Impedance matching circuit and impedance matching method, radio frequency circuit, electronic device

Abstract

Provided are an impedance matching circuit and method, a radio frequency circuit, and an electronic device, and belong to the technical field of electronics. The impedance matching circuit comprises a transducer, a first adjustable circuit and a first switch circuit coupled between a first coil of the transducer and a first signal end, a second adjustable circuit and a second switch circuit coupled between a second coil of the transducer and a second signal end, and a control circuit coupled with the adjustable circuits and the switch circuits. The control circuit can adjust the working parameters of the adjustable circuits and the on-off states of the switch circuits based on the input impedance and the output impedance determined under different signal gain configurations, so as to achieve impedance matching. Therefore, the impedance matching circuit can achieve better impedance matching for different signal gain configurations, and has better flexibility in impedance matching.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of electronics, and in particular, to an impedance matching circuit and method, a radio frequency circuit, and an electronic device. BACKGROUND

[0002] A radio frequency (RF) circuit is a circuit for processing radio frequency signals, and is usually applied in an electronic device to be coupled with an antenna load included in the electronic device to realize a communication function.

[0003] In the related art, an RF circuit at least includes an impedance matching circuit, which generally includes a balance-unbalance (Balun) transformer. The Balun not only has a certain impedance matching capability, but also can complete the conversion of single-ended signals and differential signals, and provides support for the transmission and processing of signals in the RF circuit. In addition, for an RF circuit with multiple signal gain configurations, the Balun is generally designed with reference to the maximum signal gain configuration used by the RF circuit to achieve impedance matching.

[0004] However, since only the maximum signal gain configuration of the RF circuit is considered when designing the Balun, the Balun cannot achieve better impedance matching for different signal gain configurations, and the flexibility of impedance matching is poor. SUMMARY

[0005] An impedance matching circuit and method, a radio frequency circuit, and an electronic device are provided, which can solve the problem of poor flexibility of impedance matching in the related art. The technical solution is as follows:

[0006] In one aspect, an impedance matching circuit is provided, which includes:

[0007] a Balun transformer having a first coil and a second coil, and two ends of the first coil are coupled to two first signal terminals one by one, and two ends of the second coil are coupled to two second signal terminals one by one;

[0008] at least one first adjustable circuit and at least one first switch circuit corresponding to the at least one first adjustable circuit, each first adjustable circuit and the corresponding first switch circuit are connected in series between the two first signal terminals;

[0009] at least one second adjustable circuit and at least one second switch circuit corresponding to the at least one second adjustable circuit, each second adjustable circuit is connected in series between one second signal terminal and one end of the corresponding second coil, and each second switch circuit is connected between two ends of the corresponding second adjustable circuit;

[0010] a control circuit coupled with the at least one first adjustable circuit, the at least one first switch circuit, the at least one second adjustable circuit and the at least one second switch circuit respectively, and configured to adjust the working parameters of the at least one first adjustable circuit and the at least one second adjustable circuit, and adjust the on-off states of the at least one first switch circuit and the at least one second switch circuit, based on the input impedance and the output impedance of the impedance matching circuit under different signal gain configurations.

[0011] Optionally, each of the at least one first adjustable circuit and the at least one second adjustable circuit comprises at least one variable element, which is a variable inductor or a variable capacitor.

[0012] Furthermore, the types of the at least one variable element included in the at least one first adjustable circuit and the at least one variable element included in the at least one second adjustable circuit are the same.

[0013] Optionally, the impedance matching circuit comprises a plurality of first adjustable circuits and a plurality of second adjustable circuits.

[0014] Furthermore, the types of the at least one variable element included in the at least one first adjustable circuit and the at least one variable element included in the at least one second adjustable circuit are the same.

[0015] Optionally, the number of the first adjustable circuits included in the impedance matching circuit is the same as the number of the second adjustable circuits.

[0016] Furthermore, the number of the first switch circuits included in the impedance matching circuit is the same as the number of the second switch circuits.

[0017] Optionally, the impedance matching circuit comprises two first adjustable circuits and two second adjustable circuits.

[0018] Furthermore, the impedance matching circuit comprises two first switch circuits corresponding to the two first adjustable circuits respectively, and two second switch circuits corresponding to the two second adjustable circuits respectively.

[0019] Optionally, one of the two first adjustable circuits comprises a variable inductor, and the other first adjustable circuit comprises a variable capacitor.

