Antenna tuning device and method

Abstract

The present application provides an antenna tuning device and method, which relates to the field of communication technology and is used to reduce the storage overhead and tuning delay in the antenna tuning process. The device includes: an impedance tuning circuit coupled to an antenna, used to provide impedance matching, the impedance tuning circuit having a reference state, the reference state being a preset state among a plurality of impedance tuning circuit states, the reference state being used to measure the state parameters of the antenna; an interface circuit, used to receive a first control signal, the first control signal being used to put the impedance tuning circuit in the reference state.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to an antenna tuning device and method. Background Art

[0002] Among them, the terminal antenna is a device for converting electric energy into electromagnetic energy. Its impedance will also change in different operating frequencies and different usage scenarios (for example, the antenna is located at any position, held in the hand, or close to the head during a call). In addition, when the terminal transmits high-frequency signals through the antenna, in order to efficiently transmit the RF signal to the antenna or to the low-noise amplifier of the RF front end, it is necessary to ensure that the source impedance and the load impedance meet or are close to the power matching condition, that is, the source impedance and the load impedance are conjugate and equal. If the source impedance and the load impedance are mismatched, it will lead to problems such as increased power consumption of the terminal, reduced battery life, and dropped calls, which will reduce the user experience.

[0003] Antenna tuning technology can be used to solve the impedance mismatch problem in high-frequency transmission. At present, impedance matching tuning is a commonly used antenna tuning scheme in antenna tuning technology. Impedance matching tuning changes the RF signal transmission characteristics on the transmission path from the signal source to the transmitting antenna, or the RF signal transmission characteristics on the receiving path from the receiving antenna to the low-noise amplifier of the RF front end by adding an impedance matching network between the signal source and the load and adjusting the parameters of the impedance matching network, thereby ensuring that the source impedance and the load impedance meet or are close to the power matching condition. The impedance matching network is usually a passive network composed of adjustable devices (such as adjustable capacitors or adjustable inductors, switches) and non-adjustable devices (such as fixed capacitors or inductors). The transmission performance is improved by changing the network parameters of the impedance matching network.

[0004] In the prior art, multiple groups of network parameters of the impedance matching network (for example, scattering parameters of a two-port network) are usually stored in the terminal. When antenna tuning is required, a corresponding group of network parameters can be selected from the multiple groups of network parameters based on the current antenna impedance, and the network parameters of the impedance matching network are adjusted to the selected group of network parameters. The corresponding group of network parameters and antenna impedance can achieve power matching between source impedance and load impedance, so that the maximum transmission gain or the minimum standing wave ratio can be achieved when transmitting radio frequency signals based on the adjusted group of network parameters. However, since each group of network parameters of the impedance matching network includes 4 complex values, when the number of these multiple groups of network parameters is large (usually thousands), a large storage overhead is required, resulting in an increase in equipment cost. Summary of the invention

[0005] The present application provides an antenna tuning device and method for reducing storage overhead and tuning delay during antenna tuning.

[0006] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, an antenna tuning device is provided, the device comprising: an impedance tuning circuit coupled to an antenna, for providing impedance matching, wherein the impedance matching may be impedance matching between a radio frequency front-end module and the antenna, the impedance tuning circuit being used to ensure that the impedance of the radio frequency front-end module and the impedance of the antenna meet or are close to a power matching condition; the impedance tuning circuit having a reference state, wherein the reference state is a preset state among a plurality of impedance tuning circuit states, and the reference state is used to measure a state parameter of the antenna, wherein the state parameter may be a reflection coefficient or an impedance value; and an interface circuit, for receiving a first control signal, wherein the first control signal is used to place the impedance tuning circuit in a reference state.

[0008] In the above technical solution, the first control signal received by the interface circuit can be used to set the impedance tuning circuit to a reference state, and the reference state is used to measure the state parameters of the antenna, that is, the state parameters of the antenna are measured in the reference state, and the impedance tuning circuit can provide impedance matching based on the state parameters. The reference state is a preset state among multiple impedance tuning circuit states. In this way, in the impedance matching process, it is only necessary to perform impedance tuning based on the state parameters of the antenna measured in the reference state, and there is no need to perform impedance tuning in other states among the multiple impedance tuning circuit states. Compared with the prior art, the storage overhead and tuning delay in the antenna tuning process are greatly reduced, thereby reducing equipment costs and improving user experience.

[0009] In a possible implementation of the first aspect, the impedance tuning circuit includes an impedance tuner and a switch circuit connected in parallel, and the reference state is the state of the impedance tuning circuit when the switch circuit is closed, for example, the first control signal can be used to control the closure of the switch circuit. In the above possible implementation, when the switch circuit is closed, the impedance tuner is bypassed, and the impedance tuning circuit can be approximately equivalent to a radio frequency transmission line. The reference state can also be called a through state, so that when measuring the state parameters of the antenna, it is not affected by the impedance of the impedance tuner, thereby greatly improving the measurement accuracy of the state parameters of the antenna.

[0010] In a possible implementation of the first aspect, the absolute value of the port reflection parameter of the impedance tuning circuit in the reference state is less than a first threshold, and the absolute value of the inter-port transmission parameter is greater than a second threshold. In the above possible implementation, the influence of the impedance tuning circuit on the state parameters of the antenna can be reduced when measuring the state parameters of the antenna, thereby greatly improving the measurement accuracy of the state parameters of the antenna.

[0011] In a possible implementation of the first aspect, the device further includes: a reflection coefficient detector, which is used to measure the state parameters of the antenna when the impedance tuning circuit is in the reference state. Optionally, the reflection coefficient detector is used to measure a first reflection coefficient when the impedance tuning circuit is in the reference state. The first reflection coefficient may be a reflection coefficient at a coupling point where the reflection coefficient detector is used to couple the radio frequency signal. The first reflection coefficient may be used to determine the state parameters of the antenna. Exemplarily, the reflection coefficient detector is a directional coupler, which may be used to obtain a forward coupling signal and a reverse coupling signal of the radio frequency signal on the transmission path, so that the first reflection coefficient at the coupling point may be determined based on the forward coupling signal and the reverse coupling signal. In the above possible implementation, the parameters of the antenna state may be determined by the radio frequency signal coupled by the reflection coefficient detector.

[0012] In a possible implementation of the first aspect, the device further includes: a processor, configured to determine a second reflection coefficient based on a first reflection coefficient and a first parameter model, wherein the first parameter model is configured to indicate a corresponding relationship between the first reflection coefficient and the second reflection coefficient. The first parameter model may be obtained based on a plurality of first reflection coefficients and a plurality of second reflection coefficients obtained by prior measurement at a certain frequency and temperature. In the above possible implementation, by establishing a first parameter model and determining the second reflection coefficient based on the first reflection coefficient and the first parameter model, the state parameter of the antenna may be determined.

[0013] In a possible implementation of the first aspect, the device further includes: a processor coupled to the interface circuit, and configured to output a first control signal; optionally, the processor is a baseband processor, a radio frequency processor, or a microprocessor. Optionally, the processor can be configured to output a first control signal when a preset condition is met, that is, the processor can output a first control signal through the interface circuit when the preset condition is met to set the impedance tuning circuit to a reference state, and the preset condition can include any of the following: a specified event occurs, such as a frequency band switch or an antenna switch, and a preset time has passed since the last tuning. In the above possible implementations, by setting the impedance tuning circuit to a reference state through a first control signal when the preset condition is met, thereby measuring the state parameters of the antenna in the reference state, the storage overhead in the antenna tuning process can be greatly reduced, thereby reducing the equipment cost.

[0014] In a possible implementation of the first aspect, the processor is further used to: when it is determined that the offset modulus of the reflection coefficient of the antenna currently obtained is greater than a preset threshold, based on the reflection coefficient of the antenna currently obtained and the second parameter model, obtain the impedance control word of the second state, the second parameter model is used to indicate the impedance control word of the impedance tuning circuit state corresponding to each antenna reflection coefficient in the multiple antenna reflection coefficients, for example, the second parameter model is a mapping function between the antenna reflection coefficient and the impedance control word of the impedance tuning circuit state; output a second control signal for indicating the impedance control word of the second state through the interface circuit, so as to set the impedance tuning circuit to the second state through the second control signal, so that the antenna tuning device is in an impedance matching state. In the above possible implementation, when the impedance control word of the second state is obtained through the reflection coefficient of the antenna currently obtained and the second parameter model established in advance, there is no need to store a large number of antenna reflection coefficients and a large number of impedance tuning circuit state impedance control words, thereby saving storage space and reducing equipment costs.

