Interference cancellation circuit and parameter calibration method

Abstract

An interference cancellation circuit and a parameter calibration method. The interference cancellation circuit is applied to an integrated sensing and communication system, and comprises a first port, a second port and a transmission feed module, wherein the first port is connected to a transmission port of a chip; the second port is connected to a receiving port of the chip; the transmission feed module comprises a third port and a fourth port, the third port is connected to the first port, and the fourth port is connected to the second port; the first port is used for receiving a transmitted signal from the transmission port of the chip; the transmission feed module is used for performing amplitude modulation and / or phase shift on the transmitted signal to generate a first signal, and inputting the first signal into the second port by means of the fourth port; and the second port is used for outputting the first signal, which is transmitted to the receiving port of the chip for offsetting an interference signal of the receiving port of the chip. By means of the embodiments of the present application, interference of an interference signal on a received signal can be reduced.

Description

Interference elimination circuit and parameter calibration method

[0001] This application claims priority to the Chinese patent application with application number 202310949387.4 filed with the State Intellectual Property Office of China on July 29, 2023, and priority to the Chinese patent application with the invention name “Interference Elimination Circuit and Parameter Calibration Method”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to an interference elimination circuit and a parameter calibration method. Background Art

[0003] An integrated sensing and communication (ISAC) system refers to a system that has both communication and perception functions, and can also be called an integrated synaesthesia system.

[0004] Exemplarily, the synaesthesia system may include a chip and an antenna, wherein the chip is used to output a transmit signal, and the antenna is used to transmit the transmit signal and receive the target's echo signal (i.e., a received signal). The chip is also used to compare the received signal with the waveform of the transmit signal to obtain target information, thereby realizing the perception function. Exemplarily, the synaesthesia system may adopt a single antenna architecture or a dual antenna architecture. When the synaesthesia system adopts a dual antenna architecture, the antenna may include a transmitting (transmitter, Tx) antenna and a receiving (receiver, Rx) antenna, which are used to transmit the transmit signal and receive the receive signal, respectively.

[0005] However, the signals received by the Tonggan Tianyi system include interference signals in addition to the received signal. These include direct interference signals from the transmitting antenna that are directly received by the receiving antenna, coupled interference signals between the transmitting and receiving antenna feeders, coupled interference signals within the chip's RF and IF sections, and coupled interference signals between chip pins. These interference signals are often much larger than the received signal and are similar to the received signal, making signal separation difficult and seriously interfering with target detection.

[0006] Summary of the Invention

[0007] The embodiments of the present application disclose an interference cancellation circuit and a parameter calibration method, which can reduce the interference of interference signals on received signals, facilitate the separation of received signals, and facilitate the detection of targets at longer distances and with greater precision.

[0008] In a first aspect, an embodiment of the present application provides an interference elimination circuit, which is applied to a synaesthesia system, and includes a first port, a second port, and a transmitting feed module; the first port is connected to the transmitting port of the chip, the second port is connected to the receiving port of the chip, and the transmitting feed module includes a third port and a fourth port, the third port is connected to the first port, and the fourth port is connected to the second port; the first port is used to receive a transmitting signal from the transmitting port of the chip; the transmitting feed module is used to amplitude modulate and / or phase shift the transmitting signal to generate a first signal, and input the first signal to the second port through the fourth port; the second port is used to output the first signal; wherein, the first signal is transmitted to the receiving port of the chip to offset the interference signal of the receiving port of the chip.

[0009] In an embodiment of the present application, the interference cancellation circuit can be applied to a telepathic system or a single-antenna radar system. The interference cancellation circuit can be arranged between the chip and the antenna of the telepathic system to eliminate the interference signal received by the chip. Since the interference signal received by the receiving port of the chip is generated by coupling with the transmitted signal, it has the same frequency as the transmitted signal, but may be different in amplitude and phase. Therefore, the transmitting feed module obtains a first signal that can offset the interference signal by performing amplitude modulation and / or phase modulation on the transmitted signal. The signal received by the receiving port of the chip includes a received signal, a first signal and an interference signal, and the received signal is the echo signal of the target received by the antenna. The first signal cancels the interference signal, that is, the power of the superimposed signal of the first signal and the interference signal is less than the power of the interference signal, thereby reducing the interference of the interference signal on the received signal, which is beneficial to the separation of the received signal, so as to facilitate the detection of more precise targets at longer distances.

[0010] In combination with the first aspect, in one possible implementation, the transmitting feed module includes an attenuated phase shifting module and a directional coupling module, the attenuated phase shifting module and the directional coupling module are connected in series or in parallel, the attenuated phase shifting module is used to perform amplitude modulation and / or phase modulation on the transmitting signal, and the directional coupling module is used to separate the transmitting signal from the receiving signal.

[0011] In an embodiment of the present application, forward and backward signal separation is performed through a directional coupling module to achieve separation of the transmit signal and the receive signal, so that the chip can transmit and receive signals at the same time, and the transmit signal is amplitude modulated and / or phase modulated through an attenuation phase shifting module to generate a signal for the interference signal, thereby reducing interference.

[0012] In combination with the first aspect, in a possible implementation, the transmitting feed module includes an attenuated phase shifting module and a directional coupling module, the directional coupling module includes a fifth port and a sixth port; the input port of the attenuated phase shifting module is connected to the third port, the output port of the attenuated phase shifting module is connected to the fifth port, and the fourth port is connected to the sixth port; the attenuated phase shifting module is used to perform amplitude modulation and / or phase shifting on the transmitting signal to generate a second signal, and output the second signal to the directional coupling module; the directional coupling module is used to generate the first signal based on the second signal, and output the first signal to the fourth port through the sixth port; the fourth port is used to output the first signal.

[0013] In an embodiment of the present application, after the directional coupling module receives the second signal through the fifth port, it generates the first signal at the sixth port. The fifth port can also be called the incident port of the second signal, and the sixth port can also be called the isolation port of the second signal. The attenuation phase shifting module is connected in series with the directional coupling module. The amplitude and / or phase of the second signal can be adjusted through the attenuation phase shifting module, thereby indirectly adjusting the amplitude and / or phase of the first signal, so that the first signal can offset the interference signal. It can be understood that the embodiment of the present application can reasonably use the signal generated by the isolation port when the directional coupler transmits the transmission signal to offset the interference signal, thereby making the interference elimination operation simpler.

[0014] In combination with the first aspect, in a possible implementation, the transmitting feed module includes an attenuated phase shifting module and a directional coupling module, the directional coupling module includes a fifth port and a sixth port; the input port of the attenuated phase shifting module is connected to the third port, the output port of the attenuated phase shifting module is connected to the fourth port, the fifth port is connected to the third port, and the sixth port is connected to the fourth port; the attenuated phase shifting module is used to perform amplitude modulation and / or phase shifting on the transmitting signal to generate a third signal, and transmit the third signal to the fourth port; the directional coupling module is used to generate a fourth signal based on the transmitting signal and transmit the fourth signal to the fourth port; the fourth port is used to output the first signal, and the first signal is composed of the third signal and the fourth signal.

[0015] In an embodiment of the present application, after the directional coupling module receives the transmission signal through the fifth port, it generates the fourth signal at the sixth port. The fifth port can also be called the incident port of the transmission signal, and the sixth port can also be called the isolation port of the transmission signal. The attenuation phase shifting module is connected in parallel with the directional coupling module to respectively generate a third signal and a fourth signal for offsetting the interference signal. The first signal received by the fourth port is the superposition signal of the third signal and the fourth signal. The amplitude and phase of the third signal can be adjusted by the attenuation phase shifting module so that the first signal can offset the interference signal. It can be understood that the embodiment of the present application can reasonably use the signal generated by the isolation port when the directional coupler transmits the transmission signal to offset the interference signal, thereby making the interference elimination operation simpler.

[0016] In combination with the first aspect, in a possible implementation, the circuit further includes a seventh port, and the directional coupling module further includes an eighth port; the seventh port is connected to the antenna, and the eighth port is connected to the seventh port; the directional coupling module is further used to generate a fifth signal based on the second signal or the transmit signal, and output the fifth signal to the seventh port through the eighth port; the seventh port is used to output the fifth signal, and the fifth signal is transmitted to the antenna.

[0017] In this embodiment of the present application, the eighth port is a coupling port for a second signal or a transmit signal. After receiving the second signal or the transmit signal through the fifth port, the directional coupling module outputs a fifth signal through the eighth port. After receiving the fifth signal from the fifth port, the seventh port transmits the fifth signal to the antenna, causing the antenna to transmit the fifth signal, thereby achieving signal transmission.