[0020] Furthermore, one of the two second adjustable circuits comprises a variable inductor, and the other second adjustable circuit comprises a variable capacitor.

[0021] Optionally, each of the at least one first switch circuit and the at least one second switch circuit comprises a single-pole single-throw switch.

[0022] Optionally, the control circuit comprises a digital controller.

[0023] Optionally, the two first signal terminals are configured to receive two differential signals, and the center tap of the first coil is further coupled with a first reference power terminal.

[0024] The two second signal terminals are configured to receive two differential signals, and the center tap of the second coil is further coupled with a second reference power terminal; or, one of the two second signal terminals is configured to receive a single-ended signal, and the other second signal terminal is grounded, and each second adjustable circuit is connected in series between the second signal terminal receiving the single-ended signal and one end of the second coil coupled with the second signal terminal.

[0025] Optionally, the balun, the at least one first adjustable circuit, the at least one first switch circuit, the at least one second adjustable circuit, and the at least one second switch circuit are integrated or independent of each other.

[0026] In another aspect, an impedance matching method is provided, which is applied to a control circuit included in the impedance matching circuit of the above-mentioned aspect, and the method comprises:

[0027] determining target adjustment information based on input impedance and output impedance of the impedance matching circuit under a current signal gain configuration, the target adjustment information comprising working parameters of the at least one first adjustable circuit, working parameters of the at least one second adjustable circuit, on-off states of the at least one first switch circuit, and on-off states of the at least one second switch circuit;

[0028] adjusting the working parameters of the at least one first adjustable circuit and the working parameters of the at least one second adjustable circuit, and adjusting the on-off states of the at least one first switch circuit and the on-off states of the at least one second switch circuit based on the target adjustment information.

[0029] Optionally, the control circuit stores a corresponding relationship between impedance information and adjustment information under different signal gain configurations, and the impedance information comprises input impedance and output impedance.

[0030] The determining target adjustment information based on input impedance and output impedance of the impedance matching circuit under a current signal gain configuration comprises:

[0031] determining target adjustment information from the adjustment information included in the corresponding relationship based on input impedance and output impedance of the impedance matching circuit under a current signal gain configuration.

[0032] Optionally, each of the at least one first adjustable circuit and the at least one second adjustable circuit comprises at least one variable inductance, and the working parameters of the at least one first adjustable circuit and the at least one second adjustable circuit in the target adjustment information each comprise an inductance value.

[0033] Or, each of the at least one first adjustable circuit and the at least one second adjustable circuit comprises at least one variable capacitance, and the working parameters of the at least one first adjustable circuit and the at least one second adjustable circuit in the target adjustment information each comprise a capacitance value.

[0034] In another aspect, an RF circuit is provided, which comprises a pre-stage circuit, a post-stage circuit, and the impedance matching circuit as described in the above aspect.

[0035] The pre-stage circuit is coupled to a first coil of a transducer in the impedance matching circuit through two first signal terminals, and the post-stage circuit is coupled to a second coil of the transducer through at least one of two second signal terminals, and the pre-stage circuit and the post-stage circuit are configured to perform signal transmission through the impedance matching circuit.

[0036] In another aspect, an electronic device is provided, which comprises an antenna load and the RF circuit as described in the above aspect.

[0037] The RF circuit is coupled to the antenna load and configured to perform signal transmission with the antenna load.

[0038] In summary, the technical solutions provided by the embodiments of the present disclosure can bring at least the following beneficial effects:

[0039] An impedance matching circuit and an impedance matching method, an RF circuit, and an electronic device are provided. The impedance matching circuit comprises a transducer, a first adjustable circuit and a first switch circuit coupled between a first coil of the transducer and a first signal terminal, a second adjustable circuit and a second switch circuit coupled between a second coil of the transducer and a second signal terminal, and a control circuit coupled to the adjustable circuits and the switch circuits. Since the control circuit can adjust the working parameters of the adjustable circuits and the on-off states of the switch circuits based on the input impedance and the output impedance determined under different signal gain configurations, so as to achieve impedance matching, the impedance matching circuit can achieve better impedance matching for different signal gain configurations, and has better flexibility in impedance matching. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to make the technical solutions in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0041] Figure 1 is a structural schematic diagram of an impedance matching circuit provided by an embodiment of the present disclosure;

[0042] Figure 2 is a structural schematic diagram of another impedance matching circuit provided by an embodiment of the present disclosure;