[0015] In a possible implementation of the first aspect, the device also includes the antenna, which is an aperture-adjustable antenna; the aperture-adjustable antenna is used to adjust the state parameters of the antenna to provide impedance matching; that is, the processor can first adjust the aperture in the aperture-adjustable antenna to a first aperture state, and then adjust the state of the impedance tuning circuit according to the antenna reflection coefficient corresponding to the first aperture state to achieve impedance matching. In the above possible implementation, by first adjusting the aperture in the aperture-adjustable antenna, and then adjusting the state of the impedance tuning circuit according to the antenna reflection coefficient corresponding to the adjusted aperture state to achieve impedance matching, the load variation range that the impedance tuning circuit needs to adapt can be greatly reduced, thereby reducing the degree of freedom required for the impedance tuning circuit, and thus reducing the cost of the device.

[0016] In a possible implementation of the first aspect, the aperture-adjustable antenna has multiple aperture states, and in a certain fixed antenna working scenario, each aperture state in the multiple aperture states corresponds to a resonant frequency point, and the multiple aperture states are arranged in a monotonic order according to the corresponding resonant frequency points, for example, arranged in order from low to high or from high to low according to the resonant frequency points, and each aperture state in the multiple aperture states corresponds to an antenna reflection coefficient, then the processor can select the first aperture state corresponding to the minimum reflection coefficient modulus value from the multiple aperture states, and set the aperture-adjustable antenna to the first aperture state. In the above possible implementation, when the aperture state is adaptively selected based on the sorted multiple aperture states, the delay of aperture tuning can be greatly reduced.

[0017] In a possible implementation manner of the first aspect, the device also includes a radio frequency front-end module, the impedance tuning circuit is coupled between the radio frequency front-end module and the antenna, and the impedance matching is an impedance matching between the radio frequency front-end module and the antenna.

[0018] In a possible implementation manner of the first aspect, the radio frequency front-end module includes at least one of the following: a power amplifier, a filter, a low noise amplifier, and a duplexer.

[0019] In a possible implementation of the first aspect, the device also includes: a radio frequency integrated circuit, used to provide digital-to-analog / analog-to-digital conversion during the measurement of the state parameters of the antenna; optionally, the radio frequency integrated circuit includes: an analog-to-digital / digital-to-analog converter, a low-pass filter, an up / down converter, and a driver amplifier.

[0020] In a second aspect, an antenna tuning method is provided, the method comprising: setting an impedance tuning circuit to a reference state, the reference state being a preset state among multiple states of the impedance tuning circuit; measuring a state parameter of the antenna in the reference state, the state parameter being a reflection coefficient or an impedance value; performing impedance tuning based on the state parameter to achieve impedance matching, the impedance matching being an impedance matching between a radio frequency front-end module and the antenna, the impedance tuning circuit being used to ensure that the impedance of the radio frequency front-end module and the impedance of the antenna meet or are close to a power matching condition.

[0021] In a possible implementation manner of the second aspect, the impedance tuning circuit includes an impedance tuner and a switch circuit connected in parallel, and the reference state is a state of the impedance tuning circuit when the switch circuit is closed.

[0022] In a possible implementation manner of the second aspect, a port reflection parameter of the impedance tuning circuit in the reference state is less than a first threshold, and a port-to-port transmission parameter is greater than a second threshold.

[0023] In a possible implementation of the second aspect, measuring the state parameter of the antenna in the reference state includes: measuring a first reflection coefficient when the impedance tuning circuit is in the reference state, the first reflection coefficient may be a reflection coefficient at a coupling point used by a reflection coefficient detector to couple a radio frequency signal, and the first reflection coefficient may be used to determine the state parameter of the antenna. Exemplarily, the reflection coefficient detector includes a directional coupler, which may be used to obtain a forward coupling signal and a reverse coupling signal of the radio frequency signal on the transmission path, so that the first reflection coefficient at the coupling point may be determined based on the forward coupling signal and the reverse coupling signal.

[0024] In a possible implementation manner of the second aspect, the method further includes: determining the second reflection coefficient according to the first reflection coefficient and a first parameter model, wherein the first parameter model is used to indicate a corresponding relationship between the first reflection coefficient and the second reflection coefficient.

[0025] In a possible implementation of the second aspect, performing impedance tuning based on the state parameter further includes: performing impedance tuning based on the state parameter when a preset condition is met; wherein the preset condition may include any one of the following: a specified event occurs for a preset duration.

[0026] In a possible implementation of the second aspect, impedance tuning is performed based on the state parameter to achieve impedance matching, and also includes: when it is determined that the offset modulus of the reflection coefficient of the antenna currently obtained is greater than a preset threshold, based on the currently obtained reflection coefficient of the antenna and the second parameter model, an impedance control word of the second state is obtained, the second parameter model is used to indicate the impedance control word of the impedance tuning circuit state corresponding to each antenna reflection coefficient in multiple antenna reflection coefficients, for example, the second parameter model is a mapping function between the antenna reflection coefficient and the impedance control word of the impedance tuning circuit state; based on the impedance control word of the second state, the impedance tuning circuit is set to the second state, so that the antenna tuning device is in an impedance matching state.

[0027] In a possible implementation of the second aspect, impedance tuning is performed based on the state parameter to achieve impedance matching, including: performing aperture tuning on the antenna based on the state parameter; tuning the impedance tuning circuit based on the state parameter after the aperture tuning to achieve impedance matching. That is, firstly adjusting the aperture in the aperture adjustable antenna to a first aperture state, and then adjusting the state of the impedance tuning circuit according to the antenna reflection coefficient corresponding to the first aperture state to achieve impedance matching.

[0028] In a possible implementation of the second aspect, the aperture adjustable antenna has multiple aperture states, and the multiple aperture states are arranged in order from low to high according to the corresponding frequency points, and each aperture state corresponds to an antenna reflection coefficient. Then, the first aperture state corresponding to the minimum reflection coefficient modulus value can be selected from the multiple aperture states, and the aperture adjustable antenna is set to the first aperture state.

[0029] In a possible implementation manner of the second aspect, the impedance matching is impedance matching between the radio frequency front-end module and the antenna.

[0030] According to a third aspect, an antenna tuning method is provided, the method comprising: generating a first control signal, the first control signal being used to place an impedance tuning circuit in a reference state, the reference state being a preset state among a plurality of states of the impedance tuning circuit; determining a state parameter of the antenna in the reference state, the state parameter being a reflection coefficient or an impedance value; performing impedance tuning based on the state parameter to achieve impedance matching, the impedance matching being an impedance matching between a radio frequency front-end module and the antenna, the impedance tuning circuit being used to ensure that the impedance of the radio frequency front-end module and the impedance of the antenna meet or are close to a power matching condition.

[0031] In a possible implementation manner of the third aspect, the impedance tuning circuit includes an impedance tuner and a switch circuit connected in parallel, and the reference state is a state of the impedance tuning circuit when the switch circuit is closed.

[0032] In a possible implementation manner of the third aspect, a port reflection parameter of the impedance tuning circuit in the reference state is less than a first threshold, and a port-to-port transmission parameter is greater than a second threshold.

[0033] In a possible implementation of the third aspect, determining the state parameters of the antenna in the reference state includes: determining a first reflection coefficient when the impedance tuning circuit is in the reference state, the first reflection coefficient may be a reflection coefficient at a coupling point used by a reflection coefficient detector to couple a radio frequency signal, and the first reflection coefficient may be used to determine the state parameters of the antenna. Exemplarily, the reflection coefficient detector includes a directional coupler, which may be used to obtain a forward coupling signal and a reverse coupling signal of the radio frequency signal on the transmission path, so that the processor may determine the first reflection coefficient at the coupling point based on the forward coupling signal and the reverse coupling signal.

[0034] In a possible implementation manner of the third aspect, the method further includes: determining the second reflection coefficient according to the first reflection coefficient and a first parameter model, wherein the first parameter model is used to indicate a corresponding relationship between the first reflection coefficient and the second reflection coefficient.

[0035] In a possible implementation of the third aspect, performing impedance tuning based on the state parameter further includes: when a preset condition is met, performing impedance tuning based on the state parameter; wherein the preset condition may include any one of the following: a specified event occurs and a preset duration is reached.