[0018] In combination with the first aspect, in a possible implementation, the circuit further includes a matching module, the eighth port is connected to the seventh port through the matching module, the matching module includes a ninth port and a tenth port, the ninth port is connected to the eighth port, and the tenth port is connected to the seventh port; the matching module is used to receive the fifth signal through the ninth port, output the reflected signal through the ninth port, and output the fifth signal to the seventh port through the tenth port; the directional coupling module is also used to output the reflected signal to the fourth port through the sixth port; the fourth port is also used to output the reflected signal, and the reflected signal is used to offset the interference signal.

[0019] In an embodiment of the present application, the matching module is used to perform impedance matching. After the ninth port of the matching module receives the fifth signal, the fifth signal is transmitted by the matching module to generate a reflection signal, and the reflection signal is output through the ninth port. The reflection signal is transmitted to the eighth port through the ninth port. The directional coupling module transmits the reflection signal to the fourth port through the sixth port, and the fourth port transmits the reflection signal to the second port, and the second port outputs the reflection signal so that the reflection signal is transmitted to the receiving port of the chip. The embodiment of the present application uses the reflection signal and the first signal to offset the interference signal, thereby better eliminating interference.

[0020] With reference to the first aspect, in a possible implementation, the matching module includes at least one variable capacitor or at least one variable resistor, and the at least one variable capacitor or at least one variable resistor is used to adjust the phase of the reflected signal.

[0021] In the embodiment of the present application, the phase of the reflected signal can be adjusted by adjusting the value of at least one variable capacitor or at least one variable resistor, so that the reflected signal can better offset the interference signal.

[0022] With reference to the first aspect, in a possible implementation manner, the power of the reflected signal is determined by a reflection coefficient of the ninth port.

[0023] In the embodiment of the present application, the power or amplitude of the reflected signal is determined by the reflection coefficient of the ninth port, that is, the power or amplitude of the reflected signal can be adjusted by changing the reflection coefficient of the ninth port, so that the reflected signal can better offset the interference signal.

[0024] In combination with the first aspect, in one possible implementation, the seventh port is further used to receive a received signal from the antenna and output the received signal to the eighth port, where the received signal is a signal received by the antenna; the directional coupling module is further used to receive the received signal through the eighth port and output the received signal to the fourth port through the sixth port; and the fourth port is further used to output the received signal.

[0025] In the embodiment of the present application, the received signal is an echo signal of a target received by the antenna. For example, the received signal may be an echo signal resulting from the fifth signal being reflected by the target after the antenna transmits the fifth signal. The eighth port is the input port for the received signal, and the sixth port is the pass-through port for the received signal. Therefore, the received signal can be transmitted to the receiving port of the chip via the directional coupling module, thereby isolating the transmit signal from the receive signal through the directional coupling module, enabling simultaneous transmission and reception.

[0026] In combination with the first aspect, the circuit further includes a first switch and a second switch, the first switch including a first fixed terminal, a first movable terminal, and a second movable terminal, and the second switch including a second fixed terminal, a third movable terminal, and a fourth movable terminal; the first fixed terminal is connected to the third port, the first movable terminal is connected to the first port, and the second movable terminal is connected to a reference ground; the second fixed terminal is connected to the fourth port, the third movable terminal is connected to the second port, and the fourth movable terminal is connected to the first port;

[0027] The directional coupling module is further configured to transmit a received signal to the second port when the first fixed end is connected to the second movable end and the second fixed end is connected to the third movable end, and the second port is configured to output the received signal; wherein the received signal is a signal received by the seventh port from the antenna; or

[0028] The directional coupling module is further configured to transmit the transmit signal to the seventh port when the first fixed end is connected to the second movable end, and the second fixed end is connected to the fourth movable end.

[0029] In this embodiment of the present application, when the first fixed terminal is connected to the second movable terminal, and the second fixed terminal is connected to the third movable terminal, the path between the directional coupling module and the chip's receive port is connected by the second switch, and the chip is in communication receive mode. The eighth port serves as the input port for received signals, and the sixth port serves as the pass-through port for received signals. Therefore, after the antenna receives a receive signal, the receive signal can be transmitted to the chip's receive port via the seventh port, the directional coupling module, and the second port.

[0030] When the first fixed end is connected to the second movable end, and the second fixed end is connected to the fourth movable end, the path between the directional coupling module and the chip's transmit port is turned on by the second switch, and the chip processes the communication transmit mode. The sixth port is the transmit signal input port, and the eighth port is the transmit signal pass-through port. Therefore, after the chip's transmit port outputs the transmit signal, the transmit signal is transmitted to the seventh port through the directional coupling module, and the seventh port transmits the transmit signal to the antenna, so that the antenna transmits the transmit signal. In the embodiment of the present application, the first switch disconnects the path between the chip's transmit port and the attenuation phase shift module, so that the chip is not affected by the attenuation phase shift module in the communication transmit mode or the communication receive mode, thereby ensuring the stability of the chip's communication performance.

[0031] With reference to the first aspect, in a possible implementation manner, the power of the fifth signal is determined by the power of the second signal or the transmit signal and a coupling coefficient of the directional coupling module.

[0032] With reference to the first aspect, in a possible implementation manner, the isolation coefficient of the directional coupling module is determined by the self-coupling coefficient of the chip.

[0033] In this embodiment of the present application, the interference signal includes a signal generated by chip self-coupling. Specifically, the power or amplitude of the interference signal is determined by the chip's self-coupling coefficient and the power or amplitude of the transmitted signal, while the power or amplitude of the first signal is determined by the isolation coefficient of the directional coupling module and the power or amplitude of the transmitted signal. Therefore, the isolation coefficient of the directional coupling module can be determined by the chip's self-coupling coefficient, enabling the first signal to better cancel out the interference signal.

[0034] In combination with the first aspect, in a possible implementation, the attenuation and phase shifting module includes an attenuator and a phase shifter, the attenuator and the phase shifter are connected in series, the attenuator is used to amplitude modulate the transmit signal, and the phase shifter is used to phase modulate the transmit signal.

[0035] With reference to the first aspect, in a possible implementation manner, the power of the first signal is determined by the power of the transmit signal and the isolation coefficient of the directional coupling module.

[0036] With reference to the first aspect, in a possible implementation, the interference signal includes at least one of the following: a transmission-reception coupling interference signal of the chip, and a direct path interference signal received by the antenna after the antenna transmits a signal.

[0037] In second aspect, an embodiment of the present application provides a parameter calibration method, which is applied to a controller, the controller is connected to an interference elimination circuit, and the interference elimination circuit is used to eliminate the interference signal of the chip. The method includes: obtaining a first gradient value of a first parameter, the first gradient value is used to indicate the degree of influence of the first parameter on the power of the interference signal, and the first parameter is a parameter in the interference elimination circuit; adjusting the value of the first parameter according to the first gradient value until the power of the interference signal meets the first condition.

[0038] In this embodiment of the present application, the interference signal is a signal other than the received signal in the signal received by the chip, and the received signal is a signal received by the antenna. The controller gradually adjusts the parameters of the interference cancellation circuit according to the first gradient value so that the interference cancellation circuit can better cancel the interference signal of the chip. In other words, the controller gradually adjusts the parameters of the interference cancellation circuit according to the first gradient value, gradually reducing the power of the interference signal until the power of the interference signal meets the requirement.

[0039] With reference to the second aspect, in a possible implementation manner, the first condition includes that the power of the interference signal is less than a first threshold.

[0040] In the embodiment of the present application, the first threshold value can be determined based on the service requirements or capabilities of the chip. By adjusting the value of the first parameter, the power of the interference signal of the chip is made less than the first threshold value, so that the interference of the chip can meet the requirements, for example, the chip can separate the interference signal from the received signal.

[0041] In combination with the second aspect, in a possible implementation, obtaining a first gradient value of the first parameter includes: when the first parameter is a first value, controlling the chip to output a first transmit signal, and obtaining a first power value of an interference signal corresponding to the first transmit signal; when the first parameter is a second value, controlling the chip to output a second transmit signal, and obtaining a second power value of an interference signal corresponding to the second transmit signal; and determining the first gradient value based on the first value, the second value, the first power value, and the second power value.

[0042] In the embodiment of the present application, by obtaining the value of the adjusted first parameter and respectively obtaining the power values ​​of the interference signal when the first parameter takes different values, the influence of the first parameter on the power of the interference signal can be accurately obtained.

[0043] In combination with the second aspect, in a possible implementation, the interference elimination circuit includes at least one of an attenuation phase shift module, a directional coupling module, and a matching module, and the first parameter includes at least one of the following: the attenuation amount of the attenuation phase shift module, the phase shift amount of the attenuation phase shift module, and the phase shift amount of the matching module.