[0043] Figure 3 is a structural schematic diagram of still another impedance matching circuit provided by an embodiment of the present disclosure;

[0044] Figure 4 is a flowchart of an impedance matching method provided by an embodiment of the present disclosure;

[0045] Figure 5 is a structural schematic diagram of a radio frequency circuit provided by an embodiment of the present disclosure;

[0046] Figure 6 is a structural schematic diagram of an electronic device provided by an embodiment of the present disclosure;

[0047] Figure 7 is a structural schematic diagram of another electronic device provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0048] In order to make the technical solutions in the embodiments of the present application clearer, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0049] Figure 1 is a structural schematic diagram of an impedance matching circuit provided by an embodiment of the present disclosure. As shown in Figure 1 , the impedance matching circuit 00 includes a balun 01, i.e., a balanced-unbalanced converter.

[0050] The balun 01 has a first coil L1 and a second coil L2, and two ends of the first coil L1 are coupled (i.e., electrically connected) to two first signal ends V1 one by one, and two ends of the second coil L2 are coupled to two second signal ends V2 one by one.

[0051] Taking the first coil L1 as an example, referring to Figure 1It can be known that the one-to-one coupling can mean that in two ends of the first coil L1, one end is coupled with one of the two first signal ends V1, and the other end is coupled with the other of the two first signal ends V1. The coupling of the second coil L2 and the second signal end V2 is the same. For distinction, the two first signal ends V1 are respectively marked as V1-1 and V1-2 in the figure, and the two second signal ends V2 are respectively marked as V2-1 and V2-2.

[0052] Optionally, in the first coil L1 and the second coil L2, one coil can be a primary coil, and the other coil can be a secondary coil correspondingly. The signal end coupled with the primary coil can be called an input signal end input, and the signal end coupled with the secondary coil can be called an output signal end output. For example, the following embodiments of the present disclosure take the first coil L1 as the primary coil, and the two first signal ends V1 as two input signal ends input1 and input2 as an example for description.

[0053] Continuing to refer to Figure 1 The impedance matching circuit 00 further includes at least one first adjustable circuit 02 and at least one first switch circuit 03 corresponding to the at least one first adjustable circuit 02.

[0054] Each first adjustable circuit 02 and the corresponding first switch circuit 03 are connected in series between the two first signal ends V1. That is, referring to Figure 1 Each first adjustable circuit 02 can be coupled with one of the two first signal ends V1 (for example, V1-1) and the corresponding first switch circuit 03 respectively, and each first switch circuit 03 is further coupled with the other of the two first signal ends V1 (for example, V1-2). The coupling mode can also be understood as that each first adjustable circuit 02 is coupled between the two first signal ends V1 through the corresponding first switch circuit 03. The at least one first adjustable circuit 02 can be considered as an adjusting circuit arranged on one side of the first coil L1.

[0055] Continuing to refer to Figure 1 The impedance matching circuit 00 further includes at least one second adjustable circuit 04 and at least one second switch circuit 05 corresponding to the at least one second adjustable circuit 04.

[0056] Each second adjustable circuit 04 is connected in series between one second signal end V2 (for example, V2-1) and one end of the corresponding coupled second coil L2, and each second switch circuit 05 is connected between two ends of the corresponding second adjustable circuit 04. That is, referring to Figure 1A plurality of second adjustable circuits 04 can be connected in series between the second signal end V2-1 and one end of the second coil L2 coupled thereto, and a second switch circuit 05 corresponding to each second adjustable circuit 04 can be connected in parallel with the second adjustable circuit 04.

[0057] With reference to the foregoing description Figure 1 The impedance matching circuit 00 further comprises a control circuit 06 coupled with the at least one first adjustable circuit 02, the at least one first switch circuit 03, the at least one second adjustable circuit 04 and the at least one second switch circuit 05, respectively. The coupling of the control circuit 06 with one first adjustable circuit 02, one first switch circuit 03, one second adjustable circuit 04 and one second switch circuit 05 is only schematically shown in the figure. The control circuit 06 is configured to adjust the working parameters of the at least one first adjustable circuit 02 and the at least one second adjustable circuit 04, and to adjust the on-off states of the at least one first switch circuit 03 and the at least one second switch circuit 05, based on the input impedance and the output impedance of the impedance matching circuit 00 under different signal gain configurations.