[0036] In a possible implementation of the third aspect, impedance tuning is performed based on the state parameter to achieve impedance matching, and also includes: when it is determined that the offset modulus of the currently acquired reflection coefficient of the antenna is greater than a preset threshold, based on the currently acquired reflection coefficient of the antenna and a second parameter model, an impedance control word of a second state is acquired, the second parameter model is used to indicate an impedance control word of an impedance tuning circuit state corresponding to each antenna reflection coefficient in a plurality of antenna reflection coefficients, for example, the second parameter model is a mapping function between the antenna reflection coefficient and the impedance control word of the impedance tuning circuit state; based on the impedance control word of the second state, the impedance tuning circuit is set to the second state, so that the antenna tuning device is in an impedance matching state.

[0037] In a possible implementation of the third aspect, impedance tuning is performed based on the state parameter to achieve impedance matching, including: performing aperture tuning on the antenna based on the state parameter; tuning the impedance tuning circuit based on the state parameter after the aperture tuning to achieve impedance matching. That is, the processor may first adjust the aperture in the aperture adjustable antenna to a first aperture state, and then adjust the state of the impedance tuning circuit according to the antenna reflection coefficient corresponding to the first aperture state to achieve impedance matching.

[0038] In a possible implementation of the third aspect, the aperture adjustable antenna has multiple aperture states, and the multiple aperture states are arranged in order from low to high according to the corresponding frequency points, and each aperture state corresponds to an antenna reflection coefficient. Then, the first aperture state corresponding to the minimum reflection coefficient modulus value can be selected from the multiple aperture states, and the aperture adjustable antenna is set to the first aperture state.

[0039] In a possible implementation manner of the third aspect, the impedance matching is impedance matching between the radio frequency front-end module and the antenna.

[0040] In another aspect of the present application, a computer-readable storage medium is provided, in which a computer program is stored. When the computer-readable storage medium is run on a device, the device executes the antenna tuning method provided in the second aspect or any possible implementation of the second aspect.

[0041] In another aspect of the present application, a computer-readable storage medium is provided, in which a computer program is stored. When the computer-readable storage medium is run on a device, the device executes the antenna tuning method provided in the third aspect or any possible implementation of the third aspect.

[0042] According to another aspect of the present application, a computer program product is provided. When the computer program product is run on a computer, the computer is enabled to execute the antenna tuning method provided by the second aspect or any possible implementation of the second aspect.

[0043] According to another aspect of the present application, a computer program product is provided. When the computer program product is run on a computer, the computer is enabled to execute the antenna tuning method provided by the third aspect or any possible implementation of the third aspect.

[0044] It can be understood that any of the antenna tuning methods, readable storage media and computer program products provided above include the technical features of the corresponding devices provided above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects in the corresponding devices provided above and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A schematic diagram of the structure of a terminal provided in an embodiment of the present application;

[0046] Figure 2 A schematic diagram of the structure of a radio frequency transmission model provided in an embodiment of the present application;

[0047] Figure 3 A schematic diagram of the structure of an antenna tuning device provided in an embodiment of the present application;

[0048] Figure 4 A schematic diagram of the structure of another antenna tuning device provided in an embodiment of the present application;

[0049] Figure 5 A schematic diagram of the structure of another antenna tuning device provided in an embodiment of the present application;

[0050] Figure 6 A schematic diagram of mapping multiple groups of data pairs provided in an embodiment of the present application;

[0051] Figure 7 A schematic diagram of the structure of another antenna tuning device provided in an embodiment of the present application;

[0052] Figure 8 A schematic diagram of selecting an aperture state provided in an embodiment of the present application;

[0053] Fig. 9 A schematic diagram of the structure of another antenna tuning device provided in an embodiment of the present application;

[0054] Fig.10 A schematic diagram of a flow chart of an antenna tuning method provided in an embodiment of the present application;

[0055] Fig.11A schematic diagram of a flow chart of another antenna tuning method provided in an embodiment of the present application;

[0056] Fig.12 A flowchart of another antenna tuning method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] In this application, "at least one" means one or more, and "more" means two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items 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, b and c, where a, b, c can be single or multiple. In addition, the embodiments of the present application use words such as "first" and "second" to distinguish objects with similar names, functions or effects. Those skilled in the art can understand that words such as "first" and "second" do not limit the quantity and execution order. The term "coupled" is used to indicate electrical connection, including direct connection through a wire or a connection terminal or indirect connection through other devices. Therefore, "coupling" should be regarded as a broad electronic communication connection.

[0058] In this application, the words "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in this application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the words "exemplary" or "for example" is intended to present the related concepts in a concrete way.

[0059] The technical solution of the present application can be applied to various wireless communication devices using antenna tuning devices. The wireless communication device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted. It can also be deployed on the water surface (such as a ship, etc.). It can also be deployed in the air (such as on an airplane, a balloon, and a satellite, etc.). For example, the wireless channel device can be a terminal, including but not limited to: a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device (such as a smart watch, a smart bracelet, a pedometer, etc.), a vehicle-mounted device (such as a car, a bicycle, an electric car, an airplane, a ship, a train, a high-speed train, etc.), a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a smart home device (such as a refrigerator, a television, an air conditioner, an electric meter, etc.), an intelligent robot, a workshop equipment, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, or a wireless terminal in a smart home, a flying device (such as an intelligent robot, a hot air balloon, a drone, an airplane), etc.

[0060] Figure 1 The present invention provides a schematic diagram of the structure of a terminal, which is described by taking a mobile phone as an example. The terminal includes: a baseband processor (modem), a radio frequency integrated circuit (RFIC), a radio frequency front end module (RF FEM) and an antenna.

[0061] Among them, the baseband processor has a baseband processing function and can be used to process the baseband signal. The radio frequency integrated circuit RFIC can be used to realize modulation or demodulation between the baseband signal and the radio frequency signal. The radio frequency integrated circuit RFIC may include one or more transmitting channels and one or more receiving channels, each transmitting channel may include an analog-to-digital converter (DAC), a low pass filter (LPF) and an upconverter (upconverter), and a driver amplifier (DA), and each receiving channel may include a digital-to-analog converter (ADC), a low pass filter (LPF) and a downconverter (down converter). The radio frequency front-end module RF FEM can be used to provide functions such as power amplification or filtering. The RF front-end module may also include one or more transmit (Tx) channels and one or more receive (Rx) channels. Each transmit channel may include a power amplifier (PA), a transmit filter (Tx filter) and a duplexer. Each receive channel may include a low noise amplifier (LNA) and a duplexer. The duplexer may also be replaced by an antenna switch. The antenna can be used to receive or send signals, that is, to achieve energy conversion between RF signals and electromagnetic waves.

[0062] Further, such as Figure 1 As shown, the terminal also includes an antenna tuning device, which can be used to achieve impedance matching from the RF front-end module RF FEM to the antenna. The antenna tuning device may include one or more devices, such as Figure 1 The antenna tuning device may include a directional coupler and an impedance tuning circuit as an example. Optionally, all devices or functions in the antenna tuning device may be separately configured, or some or all of the devices or functions may be integrated into the baseband processor, radio frequency integrated circuit RFIC, radio frequency front-end module RF FEM or antenna of the terminal, and the present application does not impose any specific restrictions on this.

[0063] In the antenna tuning device, the reflection coefficient and standing wave ratio of the coupling point and other parameters can be obtained by detecting the forward coupling signal and the reverse coupling signal on the transmission path (for example, the transmission channel or the receiving channel) through the directional coupler, and the impedance matching state of the antenna can be monitored in real time based on the parameters. If the impedance mismatch occurs, the impedance matching can be achieved by tuning the impedance tuning circuit, so as to improve the transmission performance of the transmission path. Among them, when measuring the reflection coefficient at the antenna entrance from the coupling point of the directional coupler, the antenna tuning device can be equivalent to the following Figure 2 The RF transmission model shown in the figure, if the reflection coefficient measured at the coupling point is expressed as Γ in , the reflection coefficient on the load side is expressed as Γ L , then the transmission between the coupling point and the load can be equivalent to a transmission matrix S (including S 11 , S 12 , S 21 and S 22 ). Figure 2 In the two-port network, the left side is the signal source AC and the equivalent internal impedance is Z S , the right side of the two-port network is the load and the impedance is Z L , Γ L With Z L The following formula (1) is satisfied between them, where Z 0 Represents the characteristic impedance of the transmission line. The reflection coefficient Γ on both sides of the two-port network in and Γ L , and the transmission matrix S (including S 11 , S 12 , S 21 and S 22 ) satisfy the following formula (2). Where S 11 Represents the reflection parameter of the first port (or input port), S 22 represents the reflection parameter of the second port (or output port), which may be a voltage reflection coefficient, S 12 represents the port-to-port transmission parameter from the first port to the second port, S 21 The transmission gain between the second port and the first port represents a transmission parameter between the second port and the first port. The transmission gain between the ports may be a voltage gain.

