseband signal to modulate the received radio frequency sampling signal to output the modulated signal; wherein the modulated signal is a single signal or a quadrature signal.

6. The calibration circuit according to claim 3, characterized in that, The modulation signal is an orthogonal signal; The frequency conversion circuit includes a first mixer that receives each signal in the modulation signal; wherein each first mixer uses the local oscillator signal to perform down-conversion processing on a corresponding signal in the modulation signal so that the second baseband signal output by the frequency conversion circuit is an orthogonal signal.

7. The calibration circuit according to claim 3, characterized in that, The modulation signal is a single signal; The frequency conversion circuit includes a second quadrature coupler and two second mixers, wherein, The second quadrature coupler is coupled to the local oscillator circuit and is used to convert one local oscillator signal output by the local oscillator circuit into a quadrature signal and output it. The second quadrature coupler includes a non-inverting output terminal for outputting a non-inverting local oscillator signal and a quadrature output terminal for outputting a quadrature local oscillator signal. A second mixer is connected to the in-phase output terminal for outputting the in-phase local oscillator signal, and is used to down-convert the modulation signal using the in-phase local oscillator signal. Another second mixer is connected to the quadrature output terminal for outputting the quadrature local oscillator signal, and is used to down-convert the modulation signal using the quadrature local oscillator signal, so that the second baseband signal output by the frequency conversion circuit is a quadrature second baseband signal that contains the actual phase.

8. The calibration circuit according to claim 1, characterized in that, Each signal transmission path in the phase acquisition circuit is equipped with an amplifier to amplify the signal.

9. The calibration circuit according to claim 8, characterized in that, The signal amplified by the amplifier is the modulation signal.

10. The calibration circuit according to claim 8, characterized in that, The signal transmission path includes one transmission path for transmitting single-ended signals, or two transmission paths for transmitting orthogonal signals.

11. The calibration circuit according to claim 1, characterized in that, The phase calibration circuit includes: an ADC and a digital signal processor; The ADC is coupled to the phase acquisition circuit and is used to perform analog-to-digital conversion on the second baseband signal and output the corresponding second baseband digital signal. A digital signal processor is coupled to the ADC and is used to determine the phase deviation of the phase shifter by detecting the phase difference between a preset phase shift phase and the actual phase in the second baseband digital signal; and to store the phase deviation or compensation information determined based on the phase deviation as the calibration phase information for generating the phase shift control signal.

12. The calibration circuit according to claim 11, characterized in that, The ADC is also used to receive a first baseband signal, to perform analog-to-digital conversion on the first baseband signal, and to output a corresponding first baseband digital signal; The digital signal processor is used to extract the actual phase by detecting the phase difference between the first baseband digital signal and the second baseband digital signal.

13. The calibration circuit according to claim 11, characterized in that, The digital signal processor detects the phase difference between the preset phase-shifted phase and the actual phase in the frequency domain.

14. A phase-shifting circuit, characterized in that, Includes a phase shifter controller, a phase shifter, and a calibration circuit as described in any one of claims 1-13, wherein: The phase shift controller is coupled to the calibration circuit and the phase shifter, and receives a phase shift command. It is used to output a phase shift control signal according to the phase shift phase in the phase shift command and the corresponding stored calibration phase information. The phase shifter is used to perform phase shifting processing on the radio frequency signal according to the phase shift control signal.

15. The phase-shifting circuit according to claim 14, characterized in that, The phase shifter includes an IQ phase shifter or a transmission line phase shifter.

16. A radio frequency transmitting circuit, characterized in that, The system includes a local oscillator circuit, a phase-shifting circuit as described in claim 14 or 15, and a transmitting antenna system. The local oscillator circuit outputs the generated radio frequency transmission signal to the phase-shifting circuit, and the phase-shifting circuit shifts the phase of the radio frequency transmission signal and inputs it into the transmitting antenna system to convert it into electromagnetic waves for radiation.

17. A radio frequency receiving circuit, characterized in that, The device includes a receiving antenna system, a phase-shifting circuit as described in claim 14 or 15, a local oscillator circuit, and a mixer. The receiving antenna system converts electromagnetic waves into radio frequency received signals and outputs them to the phase-shifting circuit. The phase-shifted radio frequency received signal and the local oscillator signal output by the local oscillator circuit are input to the mixer to output a down-converted difference frequency signal.

18. A radar sensor, characterized in that, Includes the radio frequency transmitting circuit as described in claim 16, and / or the radio frequency receiving circuit as described in claim 17.

19. An electronic device, characterized in that, It includes at least one of the phase-shifting circuit as described in claim 14 or 15, the radio frequency transmitting circuit as described in claim 16, the radio frequency receiving circuit as described in claim 17, and the radar sensor as described in claim 18.

20. A calibration method for a phase shifter, characterized in that, include: Acquire the radio frequency signal with actual phase output from the phase shifter; The radio frequency signal is modulated using a first baseband signal, wherein the first baseband signal is an intermediate frequency signal or a low frequency signal with a preset initial phase; The modulated radio frequency signal is down-converted to the baseband to obtain a second baseband signal containing the actual phase. The actual phase in the second baseband signal is obtained, and the calibration phase of the phase shifter is determined based on the phase deviation between the actual phase and the preset phase shift phase. A phase shift control signal is then sent to the phase shifter based on the calibration phase.

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