[0044] In combination with the second aspect, in a possible implementation manner, the method further includes: saving the value of the first parameter.

[0045] In an embodiment of the present application, after the controller adjusts the first parameter so that the power of the interference signal meets the first condition, the value of the first parameter is saved so that the value of the first parameter can be used in the subsequent process of the chip receiving the transmitted signal to make the interference signal of the chip meet the first condition without repeating the calibration and adjustment of the parameters.

[0046] In a third aspect, an embodiment of the present application provides a chip, which includes a packaging substrate and a bare chip, and the bare chip is provided with an interference elimination circuit as described in the first aspect and any possible implementation of the first aspect, and the packaging substrate is used to package the bare chip.

[0047] In a fourth aspect, an embodiment of the present application provides a wireless transceiver system, wherein the wireless transceiver includes a chip, an antenna, and an interference cancellation circuit as described in the first aspect and any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The following is an introduction to the drawings related to the embodiments of this application.

[0049] 1A-1C are schematic structural diagrams of a synaesthesia system provided in an embodiment of the present application;

[0050] FIG2 is a schematic diagram of a communication scenario of a synaesthesia system provided in an embodiment of the present application;

[0051] FIG3 is a schematic diagram of the structure of a system with a single antenna architecture provided in an embodiment of the present application;

[0052] FIG4 is a schematic structural diagram of an interference elimination circuit provided in an embodiment of the present application;

[0053] FIG5 is a schematic structural diagram of a directional coupling module provided in an embodiment of the present application;

[0054] FIG6 is a schematic structural diagram of an attenuation phase shifting module provided in an embodiment of the present application;

[0055] FIG7 is a schematic structural diagram of another interference elimination circuit provided in an embodiment of the present application;

[0056] 8A-8C are schematic structural diagrams of another interference elimination circuit provided in an embodiment of the present application;

[0057] FIG9 is a schematic structural diagram of another interference elimination circuit provided in an embodiment of the present application;

[0058] FIG10 is a schematic structural diagram of another interference elimination circuit provided in an embodiment of the present application;

[0059] 11A-11C are schematic structural diagrams of another interference elimination circuit provided in an embodiment of the present application;

[0060] FIG12 is a flow chart of a parameter calibration method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of this application clearer, the embodiments of this application will be described below in conjunction with the drawings in the embodiments of this application.

[0062] The terms "first" and "second" in the specification, claims, and drawings of this application are used to distinguish different objects, not to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to the process, method, product, or device.

[0063] The “embodiment” mentioned herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It can be understood explicitly and implicitly by those skilled in the art that in the various embodiments of the present application, unless otherwise specified and there is a logical conflict, the terms and / or descriptions between the various embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form a new embodiment according to their inherent logical relationship.

[0064] It should be understood that in the present application, "at least one (item)" refers to one or more, "more than one" refers to two or more, "at least two (items)" refers to two or three and more than three, and "and / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0065] A communication and perception integrated system refers to a system that has both communication and perception functions. It can also be called a synaesthesia integrated system, such as a Wi-Fi radar integrated system. The synaesthesia integrated system can use a radar architecture to implement the perception function, that is, transmission and reception are turned on at the same time. For example, the chip is used to output a transmission signal, the antenna is used to transmit the transmission signal, and receive the target's echo signal (i.e., the received signal). The chip is also used to compare the received signal with the waveform of the transmission signal to obtain target information, thereby realizing the perception function.

[0066] As shown in Figure 1A, the synaesthesia system can adopt a dual-chip dual-antenna architecture, including two chips (chip 1 and chip 2) and two antennas (a transmitting antenna and a receiving antenna). Among them, chip 1 can be used as a transmitting chip to output a transmitting signal. The transmitting antenna is connected to chip 1 for transmitting a transmitting signal. The receiving antenna is used to receive a receiving signal. Chip 1 can be used as a receiving chip, connected to the receiving antenna, for receiving the receiving signal.

[0067] As shown in Figure 1B, the synaesthesia system can adopt a single-chip dual-antenna architecture, including a chip and two antennas (a transmitting antenna and a receiving antenna). The transmitting antenna and the receiving antenna are connected to the chip, and the chip is used to output the transmit signal, the transmitting antenna is used to transmit the transmit signal, and the receiving antenna is used to receive the receive signal. The chip is also used to receive the receive signal.

[0068] As shown in FIG1C , the synaesthesia system may adopt a single-chip single-antenna architecture, including a chip and an antenna, that is, the receiving antenna and the transmitting antenna are the same antenna, and signal reception and transmission are achieved through one antenna.

[0069] Exemplarily, the operating modes of the synaesthesia system may include a perception mode (or radar mode) and a communication mode. In radar mode, the synaesthesia system simultaneously receives and transmits signals via the antenna. The communication mode may include a communication reception mode and a communication transmission mode. In communication reception mode, the synaesthesia system receives signals via the antenna without transmitting any signals. In communication transmission mode, the synaesthesia system transmits signals via the antenna without receiving any signals. Exemplarily, the timings of the radar mode and communication mode of the synaesthesia system are different, that is, the communication and synaesthesia system has the characteristics of radar and communication operating at the same frequency but at different times, which can be called a time-division synaesthesia system. As shown in Figure 2, the synaesthesia system can determine the timing of the radar mode and the timing of the communication mode based on the actual usage scenario. Figure 2 shows a scenario in which the radar mode and communication mode alternate. The synaesthesia system can also continuously transmit communication frames or continuously transmit radar frames. It is understandable that the power of the signals in the radar mode and the communication mode can be the same or different.

[0070] In a system with a single antenna architecture, it is necessary to separate the forward and backward signals (i.e., the transmit signal and the receive signal) to achieve isolation between the transmit signal and the receive signal. For example, the system can use a circulator to achieve forward and backward signal separation. As shown in Figure 3, the transmit signal can be transmitted to the antenna array through a bias device, a coupler, and a circulator, and the antenna array transmits the transmit signal. After the antenna array receives the receive signal, it transmits the receive signal to the mixer through the circulator. The mixer mixes the receive signal with the transmit signal, thereby achieving separation between the transmit signal and the receive signal.

[0071] In the above-mentioned synaesthesia system, the signals received by the synaesthesia system include interference signals in addition to echoes, such as direct path interference signals that are directly received by the receiving antenna after being transmitted by the transmitting antenna, and coupled interference signals between the transmitting antenna and the receiving antenna feeder. In a system with a single-chip architecture, the interference signals also include coupled interference signals in the RF and IF parts of the chip and coupled interference signals between the chip pins. The above-mentioned interference signals are generated by the coupling of the transmitting signal and can also be called T-Rx path self-blocking signals. Generally, the interference signal is much larger than the receiving signal and is similar to the receiving signal, resulting in high difficulty in signal separation and serious interference to the detection of targets at longer distances and more precision. Moreover, in a system with a single antenna architecture, when a circulator is used to separate forward and backward signals, the circulator cannot be effectively miniaturized and built into the chip, which results in high cost. In addition, the isolation of the circulator is limited, and it cannot effectively separate the transmitting signal from the receiving signal.

[0072] In view of this, the embodiments of the present application provide an interference cancellation circuit and a parameter calibration method, which can reduce the interference of the interference signal on the received signal, facilitate the separation of the received signal, and facilitate the detection of targets at longer distances and with greater precision.

[0073] Please refer to Figure 4, which is a structural diagram of an interference cancellation circuit provided by an embodiment of the present application. The interference cancellation circuit can be applied to a synaesthesia system, or the interference cancellation circuit can also be applied to a single-antenna radar system. It is understandable that the description of the synaesthesia system can refer to the relevant description above, and will not be described in detail here. As shown in Figure 4, the interference cancellation circuit can be arranged between the chip and the antenna to eliminate the interference signal received by the receiving port of the chip. The interference cancellation circuit includes a first port, a second port and a transmitting feed module. Wherein, the first port is connected to the transmitting port of the chip, the second port is connected to the receiving port of the chip, and the transmitting feed module includes a third port and a fourth port, the third port is connected to the first port, and the fourth port is connected to the second port.

[0074] The first port is configured to receive a transmit signal from the transmit port of the chip. The transmit feed module is configured to amplitude modulate and / or phase shift the transmit signal to generate a first signal, and input the first signal to the second port via the fourth port. The second port is configured to output the first signal. The first signal is transmitted to the receive port of the chip to cancel interference signals at the receive port of the chip.