[0064]

[0065]

[0066] Figure 3 This is a structural schematic diagram of an antenna tuning device provided in an embodiment of the present application. The antenna tuning device includes: an impedance tuning circuit 31 and an interface circuit 32 coupled to the impedance tuning circuit 31 , and the impedance tuning circuit 31 is coupled to an antenna 30 .

[0067] The impedance tuning circuit 31 is used to provide impedance matching, for example, when the impedance of the antenna 30 changes with the change of the working frequency or the use scenario, it is always used to maintain impedance matching. The impedance matching can specifically refer to that the signal source impedance and the load impedance meet or are close to the power matching condition, that is, the signal source impedance and the load impedance meet the conjugate equality. Here, the signal source and the impedance are related to the transmission direction of the signal. In a possible embodiment, when the antenna tuning device is applied to a wireless communication device including a radio frequency front-end module, the impedance matching can be the impedance matching between the radio frequency front-end module and the antenna 30, and the impedance tuning circuit 31 is coupled between the radio frequency front-end module and the antenna 30 to ensure that the impedance of the radio frequency front-end module and the impedance of the antenna 30 meet or are close to the power matching condition. Among them, when the antenna 30 is used to receive radio frequency signals, the antenna 30 is a signal source, and the radio frequency front-end module is a load; when the antenna 30 is used to send radio frequency signals, the radio frequency front-end module is a signal source, and the antenna 30 is a load.

[0068] The impedance tuning circuit 31 has a reference state, which is a preset state in a plurality of impedance tuning circuit 31 states, and the reference state is used to measure the state parameters of the antenna. The impedance tuning circuit 31 may include: one or more tunable devices (e.g., adjustable capacitors, adjustable inductors, or switches, etc.), and / or one or more non-tunable devices (e.g., fixed capacitors or inductors, etc.). The plurality of impedance tuning circuit 31 states may be composed of a combination of the state of the one or more tunable devices and the state of the one or more non-tunable devices. For example, the impedance tuning circuit includes adjustable capacitors C1 and C2. Assuming that the adjustable capacitors C1 and C2 both include adjustments of three different capacitance values, the state of the adjustable capacitor C1 and the state of the adjustable capacitor C2 can be combined to obtain 9 combination states. If the equivalent capacitances in the 9 combination states are not equal, the plurality of impedance tuning circuit 31 states may be the 9 combination states, and the reference state may be pre-set to one of the 9 combination states.

[0069] The interface circuit 32 is used to receive the first control signal S C1 , the first control signal S C1 It is used to set the impedance tuning circuit 31 to a reference state. C1 The impedance control word can be used to indicate the reference state. For example, the impedance tuning circuit 31 includes one or more adjustable devices and one or more non-adjustable devices. The impedance control word may include the state of each of the one or more adjustable devices and the state of each of the one or more non-adjustable devices in the reference state.

[0070] In the embodiment of the present application, the first control signal S received by the interface circuit 32 C1 It can be used to set the impedance tuning circuit 31 to a reference state, and the reference state is used to measure the state parameters of the antenna 30, that is, the state parameters of the antenna 30 are measured in the reference state, and the impedance tuning circuit 31 can provide impedance matching based on the state parameters. The reference state is a preset state among multiple impedance tuning circuit 31 states. In this way, in the impedance matching process of the antenna 30, it is only necessary to perform impedance tuning based on the state parameters of the antenna measured in the reference state, and there is no need to perform impedance tuning in other states among the multiple impedance tuning circuit states. Compared with the prior art, the storage overhead and tuning delay in the antenna tuning process are greatly reduced, thereby reducing equipment costs and improving user experience.

[0071] In a possible embodiment, the absolute value of the port reflection parameter of the impedance tuning circuit 31 in the reference state is less than the first threshold, and the absolute value of the port transmission parameter is greater than the second threshold. If the ports at both ends of the impedance tuning circuit 31 are represented as the first port and the second port, the port reflection parameter may include the reflection parameter S of the first port. 11 and the reflection parameter S of the second port 22 The inter-port transmission parameter may include an inter-port transmission parameter S from the first port to the second port. 12 , and the port transmission parameter S from the second port to the first port 21 , then the impedance tuning circuit 31 satisfies the following in this reference state: |S 11 |≤Δ 1 ,|S 22 |≤Δ 1 ,|S 12 |≥Δ 2 ,|S 21 |≥Δ 2 . Among them, Δ 1 , Δ 2 denote the first threshold and the second threshold respectively, for example, Δ 1 =0.2,Δ 2 =0.8.

[0072] For example, Figure 4As shown, the impedance tuning circuit 31 includes an impedance tuner 311 and a switch circuit 312 connected in parallel. The reference state is the state of the impedance tuning circuit 31 when the switch circuit 312 is closed. When the switch circuit 312 is closed, the impedance tuner 311 is bypassed. At this time, the impedance tuning circuit 31 can be approximately equivalent to a radio frequency transmission line. The reference state can also be called a straight-through state. In this way, when measuring the state parameters of the antenna 30, the impedance of the impedance tuner 311 is not affected, thereby greatly improving the measurement accuracy of the state parameters of the antenna 30. Among them, the port reflection parameter S of the radio frequency transmission line 11 and S 22 Satisfaction|S 12 |=|S 21 |=1, the transmission parameters between ports satisfy |S 11 |=|S 22 |=0.

[0073] Alternatively, the impedance tuning circuit 31 may include only the impedance tuner 311 but not the switch circuit 312. In this case, the reference state may be a specific state among multiple impedance tuner 311 states, and the specific state may have a smaller port reflection parameter and a larger inter-port transmission parameter.

[0074] Further, such as Figure 5 As shown, the device also includes: a reflection coefficient detector 33, which is used to measure a first reflection coefficient when the impedance tuning circuit 31 is in the reference state. The first reflection coefficient can be a reflection coefficient at a coupling point where the reflection coefficient detector 33 is used to couple the radio frequency signal. The first reflection coefficient can be used to determine the state parameter of the antenna 30. Among them, the reflection coefficient detector 33 can be a directional coupler, which can be used to obtain a forward coupling signal and a reverse coupling signal of the radio frequency signal on the transmission path. The first reflection coefficient at the coupling point can be determined based on the forward coupling signal and the reverse coupling signal. In addition, the state parameter of the antenna 30 can be a reflection coefficient or an impedance value. The reflection coefficient and the impedance value of the antenna 30 can satisfy the following formula (3), where Γ Ant represents the reflection coefficient of the antenna 30, Z Ant represents the impedance value of the antenna 30, Z 0 Represents the characteristic impedance of the transmission line, usually a constant of 50 ohms.

[0075]

[0076] It should be noted that the first reflection coefficient at the coupling point is determined based on the forward coupling signal and the reverse coupling signal, the reflection coefficient of the antenna 30 is determined according to the impedance value of the antenna 30, or the relevant calculation of determining the impedance value of the antenna 30 based on the reflection coefficient of the antenna 30 can be performed by the processor 34 below.

[0077] Further, such as Figure 5 As shown, the device also includes: a processor 34 coupled to the interface circuit 32, configured to output a first control signal S C1 The processor 34 may be a baseband processor, a microprocessor or other processors, etc., and the present application embodiment does not impose any specific restrictions on this. Specifically, when it is necessary to measure the state parameters of the antenna 30 through the antenna tuning device, the processor 34 may output the first control signal S through the interface circuit 32. C1 , so as to set the impedance tuning circuit 31 to a reference state, so that the reflection coefficient detector 33 can measure the state parameter of the antenna 30, that is, measure the reflection coefficient or impedance value of the antenna when the impedance tuning circuit 31 is in the reference state. The reflection coefficient of the antenna 30 is referred to as the second reflection coefficient hereinafter, and the first reflection coefficient is used to determine the second reflection coefficient as an example for explanation.

[0078] Exemplarily, the processor 34 may be configured to output a first control signal S when a preset condition is met. C1 , that is, the processor 34 can output the first control signal S through the interface circuit 32 when the preset condition is met. C1 , so as to set the impedance tuning circuit 31 to the reference state, the preset condition may include any of the following: a specified event occurs and a preset duration is reached. The specified event and the preset duration may be set in advance, for example, the specified event may include one or more of a frequency switching event, a communication interruption event or an antenna switching event, and the preset duration may be 50ms or 500ms, etc.

[0079] Optionally, the processor 34 is further used to: determine the second reflection coefficient of the antenna 30 according to the first reflection coefficient. In a possible implementation, the processor 34 determines the second reflection coefficient according to the first reflection coefficient and the first parameter model, and the first parameter model is used to indicate the corresponding relationship between the first reflection coefficient and the second reflection coefficient. The first parameter model can be obtained based on a plurality of first reflection coefficients and a plurality of second reflection coefficients obtained by prior measurement at a certain frequency and temperature. By establishing the first parameter model and determining the second reflection coefficient according to the first reflection coefficient and the first parameter model, the state parameters of the antenna can be determined.

[0080] Exemplarily, the portion between the coupling point of the reflection coefficient detector 33 and the entrance of the antenna 30 is a two-port network with fixed parameters when the impedance tuning circuit 31 is in the reference state, that is, S 11 , S 12 , S 21 and S 22Based on the transmission characteristics of the two-port network, a first parameter model is established at a reference operating frequency (eg, the center carrier frequency of a narrowband system) and room temperature of 25 degrees Celsius as shown in the following formula (4).

[0081]

[0082] In the formula, Γ Ant represents the second reflection coefficient at the entrance of antenna 30, Γ Cpl represents the first reflection coefficient measured at the coupling point, a, b, c represent the complex coefficients in the first parameter model, and the relationship between them and the transmission parameters of the two-port network composed of two ports is a = -S 11 , b=S 12 S 21 -S 22 S 11 , c=S 22 .

[0083] In an exemplary embodiment, the processor 34 respectively sets the impedance tuning circuit to the reference state through the interface circuit 32 to obtain the first reflection coefficients corresponding to at least three different second reflection coefficients, that is, to obtain at least three reflection coefficient pairs, each reflection coefficient pair including a first reflection coefficient Γ Cpl and a second reflection coefficient Γ Ant Then, the three complex coefficients a, b, c can be determined based on the above formula (4) based on at least three reflection coefficient pairs. Alternatively, the three complex coefficients a, b, c can be determined based on any three reflection coefficient pairs among the at least three reflection coefficient pairs and the following formula (5). Where, (Γ in (i) , Γ MRx (i) ), i=1, 2, N represents at least three reflection coefficient pairs.

[0084]

[0085] In another example, when the two-port network formed by the coupling point of the reflection coefficient detector 33 and the input port of the antenna 30 can be connected to other instruments, the parameters of the two-port network in the reference state (i.e., S 11 , S 12 , S 21 and S 22 For example, these instruments can be vector network analyzers, which can be used to measure the parameters of the two-port network of the impedance tuner in the reference state at a reference operating frequency (for example, the center carrier frequency of a narrowband system) and at room temperature of 25 degrees Celsius, that is, to measure S 11 , S 12 , S 21 and S22 .

[0086] Further, in one embodiment, the processor 34 is further configured to: when it is determined that the offset modulus of the reflection coefficient of the antenna 30 is greater than a preset threshold, output a second control signal S corresponding to the reflection coefficient of the antenna 30 C2 , the offset modulus is the absolute value of the difference between the currently acquired reflection coefficient of the antenna 30 and the initial reflection coefficient when the impedance tuning circuit 31 is in the first state, the first state is the state of the impedance tuning circuit 31 before the reference state, and the initial reflection coefficient in the first state is measured when the device is in the first state of impedance matching; the interface circuit 32 is also used to: receive the second control signal S C2 , the second control signal S C2 The impedance tuning circuit 31 is set to the second state among the multiple impedance tuning circuit 31 states. For example, the processor 34 determines the impedance control word of the second state corresponding to the reflection coefficient of the antenna 30 according to the second parameter model, and the second parameter model can be used to indicate the impedance control word of the impedance tuning circuit 31 state corresponding to each antenna reflection coefficient among the multiple antenna reflection coefficients, so that the processor 34 can output the second control signal S for indicating the impedance control word of the second state through the interface circuit 32. C2 , through the second control signal S C2 The impedance tuning circuit 31 is set to the second state.

[0087] For example, it is assumed that the impedance tuning circuit 31 includes two adjustable capacitors C 1 and C 2 , the mapping relationship (also called the second parameter model) between the antenna 30 and the corresponding optimal impedance control word under different load values ​​can be established in an offline manner (for example, by measuring and screening with a measuring instrument in a laboratory environment, etc.), for example, the influence of the scattering matrix S of the matching network under different impedance control codewords on the system transmission gain is established, so as to obtain Figure 6 The multiple data sets shown are {Γ Ant , (C 1 , C 2 )}, and then the second parameter model is established by fitting the function model as shown in the following formula: Figure 6 The circles in the figure represent different resistance circles in the Smith chart, and the black dots in the circles represent different antenna reflection coefficients or impedance values.

[0088] (C 1 , C 2 )=f(Γ Ant )

[0089] Among them, C 1 and C 2is the control code word (i.e., impedance control word) in the impedance tuning circuit 31. For example, the control code word may be the adjustable capacitor C 1 and C 2 The bias voltage value or register value of Γ Ant is the detected load value of the antenna 30, which may be a complex number; f(·) is a mapping function, including but not limited to: a polynomial model, or a multi-layer neural network model, etc.

[0090] For example, for a polynomial model, the second parameter model can be f 1 (x, y) = a 0 +a 1 x+a 2 y+a 3 x 2 +a 4 xy...,a 0 to a 4 They are expressed as function model coefficients, x and y can be adjustable capacitors C 1 and C 2 For a multi-layer neural network model, the second parameter model can be f 1 (x) = δ 2 (w 2 δ 1 (w 1 x+b 1 )+b 2 ), δ 1 , δ 2 , ... is the activation function of the multi-layer neural network, w 1 , b 1 , w 2 , b 2 , ... are weight coefficient matrices or vectors in each layer of the neural network, and x can be an adjustable capacitor C 1 and C 2 Representing the data set with a function model and the corresponding model coefficients can save the storage space required for directly storing the mapping table.

[0091] Specifically, the impedance tuning circuit 31 is in a first state before being set to a reference state. In the first state, the initial reflection coefficient of the antenna can be measured, and the antenna tuning device is in an impedance matching state at the initial reflection coefficient. When the processor 34 determines that the offset modulus value of the reflection coefficient of the antenna 30 currently obtained is greater than a preset threshold, the processor 34 can obtain an impedance control word of the second state based on the reflection coefficient of the antenna 30 currently obtained and the second parameter model. Afterwards, the processor 34 can output a second control signal S indicating the impedance control word of the second state through the interface circuit 32. C2, through the second control signal S C2 The impedance tuning circuit 31 is set to the second state, so that the antenna tuning device is in an impedance matching state.

[0092] Optionally, the processor 34 may also record the first state of the impedance tuning circuit 31, for example, record the impedance control word corresponding to the first state. Thus, when the offset modulus value of the reflection coefficient of the antenna 30 is less than or equal to the preset threshold, the processor 34 may also be used to output a third control signal S C3 The interface circuit 32 is also used to receive the third control signal S C3 , the third control signal S C3 It is used to set the impedance tuning circuit 31 to the first state among the multiple impedance tuning circuit 31 states, that is, to restore the impedance tuning circuit 31 to the state before the reference state. That is, when the offset modulus value of the reflection coefficient of the antenna 30 is less than or equal to the preset threshold, the antenna tuning device is in an impedance matching state, so there is no need to perform impedance tuning, and it is only necessary to maintain the previous state of the impedance tuning circuit 31, so that the impedance tuning circuit 31 can be restored to the state before the reference state.

[0093] It should be noted that the preset threshold and the second parameter model can be set in advance, and can be specifically determined by those skilled in the art based on experimental measurements or experience, etc., and the embodiments of the present application do not impose specific limitations on this.

[0094] In the above-mentioned antenna tuning process, when obtaining the impedance control word corresponding to the second state through the currently obtained reflection coefficient of the antenna 30 and the second parameter model established in advance, there is no need to store a large number of antenna reflection coefficients and a large number of impedance control words, thereby saving storage space and reducing equipment costs.

[0095] Further, in another embodiment, if Figure 7 As shown, the device also includes the antenna 30, which is an aperture adjustable antenna, and the antenna 30 is coupled to the interface circuit 32. Accordingly, the processor 34 is also used to output the aperture adjustment signal S when the offset modulus value of the reflection coefficient of the antenna 30 is greater than the preset threshold. t The interface circuit 32 is also used to receive the aperture adjustment signal S t , the aperture adjustment signal S t It is used to adjust the aperture of the adjustable aperture antenna. For example, the aperture adjustment signal S tThe aperture in the adjustable aperture antenna is set to the first aperture state among multiple aperture states, each aperture state in the multiple aperture states corresponds to an antenna reflection coefficient, and the first aperture state is the aperture state corresponding to the modulus value of the smallest antenna reflection coefficient. That is, when the modulus value of the offset of the reflection coefficient of the antenna 30 is greater than the preset threshold, the processor 34 can first adjust the aperture in the adjustable aperture antenna to the first aperture state, and then adjust the state of the impedance tuning circuit 31 according to the antenna reflection coefficient corresponding to the first aperture state to achieve impedance matching.