[0075] Exemplarily, the interference signal received by the chip's receive port is generated by coupling with the transmit signal, has the same frequency as the transmit signal, and may differ in amplitude and phase. For example, the interference signal includes at least one of the following: a chip transmit / receive coupled interference signal; and a direct path interference signal received by the antenna after the antenna transmits the signal. The chip transmit / receive coupled interference signal can also be referred to as a chip package coupled interference signal, including coupled interference signals within the chip's RF and IF sections, and coupled interference signals between chip pins.

[0076] The transmit feed module can generate a first signal by amplitude modulating or phase modulating the transmit signal, so that the first signal can cancel out the interference signal, that is, the power of the superimposed signal of the first signal and the interference signal is less than the power of the interference signal. For example, the first signal and the interference signal have opposite phases, and the amplitude of the first signal is less than or equal to the amplitude of the interference signal.

[0077] In an embodiment of the present application, the signal received by the receiving port of the chip includes a first signal, a received signal, and an interference signal. The received signal is the echo signal of the target received by the antenna. Since the interference signal is generated by coupling with the transmitted signal, it has the same frequency as the transmitted signal, but may have different amplitude and phase. Therefore, the transmitting feed module obtains a first signal that can offset the interference signal by amplitude modulating and / or phase modulating the transmitted signal, thereby reducing the interference of the interference signal on the received signal, which is beneficial to the separation of the received signal, so as to facilitate the detection of targets at longer distances and more precisely.

[0078] In one possible implementation, the transmitting feed module includes an attenuated phase shifting module and a directional coupling module. The attenuated phase shifting module and the directional coupling module are connected in series or in parallel. The attenuated phase shifting module is used to perform amplitude modulation and / or phase modulation on the transmitting signal. The directional coupling module is used to separate the transmitting signal from the receiving signal, that is, the directional coupling module is used to perform forward and backward signal separation.

[0079] Exemplarily, the directional coupling module can also be called a directional coupler or a directional coupling transmitting and feeding module. As shown in FIG5 , the directional coupling module may include two wires (respectively a first wire and a second wire) and four ports (respectively port 1, port 2, port 3 and port 4). Among them, port 1 and port 2 are on the first wire, and port 3 and port 4 are on the second wire. The length of the first wire and the second wire can be set to one quarter of the wavelength of the transmitted signal. The directional coupling module can achieve forward and backward separation of the signal through mutual coupling between the two wires, and achieve separation of the transmitted signal and the received signal, so that the chip can transmit and receive signals at the same time. Compared with the circulator, it is easier to miniaturize, thereby allowing the chip to be built-in, with lower production costs, and better separation of the transmitted signal and the received signal.

[0080] For example, as shown in FIG6 , the attenuation and phase shifting module includes an attenuator and a phase shifter, with the attenuator and the phase shifter connected in series. The attenuator is used to amplitude modulate the transmitted signal, and the phase shifter is used to phase modulate the transmitted signal. For example, the attenuator can be a digital attenuator or an analog attenuator. For example, the attenuator can include multiple resistors, including at least one variable resistor, so that the attenuation of the attenuator can be adjusted by adjusting the value of the variable resistor. FIG6 illustrates an attenuator including three resistors (including two variable resistors).

[0081] Exemplarily, the phase shifter may be a digital phase shifter or an analog phase shifter. For example, the phase shifter may include a variable capacitor, so that the phase shift of the phase shifter can be adjusted by changing the capacitance or voltage value of the variable capacitor.

[0082] It can be understood that the attenuator and phase shifter shown in Figure 6 are only examples. The attenuator and phase shifter in the embodiments of the present application may also include other electronic components. The resistor or capacitor structure shown in Figure 6 should not be understood as a limitation on the attenuator and phase shifter.

[0083] In one possible implementation, the above-mentioned attenuation phase shifting module is connected in series with the directional coupling module, as shown in Figure 4, and the directional coupling module includes a fifth port and a sixth port. The input port of the attenuation phase shifting module is connected to the third port, the output port of the attenuation phase shifting module is connected to the fifth port, and the fourth port is connected to the sixth port. The first port receives the transmission signal output by the transmitting port of the chip. After the attenuation phase shifting module receives the transmission signal through the third port, it modulates the transmission signal and / or shifts the phase to generate a second signal, and outputs the second signal to the directional coupling module. After the directional coupling module receives the second signal through the fifth port, it generates a first signal based on the second signal, and outputs the first signal to the fourth port through the sixth port. The fourth port outputs the first signal, and the first signal is transmitted from the fourth port to the second port and the receiving port of the chip.

[0084] Exemplarily, the power of the second signal is determined by the power of the transmitted signal and the attenuation of the attenuation phase shift module. For example, the power of the second signal, the power of the transmitted signal and the attenuation of the attenuation phase shift module satisfy the following formula: P2 = P0 - A

[0085] Where P0 is the power of the transmitted signal, P2 is the power of the second signal, and A is the attenuation of the attenuation phase shift module. P0 and P2 are in dBm, and A is in dB. For example, if the power of the transmitted signal P0 is 5.5 dBm and the attenuation A of the attenuation phase shift module is 4 dB, the power of the second signal P2 is 1.5 dBm.

[0086] In one possible implementation, the interference cancellation circuit further includes a seventh port, and the directional coupling module further includes an eighth port. The seventh port is connected to the antenna, and the eighth port is connected to the seventh port. The directional coupling module is further configured to generate a fifth signal based on the second signal, and output the fifth signal to the seventh port via the eighth port. The seventh port is configured to output the fifth signal, and the fifth signal is transmitted to the antenna, causing the antenna to transmit the fifth signal.

[0087] Exemplarily, in a directional coupling module, the fifth port is connected to a resistor (e.g., a 50-ohm resistor) and a reference ground via a wire (e.g., the first wire in FIG5 ), and the sixth and eighth ports are provided on the second wire. The fifth port is an input port for the second signal (e.g., port 1 in FIG5 ), the sixth port is an isolation port for the second signal (e.g., port 3 in FIG5 ), and the eighth port is a coupling port for the second signal (e.g., port 4 in FIG5 ). When the second signal is transmitted on the first wire, the first signal and the fifth signal are coupled on the second wire, and the first signal is output through the sixth port, and the fifth signal is output through the eighth port.

[0088] Exemplarily, the power of the fifth signal is determined by the power of the second signal and the coupling coefficient of the directional coupling module. The power of the fifth signal, the power of the second signal and the coupling coefficient of the directional coupling module satisfy the following formula: P5 = P2 - C1

[0089] Where C1 is the coupling coefficient of the directional coupling module, P2 is the power of the second signal, and P5 is the power of the fifth signal. For example, if P2 is 1.5 dBm and C1 is 10 dBc, then P5 is -8.5 dBm.

[0090] Exemplarily, the power of the first signal is determined by the power of the second signal and the isolation coefficient of the directional coupling module. For example, the power of the first signal, the power of the second signal and the isolation coefficient of the directional coupling module satisfy the following formula: P1 = P2 - I

[0091] Where I is the isolation coefficient, P1 is the power of the first signal, and P2 is the power of the second signal. For example, if P1 is 1.5dBm and I is 20dBc, then P1 is -18.5dBm.

[0092] The power of the second signal is determined by the power of the transmitted signal and the attenuation of the attenuation phase shift module. Therefore, the power of the first signal is determined by the power of the transmitted signal, the attenuation of the attenuation phase shift module, and the isolation coefficient of the directional coupling module. For example, the power of the first signal and the power of the transmitted signal satisfy the following formula: P1 = P0 - AI

[0093] Wherein, P1 is the power of the first signal, P0 is the power of the transmitted signal, A is the attenuation of the attenuation phase shift module, and I is the isolation coefficient of the directional coupling module.

[0094] Exemplarily, the isolation coefficient of the directional coupling module is determined by the self-coupling coefficient of the chip. The interference signal includes the transmit-receive coupled interference signal of the chip, and the power of the transmit-receive coupled interference signal is determined by the self-coupling coefficient of the chip (or can be called the chip package coupling coefficient). For example, the power of the transmit-receive coupled interference signal, the power of the transmit signal, and the self-coupling coefficient of the chip satisfy the following formula: Ppac = P0 - Cpac

[0095] Where Ppac is the power of the transmitted / received coupled interference signal, P0 is the power of the transmitted signal, and Cpac is the chip's self-coupling coefficient. For example, if P0 is 5.5dBm and Cpac is 29dBc, then Ppac is -23.5dBm.