[0096] Among them, since different aperture states in the aperture adjustable antenna correspond to different antenna electrical lengths, and in different use environments, the relative length relationship between the antenna electrical lengths in different aperture states remains constant, the processor 34 can make full use of this feature in the process of making an aperture state adaptive selection to avoid traversing different aperture states and causing a large aperture tuning convergence delay. Accordingly, before the aperture is adjusted, the frequency point corresponding to the reflection coefficient modulus value of the antenna 30 in different aperture states can be measured in an offline manner in a free space environment, and the frequency point corresponds to the antenna electrical length in the aperture state. The multiple aperture states are sorted and stored in the order of the corresponding frequency points in different aperture states from low to high (or from high to low), so as to be used by the processor 34 when making an aperture state adaptive selection.

[0097] Specifically, the multiple aperture states are arranged in order from low to high according to the corresponding frequency points, and each aperture state corresponds to an antenna reflection coefficient, then the processor 34 can select a first aperture state corresponding to the minimum reflection coefficient modulus value from the multiple aperture states, and output an aperture adjustment signal S for setting the aperture in the aperture adjustable antenna to the first aperture state. t Among them, the aperture adjustment signal S t It can be used to indicate the aperture control word corresponding to the first aperture state. For example, the aperture control word can be the electrical length of the antenna 30.

[0098] Optionally, the processor 34 may select the first aperture state from the plurality of aperture states according to a preset search step length, and the search step length may be fixed or variable, which is not specifically limited in the embodiment of the present application. Figure 8 As shown, it is assumed that the antenna 30 has M aperture states and the corresponding frequency points are SW 1 To SW M-1 The M multiple aperture states can be represented as SW 1 Status to SW M-1 State, the antenna reflection coefficient modulus corresponding to different aperture states |Γ Ant | is distributed between 0 and 1. If the current aperture state of the antenna 30 is SW1 state and the search step size is 1, the processor 34 can switch the aperture state to SW 2 State, at this time if SW 2 The antenna reflection coefficient modulus ratio SW 1 If the reflection coefficient modulus value is small, you can continue to press the right button to switch the aperture state to SW 3 Status (on the contrary, if the switch SW 2 The antenna reflection coefficient modulus ratio SW 1 The antenna reflection coefficient modulus is large in the state, so the aperture state is adjusted in the opposite direction to SW 0 state); similarly, due to SW 3 The antenna reflection coefficient modulus ratio SW 2 The antenna reflection coefficient modulus is small in this state, so continue to adjust the aperture state to SW 4 State, if SW 4 The antenna reflection coefficient modulus ratio SW 3 The reflection coefficient modulus value in the state is large, then it is determined that SW 3 The state is the best aperture state under the current environment, and the reflection coefficient value under the current aperture state is saved, which can be used for subsequent impedance matching tuning.

[0099] It should be noted that the process of adjusting the state of the impedance tuning circuit 31 based on the antenna reflection coefficient corresponding to the first aperture state is similar to the process of adjusting the state of the impedance tuning circuit 31 based on the reflection coefficient of the antenna 30 currently measured in the above text, with the only difference being that the reflection coefficient of the antenna 30 currently measured is replaced by the antenna reflection coefficient corresponding to the first aperture state. The specific adjustment process can be found in the description above, and the embodiments of the present application will not be repeated here.

[0100] In the above antenna tuning process, by first adjusting the aperture in the adjustable aperture antenna, and then adjusting the state of the impedance tuning circuit 31 according to the antenna reflection coefficient corresponding to the adjusted aperture state to achieve impedance matching, the load variation range that the impedance tuning circuit 31 needs to adapt to can be greatly reduced, thereby reducing the degree of freedom required for the impedance tuning circuit 31. In addition, when the aperture state is adaptively selected based on the sorted multiple aperture states, the delay of the aperture tuning can be greatly reduced.

[0101] Further, such as Fig. 9 As shown, the device may further include: a radio frequency front end module 35; and / or a radio frequency integrated circuit 36. The impedance tuning circuit 31 may be coupled between the radio frequency front end module 35 and the antenna 30 to provide impedance matching between the radio frequency front end module 35 and the antenna 30.

[0102] The RFIC 36 may be used to provide digital-to-analog / analog-to-digital conversion during the measurement of the state parameters of the antenna 30. For example, the RFIC 36 may include one or more transmitting channels and one or more receiving channels, each transmitting channel may include a DAC, an LPF, an up-converter, and a DA, and each receiving channel may include an ADC, an LPF, and a down-converter.

[0103] In addition, the RF front-end module 35 can be used to provide functions such as power amplification or filtering during the measurement of the state parameters of the antenna 30. For example, the RF front-end module 35 can also include one or more transmission channels and one or more receiving channels, each of which can include a PA, a transmission filter and a duplexer, and each of which can include an LNA and a duplexer, and the duplexer can also be replaced by an antenna switch.

[0104] exist Fig. 9 In the antenna tuning device shown, the processor 34 may be a baseband processor, or may be a processor integrated in the RF front-end module 35 or the RF integrated circuit 36, etc., and the embodiment of the present application does not impose any specific limitation on this. Fig. 9 In the description, only the processor 34 is taken as a baseband processor as an example. By integrating the processor 34 in different modules or circuits, the integration and design flexibility of the antenna tuning device can be improved.

[0105] In practical applications, the antenna tuning device may be a chip or a chipset, or the antenna tuning device may be a wireless communication device, for example, the antenna tuning device may be a terminal such as a mobile phone, a vehicle-mounted device, or a wearable device. When the terminal performs antenna tuning based on the solution provided above, the storage overhead and tuning delay in the antenna tuning process may be greatly reduced, thereby reducing the device cost and further improving the user experience.

[0106] Fig.10 A flow chart of an antenna tuning method provided in an embodiment of the present application, which can be applied to the antenna tuning device provided above, includes the following steps.

[0107] S41: setting the impedance tuning circuit to a reference state, where the reference state is a preset state among a plurality of impedance tuning circuit states.

[0108] The impedance tuning circuit may include: one or more tunable devices (e.g., tunable capacitors or tunable inductors, etc.), and / or one or more non-tunable devices (e.g., switches, etc.). Multiple impedance tuning circuit states may be composed of a combination of the states of the one or more tunable devices and the states of the one or more non-tunable devices. For example, the impedance tuning circuit includes adjustable capacitors C1 and C2. Assuming that the adjustable capacitors C1 and C2 both include adjustments of three different capacitance values, the states of the adjustable capacitors C1 and C2 may be combined to obtain nine combination states. If the equivalent capacitances in the nine combination states are not equal, the multiple impedance tuning circuit states may be the nine combination states, and the reference state may be pre-set to one of the nine combination states.

[0109] Specifically, when it is necessary to measure the state parameters of the antenna through the antenna tuning device, the processor can output a first control signal through the interface circuit to set the impedance tuning circuit to a reference state through the first control signal. In one possible implementation, the processor can output a first control signal when a preset condition is met, and the preset condition may include any of the following: a specified event occurs and a preset duration is reached. The specified event and the preset duration can be set in advance. For example, the specified event may include one or more of a frequency switching event, a communication interruption event, or an antenna switching event. The preset duration may be 50ms or 500ms, etc.

[0110] In a possible embodiment, the absolute value of the port reflection parameter of the impedance tuning circuit in the reference state is less than the first threshold, and the absolute value of the port transmission parameter is greater than the second threshold. If the ports at both ends of the impedance tuning circuit are represented as the first port and the second port, the port reflection parameter may include the reflection parameter S of the first port. 11 and the reflection parameter S of the second port 22 The inter-port transmission parameter may include an inter-port transmission parameter S from the first port to the second port. 12 , and the port transmission parameter S from the second port to the first port 21 , then the impedance tuning circuit 31 satisfies the following in this reference state: |S 11 |≤Δ 1 ,|S 22 |≤Δ 1 ,|S 12 |≥Δ 2 ,|S 21 |≥Δ 2 . Among them, Δ 1 , Δ 2 denote the first threshold and the second threshold respectively, for example, Δ 1 =0.2,Δ 2 =0.8.