[0096] Exemplarily, the isolation coefficient of the directional coupling module is greater than or equal to the self-coupling coefficient of the chip. For example, the difference between the isolation coefficient of the directional coupling module and the self-coupling coefficient of the chip is less than or equal to a second threshold. In other words, the isolation coefficient of the directional coupling module may be slightly greater than the self-coupling coefficient of the chip.

[0097] As can be seen from the above, when the isolation coefficient of the directional coupling module is close to the chip's self-coupling coefficient and slightly greater than the chip's self-coupling coefficient, the attenuation phase shifting module can amplitude modulate the transmitted signal with a small attenuation, allowing the first signal to cancel out the chip's transmit / receive coupled interference signal and reducing the loss of the transmitted signal in the attenuation phase shifting module. Furthermore, when the isolation coefficient of the directional coupling module is slightly greater than the chip's self-coupling coefficient, the power of the generated first signal is less than that of the interference signal, thereby avoiding additional interference caused by the first signal's excessive power.

[0098] In one possible implementation, the seventh port is also used to receive a received signal from the antenna and output the received signal to the eighth port, where the received signal is the signal received by the antenna; the directional coupling module is also used to receive the received signal through the eighth port and output the received signal to the fourth port through the sixth port; and the fourth port is also used to output the received signal.

[0099] Exemplarily, the received signal is an echo signal of a target received by the antenna. For example, the received signal can be an echo signal of the fifth signal reflected by the target after the antenna transmits the fifth signal. That is, after the antenna receives the received signal, it can transmit the received signal to the seventh port, and the seventh port then transmits the received signal to the eighth port. After the directional coupling module receives the received signal through the eighth port, it transmits the received signal to the fourth port through the sixth port, and the fourth port then transmits the received signal to the second port, and the second port outputs the received signal to the receiving port of the chip. Since the eighth port and the sixth port are arranged on the same wire, the eighth port is equivalent to the incident port of the received signal, and the sixth port is equivalent to the through port of the received signal. Therefore, the received signal can be directly transmitted from the eighth port to the sixth port, thereby isolating the transmit signal and the receive signal through the directional coupling module, and realizing the simultaneous opening of transmission and reception.

[0100] In one possible implementation, the interference elimination circuit may further include a matching module. As shown in FIG7 , the matching module is disposed between the eighth port and the seventh port of the directional coupling module, that is, the eighth port is connected to the seventh port through the matching module. The matching module includes a ninth port and a tenth port, the ninth port is connected to the eighth port, and the tenth port is connected to the seventh port. The matching module is configured to receive the fifth signal through the ninth port, output a reflected signal through the ninth port, and output the fifth signal to the seventh port through the tenth port. The directional coupling module is further configured to output the reflected signal to the fourth port through the sixth port; the fourth port is further configured to output a reflected signal, and the reflected signal is configured to offset the interference signal.

[0101] Exemplarily, the matching module can also be used to perform impedance matching to achieve matching between the antenna and the transmission line to ensure signal gain. After the fifth signal output from the eighth port of the directional coupling module is transmitted to the ninth port, it is transmitted at the ninth port to generate a reflected signal. The reflected signal is transmitted from the ninth port to the eighth port, output from the sixth port after passing through the directional coupling module, and transmitted to the receiving port of the chip through the fourth port and the second port.

[0102] Exemplarily, the frequency of the reflected signal is the same as the frequency of the fifth signal, and the amplitude and phase of the reflected signal and the fifth signal may be the same or different. The power of the reflected signal is determined by the reflection coefficient of the ninth port. For example, the power of the reflected signal and the reflection coefficient of the ninth port satisfy the following formula: Pre = P5 + S11

[0103] Where Pre is the power of the reflected signal, S11 is the reflection coefficient of the ninth port, and P5 is the power of the fifth signal. For example, if the power of the fifth signal is -8.5 dBm and S11 is -10 dB, then the power Pre of the reflected signal is -18.5 dBm.

[0104] Exemplarily, the matching module may include at least one variable capacitor or at least one variable resistor, and the at least one variable capacitor or at least one variable resistor is used to adjust the phase of the reflected signal. For example, as shown in FIG7 , the matching module may include three variable capacitors, which form a π-type matching network. The phase of the reflected signal can be changed by changing the capacitance value of any of the three variable capacitors.

[0105] In the embodiment of the present application, the matching module can also be replaced by the description of "dynamic matching network", "matching network", etc. This application does not limit the name of the matching module.

[0106] In the embodiments of the present application, the reflected signal and the first signal can be used to offset the interference signal, thereby better eliminating interference. Furthermore, by changing the value of at least one variable capacitor or at least one variable resistor in the matching module to adjust the phase of the reflected signal, the reflected signal can better offset the interference signal, thereby avoiding interference caused by the reflected signal.

[0107] Please refer to Figure 8A, which is a schematic diagram of the structure of another interference cancellation circuit provided in an embodiment of the present application. As shown in Figure 8A, the interference cancellation circuit includes a first port, a second port, a transmit feed module, a first switch, and a second switch. The transmit feed module includes an attenuated phase shift module and a directional coupling module. The attenuated phase shift module includes a fifth port and a sixth port. The first switch includes a first fixed terminal, a first movable terminal, and a second movable terminal. The second switch includes a second fixed terminal, a third movable terminal, and a fourth movable terminal.

[0108] The first port is connected to the chip's transmit port, the second port is connected to the chip's receive port. The transmit feed module includes a third port and a fourth port. The input port of the attenuation and phase shifting module is connected to the third port, the output port of the attenuation and phase shifting module is connected to the fifth port, and the fourth port is connected to the sixth port. The first fixed terminal is connected to the third port, the first movable terminal is connected to the first port, and the second movable terminal is connected to the reference ground. The second fixed terminal is connected to the fourth port, the third movable terminal is connected to the second port, and the fourth movable terminal is connected to the first port.

[0109] Exemplarily, the second moving end may be connected to the reference ground via a resistor (eg, a 50-ohm resistor).

[0110] As shown in Figure 8A, with the first fixed terminal connected to the first moving terminal and the second fixed terminal connected to the third moving terminal, the path between the attenuation and phase shifting module and the first port is opened by the first switch, and the path between the directional coupling module and the second port is opened by the second switch. In this case, the chip can be in sensing mode or radar mode, simultaneously receiving and transmitting signals to realize the chip's sensing function. It is understood that the signal flow in this case can be referred to the relevant description of the circuit shown in Figure 4 and will not be detailed here.

[0111] As shown in Figure 8B, when the first fixed terminal is connected to the second movable terminal, and the second fixed terminal is connected to the third movable terminal, the directional coupling module is used to transmit a received signal to the second port, and the second port is used to output the received signal. The received signal is a signal received from the antenna at the seventh port. In this case, the path between the directional coupling module and the chip's receive port is connected by the second switch, and the chip is in communication receive mode. After the antenna receives the receive signal, the receive signal can be transmitted to the chip's receive port via the seventh port, the eighth port, the sixth port, the fourth port, the second switch, and the second port.

[0112] As shown in Figure 8C , when the first fixed terminal is connected to the second movable terminal, and the second fixed terminal is connected to the fourth movable terminal, the directional coupling module is used to transmit a transmit signal to the seventh port. In this case, the second switch conducts the path between the directional coupling module and the chip's transmit port. The chip operates in communication transmit mode. After the chip's transmit port outputs a transmit signal, the transmit signal is transmitted through the second switch, the fourth port, the sixth port, and the eighth port to the seventh port. The seventh port then transmits the transmit signal to the antenna, causing the antenna to transmit the transmit signal.

[0113] In an embodiment of the present application, when the chip is in a communication transmission module or a receiving mode, the path between the chip's transmitting port and the attenuation phase shift module is disconnected by a first switch, so that the chip is not affected by the attenuation phase shift module in the communication transmission mode or the communication receiving mode, thereby ensuring the stability of the chip's communication performance.

[0114] In one possible implementation, the interference cancellation circuits shown in Figures 8A, 8B, and 8C further include a matching module for impedance matching to achieve impedance matching between the antenna and the transmission line, thereby ensuring signal gain. It is understood that a detailed description of this matching module can be found in the relevant description of the circuit shown in Figure 6 and will not be detailed here.

[0115] Please refer to Figure 9, which is a structural diagram of another interference elimination circuit provided in an embodiment of the present application. As shown in Figure 9, the interference elimination circuit includes a first port, a second port, and a transmitting feed module. Among them, the transmitting feed module includes an attenuation phase shifting module, a directional coupling module, a third port and a fourth port, and the directional coupling module includes a fifth port and a sixth port. The first port is connected to the transmitting port of the chip, the second port is connected to the receiving port of the chip, the third port is connected to the first port, the fourth port is connected to the second port, the input port of the attenuation phase shifting module is connected to the third port, the output port of the attenuation phase shifting module is connected to the fourth port, the fifth port is connected to the third port, and the sixth port is connected to the fourth port.