[0111] Optionally, the impedance tuning circuit includes an impedance tuner and a switch circuit connected in parallel, and the reference state is the state of the impedance tuning circuit when the switch circuit is closed, so that the first control signal S output by the processor C1 It can be used to close the switch circuit. When the switch circuit is closed, the impedance tuner is bypassed. At this time, the impedance tuning circuit can be approximately equivalent to a radio frequency transmission line. The reference state can also be called a straight-through state. In this way, when measuring the state parameters of the antenna, it is not affected by the impedance of the impedance tuner, thereby greatly improving the measurement accuracy of the state parameters of the antenna. Alternatively, the impedance tuning circuit may only include an impedance tuner without a switch circuit. In this case, the reference state may be a specific state among multiple impedance tuner states, and the specific state may have a smaller port reflection parameter and a larger port-to-port transmission parameter.

[0112] S42: Measure the state parameters of the antenna under the reference state.

[0113] When the impedance tuning circuit is in the reference state, a first reflection coefficient can be measured in the reference state by a reflection coefficient detector. The first reflection coefficient can be a reflection coefficient at a coupling point used by the reflection coefficient detector to couple the radio frequency signal. The first reflection coefficient can be used to determine the state parameter of the antenna. The reflection coefficient detector can be a directional coupler, which can be used to obtain a forward coupling signal and a reverse coupling signal of the radio frequency signal on the transmission path. The first reflection coefficient at the coupling point can be determined based on the forward coupling signal and the reverse coupling signal. In addition, the state parameter of the antenna can be a reflection coefficient or an impedance value, and the reflection coefficient and the impedance value of the antenna can satisfy the above formula (3).

[0114] In a possible implementation, the processor may determine the first reflection coefficient at the coupling point based on the forward coupling signal and the reverse coupling signal, and determine the second reflection coefficient of the antenna based on the first reflection coefficient. For example, the processor determines the second reflection coefficient based on the first reflection coefficient and the first parameter model, and the first parameter model is used to indicate the corresponding relationship between the first reflection coefficient and the second reflection coefficient. The first parameter model can be obtained based on a plurality of first reflection coefficients and a plurality of second reflection coefficients obtained by prior measurement at a certain frequency and temperature. By establishing the first parameter model and determining the second reflection coefficient based on the first reflection coefficient and the first parameter model, the state parameters of the antenna can be determined.

[0115] It should be noted that, for the relevant description of the first parameter model, reference can be made to the relevant description in the corresponding device embodiment, and the embodiments of the present application will not be repeated here.

[0116] S43: Perform impedance tuning based on the state parameters of the antenna to achieve impedance matching.

[0117] Wherein, when the impedance of the antenna changes with the change of the working frequency or the use scenario, the impedance matching is always maintained. The impedance matching can specifically refer to that the signal source impedance and the load impedance meet or are close to the power matching condition, that is, the signal source impedance and the load impedance meet the conjugate equality. The signal source and impedance here are related to the transmission direction of the signal. In a possible embodiment, the impedance matching can be the impedance matching between the RF front-end module and the antenna. The impedance tuning circuit is coupled between the RF front-end module and the antenna to ensure that the impedance of the RF front-end module and the impedance of the antenna meet or are close to the power matching condition. Wherein, when the antenna is used to receive RF signals, the antenna is the signal source, and the RF front-end module is the load; when the antenna is used to send RF signals, the RF front-end module is the signal source, and the antenna is the load.

[0118] In one embodiment, the above step S43 may specifically be: when it is determined that the offset modulus of the reflection coefficient of the antenna is greater than a preset threshold, impedance tuning is performed on the impedance tuning circuit based on the reflection coefficient of the antenna to achieve impedance matching. Exemplarily, the processor may output a second control signal corresponding to the reflection coefficient of the antenna, the offset modulus being the absolute value of the difference between the currently acquired reflection coefficient of the antenna and the initial reflection coefficient when the impedance tuning circuit is in a first state, the first state being the state of the impedance tuning circuit before the reference state. The second control signal may be used to set the impedance tuning circuit to a second state among a plurality of impedance tuning circuit states.

[0119] For example, the processor can determine the second state corresponding to the reflection coefficient of the antenna according to the second parameter model, and the second parameter model can be used to indicate the impedance control word of the impedance tuning circuit state corresponding to each antenna reflection coefficient in the multiple antenna reflection coefficients, for example, the second parameter model is a mapping function between the antenna reflection coefficient and the impedance control word of the impedance tuning circuit state. In this way, the processor can output a second control signal for indicating the impedance control word of the second state, so as to set the impedance tuning circuit to the second state through the second control signal.

[0120] It should be noted that, for the relevant description of the second parameter model, reference can be made to the relevant description in the corresponding device embodiment, and the embodiments of the present application will not be repeated here.

[0121] Specifically, the impedance tuning circuit is in a first state before being set to a reference state, and the initial reflection coefficient of the antenna in the first state can be measured, and the antenna tuning device is in an impedance matching state at the initial reflection coefficient. When the processor determines that the offset modulus value of the reflection coefficient of the antenna currently obtained is greater than a preset threshold, the processor can obtain an impedance control word of the second state based on the reflection coefficient of the antenna currently obtained and the second parameter model. The processor outputs a second control signal for indicating the impedance control word of the second state through the interface circuit, so as to set the impedance tuning circuit to the second state through the second control signal, thereby putting the antenna tuning device in an impedance matching state.

[0122] Optionally, the processor may also record the first state of the impedance tuning circuit, for example, record the impedance control system corresponding to the first state. In this way, when the offset modulus of the reflection coefficient of the antenna is less than or equal to the preset threshold, the processor may also output a third control signal, and the interface circuit may receive the third control signal, and the third control signal is used to set the impedance tuning circuit to the first state among multiple impedance tuning circuit states, that is, to restore the impedance tuning circuit to the state before the reference state. That is, when the offset modulus of the reflection coefficient of the antenna is less than or equal to the preset threshold, the antenna tuning device is in an impedance matching state, so there is no need to perform impedance tuning, and it is only necessary to maintain the previous state of the impedance tuning circuit, so that the impedance tuning circuit can be restored to the state before the reference state.

[0123] In another embodiment, the antenna is an aperture adjustable antenna, and the above step S43 may include: when the offset modulus of the reflection coefficient of the antenna is greater than the preset threshold, tuning the aperture of the antenna based on the state parameters of the antenna; tuning the impedance tuning circuit based on the state parameters after the aperture tuning to achieve impedance matching. Specifically, when the offset modulus of the reflection coefficient of the antenna is greater than the preset threshold, the processor outputs an aperture adjustment signal S t , the aperture adjustment signal S t It is used to adjust the aperture of the adjustable aperture antenna. For example, the aperture adjustment signal S t The method is used to set the aperture in the adjustable aperture antenna to the first aperture state among multiple aperture states, each aperture state in the multiple aperture states corresponds to an antenna reflection coefficient, and the first aperture state is the aperture state corresponding to the modulus value of the smallest antenna reflection coefficient. That is, when the modulus value of the offset of the reflection coefficient of the antenna is greater than the preset threshold, the processor can first adjust the aperture in the adjustable aperture antenna to the first aperture state, and then adjust the state of the impedance tuning circuit according to the antenna reflection coefficient corresponding to the first aperture state to achieve impedance matching.

[0124] Among them, since different aperture states in the aperture adjustable antenna correspond to different antenna electrical lengths, and in different use environments, the relative length relationship between the antenna electrical lengths in different aperture states remains constant, the processor 34 can make full use of this feature in the process of making an aperture state adaptive selection to avoid traversing different aperture states and causing a large aperture tuning convergence delay. Accordingly, before the aperture is adjusted, the frequency point corresponding to the reflection coefficient modulus value of the antenna in different aperture states can be measured in an offline manner in a free space environment, and the frequency point corresponds to the antenna electrical length in the aperture state. The multiple aperture states are sorted and stored in the order of the corresponding frequency points in different aperture states from low to high (or from high to low), so as to be used by the processor when making an aperture state adaptive selection.

[0125] Specifically, the multiple aperture states are arranged in order from low to high according to the corresponding frequency points, and each aperture state corresponds to an antenna reflection coefficient, then the processor can select the first aperture state corresponding to the minimum reflection coefficient modulus from the multiple aperture states, and output an aperture adjustment signal for setting the aperture in the aperture adjustable antenna to the first aperture state. Among them, the aperture adjustment signal can be used to indicate the aperture control word corresponding to the first aperture state, for example, the aperture control word can be the electrical length of the antenna. Optionally, the processor can select the first aperture state from the multiple aperture states according to a preset search step size, and the search step size can be fixed or variable, and the embodiment of the present application does not impose specific restrictions on this.