[0116] The first port is used to receive a transmit signal from the chip's transmit port. The attenuation and phase shifting module is used to amplitude modulate and / or phase shift the transmit signal to generate a third signal, and transmit the third signal to the fourth port. The directional coupling module is used to generate a fourth signal based on the transmit signal and transmit the fourth signal to the fourth port. The fourth port is used to output the first signal, which is composed of the third signal and the fourth signal, that is, the first signal is a superposition signal of the third signal and the fourth signal.

[0117] It is understandable that for the description of the directional coupling module and the attenuated phase shift module, reference may be made to the relevant descriptions in FIG5 and FIG6 above, and they will not be described in detail here.

[0118] Exemplarily, the isolation coefficient of the directional coupling module may be determined by the self-coupling coefficient of the chip.

[0119] Exemplarily, the power of the third signal is determined by the power of the transmitted signal and the attenuation of the attenuation phase shift module. For example, the power of the third signal, the power of the transmitted signal and the attenuation of the attenuation phase shift module satisfy the following formula: P3 = P0 - A

[0120] Wherein, P0 is the power of the transmitted signal, P3 is the power of the third signal, and A is the attenuation of the attenuation phase shift module.

[0121] Exemplarily, the power of the fourth signal is determined by the power of the transmitted signal and the isolation coefficient of the directional coupling module. For example, the power of the fourth signal, the power of the transmitted signal and the isolation coefficient of the directional coupling module satisfy the following formula: P4 = P0 - I

[0122] Wherein, I is the isolation coefficient of the directional coupling module, P4 is the power of the fourth signal, and P0 is the power of the transmitted signal.

[0123] In one possible implementation, the interference cancellation circuit shown in FIG9 further includes a seventh port, and the directional coupling module further includes an eighth port; the seventh port is connected to the antenna, and the eighth port is connected to the seventh port. The directional coupling module is further configured to generate a fifth signal based on the transmit signal and output the fifth signal to the seventh port via the eighth port. The seventh port is configured to output the fifth signal, which is transmitted to the antenna so that the antenna transmits the fifth signal.

[0124] Exemplarily, in the directional coupling module, the eighth port and the sixth port are provided on the same conductor (such as the second conductor in FIG. 5 ), and the fifth port is provided on another conductor (such as the first conductor in FIG. 5 ). The directional coupling module receives a transmit signal through the fifth port. When the transmit signal is transmitted on the first conductor, the first conductor couples with the second conductor, thereby generating a fourth signal and a fifth signal on the second conductor. The fourth signal is output through the sixth port, and the fifth signal is output through the eighth port.

[0125] Exemplarily, the power of the fifth signal is determined by the power of the transmitted signal and the coupling coefficient of the directional coupling module. The power of the fifth signal, the power of the transmitted signal and the coupling coefficient of the directional coupling module satisfy the following formula: P5 = P0 - C1

[0126] Where C1 is the coupling coefficient of the directional coupling module, P0 is the power of the transmitted signal, and P5 is the power of the fifth signal. For example, if P0 is 5.5 dBm and C1 is 10 dBc, then P5 is -4.5 dBm.

[0127] It is understood that the transmit signal may experience loss in the attenuation and phase shifting module, so the power of the transmit signal received by the fifth port may differ from the power of the transmit signal output by the chip's transmit port. For example, if the transmit signal experiences 1 dB of loss in the attenuation and phase shifting module, and the transmit signal power output by the transmit port is 5.5 dBm, the transmit signal power received by the fifth port will be 4.5 dBm.

[0128] In one possible implementation, the seventh port is also used to receive a received signal from the antenna and output the received signal to the eighth port, where the received signal is the signal received by the antenna; the directional coupling module is also used to receive the received signal through the eighth port and output the received signal to the fourth port through the sixth port; and the fourth port is also used to output the received signal.

[0129] In one possible implementation, the interference elimination circuit may further include a matching module. As shown in FIG10 , the matching module is disposed between the eighth port and the seventh port of the directional coupling module, that is, the eighth port is connected to the seventh port through the matching module. The matching module includes a ninth port and a tenth port, the ninth port is connected to the eighth port, and the tenth port is connected to the seventh port. The matching module is configured to receive the fifth signal through the ninth port, output a reflected signal through the ninth port, and output the fifth signal to the seventh port through the tenth port. The directional coupling module is further configured to output the reflected signal to the fourth port through the sixth port; the fourth port is further configured to output a reflected signal, and the reflected signal is configured to offset the interference signal.

[0130] It is understandable that for the specific description of the matching module, reference can be made to the relevant description of the circuit shown in FIG7 , which will not be described in detail here.

[0131] In an embodiment of the present application, the interference cancellation circuit may include multiple attenuation phase-shifting modules, which are connected in parallel to perform amplitude modulation and / or phase modulation on the transmitted signal to generate a signal for canceling the interference signal. The attenuation phase-shifting module in the circuit shown in FIG9 may also be connected in parallel to one or more attenuation phase-shifting modules.

[0132] In an embodiment of the present application, an attenuated phase shifting module is connected in parallel with a directional coupling module to generate a third signal and a fourth signal based on the transmitted signal, respectively. The amplitude and phase of the third signal and the fourth signal may be the same or different. Since the interference signal may be composed of signals with different amplitudes and phases, the attenuated phase shifting module and the directional coupling module can generate signals with different amplitudes and phases, thereby enabling the first signal to better offset the interference signal. Moreover, the signal generated by the isolation port when the directional coupler transmits the transmitted signal can be reasonably used to offset the interference signal, thereby making the interference cancellation operation simpler.

[0133] Please refer to Figure 11A, which is a schematic diagram of the structure of another interference cancellation circuit provided in an embodiment of the present application. As shown in Figure 11A, the interference cancellation circuit includes a first port, a second port, a transmit feed module, a first switch, and a second switch. The transmit feed module includes an attenuated phase shift module and a directional coupling module. The attenuated phase shift module includes a fifth port and a sixth port. The first switch includes a first fixed terminal, a first movable terminal, and a second movable terminal. The second switch includes a second fixed terminal, a third movable terminal, and a fourth movable terminal.

[0134] The first port is connected to the chip's transmit port, the second port is connected to the chip's receive port, the transmit feed module includes a third port and a fourth port, the input port of the attenuation and phase shifting module is connected to the third port, the output port of the attenuation and phase shifting module is connected to the fourth port, the fifth port is connected to the third port, and the sixth port is connected to the fourth port. The first fixed terminal is connected to the third port, the first movable terminal is connected to the first port, and the second movable terminal is connected to the reference ground. The second fixed terminal is connected to the fourth port, the third movable terminal is connected to the second port, and the fourth movable terminal is connected to the first port.

[0135] Exemplarily, the second moving end may be connected to the reference ground via a resistor (eg, a 50-ohm resistor).

[0136] As shown in Figure 11A, with the first fixed terminal connected to the first moving terminal and the second fixed terminal connected to the third moving terminal, the path between the attenuation and phase shifting module and the first port is opened by the first switch, and the path between the directional coupling module and the second port is opened by the second switch. In this case, the chip can be in sensing mode or radar mode, simultaneously receiving and transmitting signals to realize the chip's sensing function. It is understood that the signal flow in this case can be referred to the relevant description of the circuit shown in Figure 9 and will not be detailed here.

[0137] As shown in Figure 11B, when the first fixed terminal is connected to the second movable terminal, and the second fixed terminal is connected to the third movable terminal, the directional coupling module is used to transmit a received signal to the second port, and the second port is used to output the received signal. The received signal is a signal received from the antenna at the seventh port. In this case, the path between the directional coupling module and the chip's receive port is connected by the second switch, and the chip is in communication receive mode. After the antenna receives the receive signal, the receive signal can be transmitted to the chip's receive port via the seventh port, the eighth port, the sixth port, the fourth port, the second switch, and the second port.

[0138] As shown in Figure 11C, when the first fixed terminal is connected to the second movable terminal, and the second fixed terminal is connected to the fourth movable terminal, the directional coupling module is used to transmit a transmit signal to the seventh port. In this case, the second switch conducts the path between the directional coupling module and the chip's transmit port. The chip operates in communication transmit mode. After the chip's transmit port outputs a transmit signal, the transmit signal is transmitted through the second switch, the fourth port, the sixth port, and the eighth port to the seventh port. The seventh port then transmits the transmit signal to the antenna, causing the antenna to transmit the transmit signal.

[0139] In an embodiment of the present application, when the chip is in a communication transmission module or a receiving mode, the path between the chip's transmitting port and the attenuation phase shift module is disconnected by a first switch, so that the chip is not affected by the attenuation phase shift module in the communication transmission mode or the communication receiving mode, thereby ensuring the stability of the chip's communication performance.

[0140] In one possible implementation, the interference cancellation circuit shown in Figures 11A, 11B, and 11C further includes a matching module for impedance matching to achieve impedance matching between the antenna and the transmission line, thereby ensuring signal gain. It is understood that a detailed description of the matching module can be found in the relevant description of the circuit shown in Figure 7 and will not be detailed here.

[0141] In the embodiments of the present application, the chip may be a WiFi chip or an ultra-wideband (UWB) chip, or other chips with wireless communication capabilities. That is, the circuits shown in Figures 4, 7, 8A, 8B, 8C, 9, 10, 11A, 11B, and 11C may be applied to a WiFi-based telepathic system or a UWB system or other wireless communication systems (e.g., a Bluetooth (BT) system or a Bluetooth Low Energy (BLE) system).

[0142] In the embodiment of the present application, the chip can be replaced with an unpackaged integrated circuit (i.e., a bare die or bare chip) with wireless communication functionality, and the interference cancellation circuit shown in Figures 4, 7, and 11C can be packaged in the same chip as the integrated circuit. Alternatively, the interference cancellation circuit shown in Figures 3, 6, and 11C can be packaged in a single chip.

[0143] Please refer to Figure 12, which is a schematic flow chart of a parameter calibration method provided in an embodiment of the present application. This method can be applied to a controller connected to an interference cancellation circuit, which is used to eliminate interference signals from the chip. The description of the interference cancellation circuit can be found in Figures 4 and 7-11C, and will not be detailed here. As shown in Figure 12, the method includes but is not limited to the following steps.

[0144] 1201. Obtain a first gradient value of a first parameter, where the first gradient value is used to indicate the degree of influence of the first parameter on the power of an interference signal. The first parameter is a parameter in an interference cancellation circuit.

[0145] Exemplarily, the interference signal may also be referred to as a direct path interference signal, and the interference signal is a signal other than the received signal in the chip receiving port.

[0146] Exemplarily, the first parameter is an adjustable parameter in the interference cancellation circuit. For example, the interference cancellation circuit includes an attenuation phase shift module and a matching module. The first parameter may include any one of the attenuation amount of the attenuation phase shift module, the phase shift amount of the attenuation phase shift module, and the phase shift amount of the matching module.

[0147] Exemplarily, the attenuation and phase shift of the attenuated phase shift module are determined by the parameters of the electronic components in the attenuated phase shift module, and the phase shift of the matching module is determined by the electronic components in the matching module. Therefore, the first parameter may include the parameters of the electronic components in the attenuated phase shift module and the matching module. For example, the attenuated phase shift module includes an attenuator and a phase shifter, the attenuator includes at least one variable resistor, the phase shifter includes a variable capacitor, and the matching module includes at least one variable capacitor or at least one variable resistor. The first parameter may include the resistance value of the variable resistor in the attenuator, the capacitance value of the variable capacitor in the phase shifter, the capacitance value of the variable capacitor in the matching module, or the resistance value of the variable resistor in the matching module.

[0148] Exemplarily, the controller may be packaged in the chip, or the controller may not be packaged in the chip. It is understood that when the controller is packaged in the chip, the chip adjusts the parameters of the interference cancellation circuit according to the first gradient value to reduce the interference it receives.

[0149] In one possible implementation, the controller obtaining the first gradient value of the first parameter may include the following steps: when the first parameter is a first value, the control chip outputs a first transmission signal, and obtains a first power value of the interference signal corresponding to the first transmission signal; when the first parameter is a second value, the control chip outputs a second transmission signal, and obtains a second power value of the interference signal corresponding to the second transmission signal; and determines the first gradient value based on the first value, the second value, the first power value, and the second power value.

[0150] As an example, when the controller obtains the power value of the interference signal corresponding to the transmitted signal, it can separate the interference signal and the received signal from the signal received by the chip's receive port to obtain the power value of the interference signal. For example, the received signal and the interference signal can be obtained through fast time compression, that is, using the waveform of the transmitted signal as a sample and performing matched filtering on the received waveform to obtain the received signal.

[0151] As another example, the interference cancellation circuit is provided between the chip and a reference ground, i.e., the seventh port of the interference cancellation circuit shown above is connected to the reference ground. In this example, the signal received by the chip's receiving port is the interference signal, and the controller can directly obtain the interference signal from the receiving port without separating the received signal.

[0152] Exemplarily, after obtaining the first value, the second value, the first power value, and the second power value, the controller can determine a first difference and a second difference, where the first difference is the difference between the first value and the second value, and the second difference is the difference between the first power value and the second power value. The first gradient value can be represented by the ratio of the first difference and the second difference. For example, when the attenuation of the attenuation phase shift module is 5dB, the power value of the interference signal is 10dBm, and when the attenuation of the attenuation phase shift module is 4dB, the power value of the interference signal is 5dBm. The gradient value corresponding to the attenuation of the attenuation phase shift module can be expressed as 0.2.

[0153] It can be understood that the controller can control the chip to output the transmission signal multiple times, so as to obtain multiple first parameter values ​​and multiple power values, and then use the average value of the multiple first parameter values ​​and the average value of the multiple power values ​​to obtain the first gradient value, or use the multiple first parameter values ​​and multiple power values ​​to calculate multiple gradient values, and the first gradient value is the average value of the multiple gradient values.

[0154] Exemplarily, when the first parameter includes multiple parameters, the first gradient value includes gradient values ​​corresponding to the multiple parameters. The controller can obtain the gradient values ​​corresponding to the multiple parameters respectively. For example, the controller adjusts the value of one parameter each time, while keeping the values ​​of the other parameters unchanged, and controls the chip to output a transmit signal to obtain the gradient value corresponding to the parameter.

[0155] In the embodiment of the present application, by obtaining the value of the adjusted first parameter and respectively obtaining the power values ​​of the interference signal when the first parameter takes different values, the influence of the first parameter on the power of the interference signal can be accurately obtained.

[0156] 1202. Adjust the value of the first parameter according to the first gradient value until the power of the interference signal meets the first condition.

[0157] Exemplarily, the controller gradually adjusts the first parameter according to a first gradient value to gradually reduce the power of the interference signal until the power of the interference signal satisfies the first condition. Each time the controller adjusts the value of the first parameter according to the first gradient value, the control chip outputs a transmit signal to obtain the power of the interference signal corresponding to the current value of the first parameter.

[0158] As an example, the first condition may include that the power of the interference signal is less than a first threshold. The first threshold may be determined based on the business requirements or capabilities of the chip. For example, the higher the interference requirements of the chip's business, the smaller the value of the first threshold. For another example, the chip can separate the interference signal and the received signal when the power of the interference signal is less than the first threshold. In this example, by adjusting the value of the first parameter, the power of the interference signal of the chip is less than the first threshold, so that the interference of the chip can meet the requirements, for example, the chip can separate the interference signal from the received signal.

[0159] As another example, the first condition includes that the power of the interference signal has no downward trend, or the power of the interference signal has an upward trend. That is, each time the controller obtains the power of the interference signal, the power of the interference signal obtained this time is compared with the power of the interference signal obtained last time. If the power of the interference signal remains unchanged or the power of the interference signal does not change for several consecutive times, the controller no longer adjusts the power of the first parameter. Alternatively, when the power of the interference signal obtained this time is greater than the power of the interference signal obtained last time, the controller no longer adjusts the power of the first parameter and records the value of the first parameter corresponding to the power of the interference signal obtained last time. That is, after comparing the power of the interference signal obtained many times, when the power of the interference signal has no downward trend, or when the power of the interference signal has an upward trend, stop adjusting the first parameter, so that the power of the interference signal is relatively small.

[0160] Exemplarily, when the first parameter includes multiple parameters, the values ​​of each parameter are adjusted according to the corresponding gradient value. For example, if the gradient value corresponding to the attenuation of the attenuation phase shifting module is 0.2, and the gradient value corresponding to the phase shift of the attenuation phase shifting module is 0.3, then each time the parameters are adjusted, the attenuation of the attenuation phase shifting module is adjusted by 0.2 dB, and the phase shift of the attenuation phase shifting module is adjusted by 0.3 degrees.

[0161] Exemplarily, after the power of the interference signal meets the first condition, the controller saves the value of the first parameter so that the value of the first parameter can be used in the subsequent process of the chip receiving the transmit signal to make the interference signal of the chip meet the first condition without repeating the calibration and adjustment of the parameters.