[0126] It should be noted that the process of adjusting the state of the impedance tuning circuit based on the antenna reflection coefficient corresponding to the first aperture state is similar to the process of adjusting the state of the impedance tuning circuit based on the reflection coefficient of the antenna currently measured in the above text. The only difference is that the reflection coefficient of the antenna currently measured is replaced by the antenna reflection coefficient corresponding to the first aperture state. The specific adjustment process can be found in the description above, and the embodiments of the present application will not be repeated here.

[0127] In the above antenna tuning process, by first adjusting the aperture in the aperture-adjustable antenna, and then adjusting the state of the impedance tuning circuit according to the antenna reflection coefficient corresponding to the adjusted aperture state to achieve impedance matching, the load variation range that the impedance tuning circuit needs to adapt to can be greatly reduced, thereby reducing the degree of freedom required for the impedance tuning circuit. In addition, when the aperture state is adaptively selected based on the sorted multiple aperture states, the delay of aperture tuning can be greatly reduced.

[0128] For ease of understanding, the antenna tuning method provided in the embodiment of the present application is described below by taking the antenna as an antenna with a non-adjustable aperture and an antenna with an adjustable aperture as examples. Fig.11The antenna is taken as an example of an antenna with a non-adjustable aperture. Fig.12 The antenna is an aperture-adjustable antenna as an example for description.

[0129] like Fig.11 As shown, the method includes: S50. Determine whether a preset condition is met, for example, determine whether a specified event occurs or a preset duration is reached; S51. Record the current state of the impedance tuning circuit (i.e., the first state), and set the impedance tuning circuit to a reference state; S52. Measure the first reflection coefficient at the coupling point; S53. Determine the reflection coefficient of the antenna (i.e., the second reflection coefficient) based on the first reflection coefficient; S54. Determine whether the offset modulus of the reflection coefficient of the antenna is greater than a preset threshold, if so (i.e., greater than), execute S55a, if not (i.e., less than or equal to), execute S55b; S55a. Start the impedance tuning process, for example, set the impedance tuning circuit to the second state according to the reflection coefficient of the antenna; S55b. There is no need to start the impedance tuning process, for example, restore the impedance tuning circuit to the first state.

[0130] like Fig.12 As shown, the method includes: S60. Determine whether the preset conditions are met; S61. Record the current state of the impedance tuning circuit (i.e., the first state), and set the impedance tuning circuit to the reference state; S62. Measure the first reflection coefficient at the coupling point; S63. Determine the reflection coefficient of the antenna (i.e., the second reflection coefficient) according to the first reflection coefficient; S64. Determine whether the offset modulus of the reflection coefficient of the antenna is greater than a preset threshold, if greater, execute S65a, if less than or equal to, execute S65b; S65a. Start the aperture tuning process, for example, set the aperture adjustable antenna to the first aperture state, the first aperture state is the aperture state corresponding to the minimum reflection coefficient among multiple aperture states, and continue to execute S66; S65b. There is no need to start antenna tuning, for example, restore the impedance tuning circuit to the first state; S66. Start the impedance tuning process, for example, set the impedance tuning circuit to the second state according to the minimum reflection coefficient corresponding to the first aperture state.

[0131] In an embodiment of the present application, by setting the impedance tuning circuit to a reference state, measuring the state parameters of the antenna in the reference state, and performing impedance matching based on the state parameters of the antenna, the storage overhead and tuning delay in the antenna tuning process can be greatly reduced, thereby reducing equipment costs while further improving user experience.

[0132] It should be noted that all relevant contents of each module or circuit involved in the above-mentioned device embodiment can be referred to in the relevant steps of the method embodiment, and the embodiment of the present application will not be repeated here.

[0133] In another embodiment of the present application, a computer-readable storage medium is provided, in which computer-executable instructions are stored. When a device (which may be a terminal or a chip, etc.) or a processor runs the computer-executable instructions, the device executes the antenna tuning method provided in the above method embodiment. The aforementioned computer-readable storage medium may be a non-perishable computer-readable storage medium, which may specifically include: a U disk, a mobile hard disk, a read-only memory, a random access memory, a magnetic disk or an optical disk, and other media that can store program codes.

[0134] In another embodiment of the present application, a computer program product is also provided, which includes computer execution instructions, and the computer execution instructions are stored in a computer-readable storage medium; at least one processor of the device can read the computer execution instructions from the computer-readable storage medium, and at least one processor executes the computer execution instructions to enable the device to use the antenna tuning method provided by the above method embodiment.

[0135] Finally, it should be noted that the above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An antenna tuning device, It is characterized in that The device comprises: An impedance tuning circuit coupled to an antenna, for providing impedance matching, the impedance tuning circuit having a reference state, the reference state being a preset state among a plurality of impedance tuning circuit states, a state parameter of the antenna being measured in the reference state, the impedance tuning circuit providing impedance matching based on the state parameter, and no impedance tuning is required in other states among the plurality of impedance tuning circuit states; wherein the absolute value of a port reflection parameter of the impedance tuning circuit in the reference state is less than a first threshold, and the absolute value of an inter-port transmission parameter is greater than a second threshold; The interface circuit is used to receive a first control signal, where the first control signal is used to put the impedance tuning circuit in a reference state.

2. The device according to claim 1, It is characterized in that The impedance tuning circuit includes an impedance tuner and a switch circuit connected in parallel, and the reference state is a state of the impedance tuning circuit when the switch circuit is closed.

3. The device according to claim 1, It is characterized in that The device also includes: A reflection coefficient detector is used to measure a state parameter of the antenna when the impedance tuning circuit is in the reference state.

4. The device according to claim 3, It is characterized in that The state parameter is a reflection coefficient or an impedance value.

5. The device according to claim 1, It is characterized in that The device also includes: A processor is coupled to the interface circuit and is used to output the first control signal.

6. The device according to claim 5, It is characterized in that The processor is further configured to: The control signal is output when a preset condition is met, and the preset condition includes any one of the following: a specified event occurs and a preset duration is reached.

7. The device according to claim 5, It is characterized in that The processor is a baseband processor, a radio frequency processor or a microprocessor.

8. The device according to claim 1, It is characterized in that The device also includes the antenna, which is an aperture-adjustable antenna; The aperture adjustable antenna is used to adjust the state parameters of the antenna to provide impedance matching.

9. The device according to claim 1, It is characterized in that The device also includes a radio frequency front-end module, the impedance tuning circuit is coupled between the radio frequency front-end module and the antenna, and the impedance matching is the impedance matching between the radio frequency front-end module and the antenna.

10. The device according to claim 9, It is characterized in that The radio frequency front-end module includes at least one of the following: a power amplifier, a filter, a low noise amplifier, and a duplexer.

11. The device according to any one of claims 1 to 10, It is characterized in that The device also includes: A radio frequency integrated circuit is used to provide digital-to-analog / analog-to-digital conversion during the measurement of the state parameters of the antenna.

12. The device according to claim 11, It is characterized in that The radio frequency integrated circuit comprises: an analog-to-digital / digital-to-analog converter, a low-pass filter, an up / down converter, and a driving amplifier.

13. An antenna tuning method, It is characterized in that The method comprises: Setting the impedance tuning circuit to a reference state, wherein the reference state is a preset state among a plurality of impedance tuning circuit states; wherein the absolute value of a port reflection parameter of the impedance tuning circuit in the reference state is less than a first threshold value, and the absolute value of an inter-port transmission parameter is greater than a second threshold value; Measuring a state parameter of the antenna in the reference state, the impedance tuning circuit providing impedance matching based on the state parameter, without performing impedance tuning in other states of the plurality of impedance tuning circuit states; Impedance tuning is performed based on the state parameters to achieve impedance matching.

14. The method according to claim 13, It is characterized in that The impedance tuning circuit includes an impedance tuner and a switch circuit connected in parallel, and the reference state is a state of the impedance tuning circuit when the switch circuit is closed.

15. The method according to claim 13, It is characterized in that Performing impedance tuning based on the state parameter to achieve impedance matching includes: Performing aperture tuning on the antenna based on the state parameter; The impedance tuning circuit is tuned based on the state parameters after the aperture is tuned to achieve impedance matching.

16. The method according to any one of claims 13 to 15, It is characterized in that The impedance matching is the impedance matching between the radio frequency front-end module and the antenna.

17. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores a computer program, and when the computer-readable storage medium is run on a device, the device executes the antenna tuning method according to any one of claims 13 to 16.

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