[0162] In an embodiment of the present application, the controller gradually adjusts the parameters in the interference cancellation circuit according to the first gradient value to gradually reduce the power of the interference signal until the power of the interference signal can meet the first condition, so that the interference cancellation circuit can better eliminate the interference signal of the chip.

[0163] In an embodiment of the present application, the controller can be a chip or a processor, including a logic circuit and an interface, the interface is used to receive relevant information (for example, a first gradient value, the power of the interference signal) and output control instructions, the control instructions are used to adjust the value of the first parameter and control the chip to output a transmission signal; the logic circuit can be used to execute related logic control processes, such as determining whether the power of the interference signal meets the first condition, confirming the value of the first parameter, etc.

[0164] An embodiment of the present application also provides a chip, which may include a packaging substrate and a bare chip (die). The bare chip is provided with a circuit as shown in any of Figures 4, 7 to 11C, and the packaging substrate can be used to package the bare chip.

[0165] An embodiment of the present application also provides a wireless transceiver system, which may include a chip, an antenna, and an interference cancellation circuit. The interference cancellation circuit may be a circuit as shown in any one of Figures 4, 7-11C.

[0166] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. An interference elimination circuit, characterized in that: Applied to the synaesthesia system, comprising a first port, a second port, and a transmitting and feeding module; The first port is connected to the transmitting port of the chip, the second port is connected to the receiving port of the chip, the transmitting feed module includes a third port and a fourth port, the third port is connected to the first port, and the fourth port is connected to the second port; The first port is used to receive a transmission signal from a transmission port of the chip; a transmitting feeding module, configured to perform amplitude modulation and / or phase shifting on the transmitting signal to generate a first signal, and input the first signal to the second port through the fourth port; The second port is used to output the first signal; wherein the first signal is transmitted to the receiving port of the chip to offset the interference signal of the receiving port of the chip.

2. The circuit according to claim 1, characterized in that The transmitting feeding module includes an attenuation phase shifting module and a directional coupling module, and the directional coupling module includes a fifth port and a sixth port; The input port of the attenuated phase shift module is connected to the third port, the output port of the attenuated phase shift module is connected to the fifth port, and the fourth port is connected to the sixth port; The attenuation phase shift module is used to perform amplitude modulation and / or phase shift on the transmission signal to generate a second signal, and output the second signal to the directional coupling module; The directional coupling module is used to generate the first signal according to the second signal, and output the first signal to the fourth port through the sixth port.

3. The circuit according to claim 1, characterized in that The transmitting feeding module includes an attenuation phase shifting module and a directional coupling module, and the directional coupling module includes a fifth port and a sixth port; The input port of the attenuated phase shift module is connected to the third port, the output port of the attenuated phase shift module is connected to the fourth port, the fifth port is connected to the third port, and the sixth port is connected to the fourth port; The attenuation phase shifting module is used to perform amplitude modulation and / or phase shifting on the transmission signal to generate a third signal, and transmit the third signal to the fourth port; The directional coupling module is used to generate a fourth signal based on the transmission signal, and transmit the fourth signal to the fourth port; The fourth port is used to output the first signal, where the first signal is composed of the third signal and the fourth signal.

4. The circuit according to claim 2 or 3, characterized in that The circuit further includes a seventh port, and the directional coupling module further includes an eighth port; the seventh port is connected to the antenna, and the eighth port is connected to the seventh port; The directional coupling module is further used to generate a fifth signal according to the second signal or the transmission signal, and output the fifth signal to the seventh port through the eighth port; The seventh port is used to output the fifth signal, and the fifth signal is transmitted to the antenna.

5. The circuit according to claim 4, characterized in that The circuit further includes a matching module, the eighth port is connected to the seventh port through the matching module, the matching module includes a ninth port and a tenth port, the ninth port is connected to the eighth port, and the tenth port is connected to the seventh port; The matching module is configured to receive the fifth signal through the ninth port, output a reflected signal through the ninth port, and output the fifth signal to the seventh port through the tenth port; The directional coupling module is further used to output the reflected signal to the fourth port through the sixth port; The fourth port is further used to output the reflected signal, and the reflected signal is used to offset the interference signal.

6. The circuit according to claim 5, characterized in that The matching module includes at least one variable capacitor or at least one variable resistor, and the at least one variable capacitor or at least one variable resistor is used to adjust the phase of the reflected signal.

7. The circuit according to claim 5 or 6, characterized in that The power of the reflected signal is determined by the reflection coefficient of the ninth port of the matching module.

8. The circuit according to any one of claims 4 to 7, characterized in that: The seventh port is further used to receive a reception signal from the antenna and output the reception signal to the eighth port, wherein the reception signal is a signal received by the antenna; The directional coupling module is further configured to receive the received signal through the eighth port, and output the received signal to the fourth port through the sixth port; The fourth port is also used to output the received signal.

9. The circuit according to any one of claims 4 to 8, characterized in that: The circuit further includes a first switch and a second switch, the first switch includes a first fixed end, a first movable end and a second movable end, and the second switch includes a second fixed end, a third movable end and a fourth movable end; The first fixed end is connected to the third port, the first movable end is connected to the first port, and the second movable end is connected to the reference ground; the second fixed end is connected to the fourth port, the third movable end is connected to the second port, and the fourth movable end is connected to the first port; The directional coupling module is also used to transmit a receiving signal to the second port when the first fixed end is connected to the second moving end and the second fixed end is connected to the third moving end, and the second port is used to output the receiving signal; wherein the receiving signal is a signal received by the seventh port from the antenna; or, The directional coupling module is further configured to transmit the transmission signal to the seventh port when the first fixed end is connected to the second movable end, and the second fixed end is connected to the fourth movable end.

10. The circuit according to any one of claims 4 to 9, characterized in that: The power of the fifth signal is determined by the power of the second signal or the transmit signal and the coupling coefficient of the directional coupling module.

11. The circuit according to any one of claims 2 to 10, characterized in that: The isolation coefficient of the directional coupling module is determined by the self-coupling coefficient of the chip.

12. The circuit according to any one of claims 2 to 11, characterized in that: The attenuation and phase shifting module comprises an attenuator and a phase shifter. The attenuator and the phase shifter are connected in series. The attenuator is used to perform amplitude modulation on the transmission signal, and the phase shifter is used to perform phase modulation on the transmission signal.

13. The circuit according to any one of claims 2 to 12, characterized in that: The power of the first signal is determined by the power of the transmit signal and the isolation coefficient of the directional coupling module.

14. The circuit according to any one of claims 1 to 13, characterized in that: The interference signal includes at least one of the following: a transmission-reception coupling interference signal of the chip, and a direct path interference signal received by the antenna after the antenna transmits the signal.

15. A parameter calibration method, characterized in that: Applied to a controller, the controller is connected to an interference elimination circuit, the interference elimination circuit is used to eliminate interference signals of a chip, and the method includes: Acquire a first gradient value of a first parameter, where the first gradient value is used to indicate the degree of influence of the first parameter on the power of the interference signal, and the first parameter is a parameter in the interference elimination circuit; The value of the first parameter is adjusted according to the first gradient value until the power of the interference signal meets a first condition.

16. The method according to claim 15, characterized in that The first condition includes that the power of the interference signal is less than a first threshold.

17. The method according to claim 15 or 16, characterized in that The obtaining of a first gradient value of a first parameter comprises: When the first parameter is a first value, controlling the chip to output a first transmit signal, and obtaining a first power value of an interference signal corresponding to the first transmit signal; When the first parameter is a second value, controlling the chip to output a second transmit signal, and obtaining a second power value of an interference signal corresponding to the second transmit signal; The first gradient value is determined based on the first value, the second value, the first power value, and the second power value.

18. The method according to any one of claims 15 to 17, characterized in that: The interference elimination circuit includes at least one of an attenuation phase shift module, a directional coupling module, and a matching module, and the first parameter includes at least one of the following: the attenuation amount of the attenuation phase shift module, the phase shift amount of the attenuation phase shift module, and the phase shift amount of the matching module.

19. The method according to any one of claims 15 to 18, characterized in that: The method further comprises: The value of the first parameter is saved.

20. A chip, characterized in that: The chip includes a packaging substrate and a bare chip, the bare chip is provided with the interference elimination circuit according to any one of claims 1 to 14, and the packaging substrate is used to package the bare chip.

21. A wireless transceiver system, characterized in that: The wireless transceiver comprises a chip, an antenna and an interference elimination circuit as described in any one of claims 1-14.

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