[0058] Optionally, the impedance matching circuit 00 can be applied in a radio frequency circuit, such as a radio frequency integrated circuit (RFIC). In the RFIC, a plurality of power amplifiers (PAs) can be connected in parallel between the two first signal ends V1. When the radio frequency circuit is in operation, one or more PAs can be controlled to be connected with the signal ends to realize signal amplification. Correspondingly, different signal gains can be related to the number of connected PAs, i.e., determined by the amplification capability. The control circuit 06 can determine the required input impedance and output impedance (which can be collectively referred to as impedance information) based on different signal gain configurations, i.e., different signal gain configurations can correspond to different impedance information, and the impedance information can also be determined under the condition of signal gain configuration determination. The input impedance can refer to the impedance between the two primary coils, and the output impedance can refer to the impedance between the two secondary coils. Correspondingly, the impedance can be adjusted by adjusting the working parameters (such as inductance value) between the two coils to achieve impedance matching.

[0059] At present, a Balun is generally designed according to the maximum signal gain configuration among a plurality of signal gain configurations. The design process of the Balun is also relatively complex. For example, the desired inductance value is generally obtained by simulation first, then the Balun layout is drawn according to the simulation data, and then it is verified whether the impedance characteristics meet the design requirements. Then, a suitable Balun can be designed based on the verification results through repeated iterations, which is a large amount of work and takes a long time. Moreover, the designed Balun cannot achieve better impedance matching for different signal gain configurations.

[0060] In the embodiments of the present disclosure, the Balun can be regarded as a black box, i.e., without designing the Balun as in the above embodiments, without considering the parameter characteristics of the Balun itself, and by setting adjustable circuits (e.g., variable inductors) and switch circuits on the two coil sides of the Balun respectively, and by adjusting the working parameters (e.g., the inductance values of the variable inductors) of the adjustable circuits and the on-off states of the switch circuits to adjust the impedance, the purpose of impedance matching can be achieved. In this way, not only better impedance matching can be achieved for different signal gain configurations, but also the design method is simplified, the workload is reduced, and the design time is shortened because the Balun does not need to be designed specifically.

[0061] For example, taking a first switch circuit 03 as an example, when the control circuit 06 controls a first switch circuit 03 to be turned on, the first adjustable circuit 02 corresponding to the first switch circuit 03 can be connected between the two first signal terminals V1-1 and V1-2. On this basis, the working parameters (e.g., the inductance values of the variable inductors) of the first adjustable circuit 02 connected between the two first signal terminals V1-1 and V1-2 can be adjusted to achieve the purpose of adjusting the impedance on the side of the first coil L1. When the control circuit 06 controls a first switch circuit 03 to be turned off, the first adjustable circuit 02 corresponding to the first switch circuit 03 will not be connected between the two first signal terminals V1-1 and V1-2.

[0062] For example, taking a second switch circuit 05 as an example, when the control circuit 06 controls a second switch circuit 05 to be turned off, the second signal terminal V2-1 and one end of the second coil L2 can be connected through the second adjustable circuit 04 corresponding to the second switch circuit 05, i.e., the second adjustable circuit 04 corresponding to the second switch circuit 05 can be connected between the second signal terminal V2-1 and one end of the second coil L2. On this basis, the working parameters of the second adjustable circuit 04 connected between the second signal terminal V2-1 and the second coil L2 can be adjusted to achieve the purpose of adjusting the impedance on the side of the second coil L2. When the control circuit 06 controls a second switch circuit 05 to be turned on, the second signal terminal V2-1 and one end of the second coil L2 can be directly connected through the second switch circuit 05, i.e., the second adjustable circuit 04 corresponding to the second switch circuit 05 will not be connected between the second signal terminal V2-1 and one end of the second coil L2.

[0063] It should be noted that, as described in the above embodiments, the adjustment generally refers to the adjustment circuit corresponding to the conducting switch circuit. Therefore, in some embodiments, the adjustment may involve adjusting the operating parameters of at least one first adjustment circuit 02 and / or at least one second adjustment circuit 04. Based on the inclusion of multiple first adjustable circuits 02, the adjustment may involve adjusting the operating parameters of one or more first adjustable circuits 02. Similarly, based on the inclusion of multiple second adjustable circuits 04, the adjustment may involve adjusting the operating parameters of one or more second adjustable circuits 04. This disclosure does not limit the number of objects to be adjusted.

[0064] In summary, this disclosure provides an impedance matching circuit. The impedance matching circuit includes a balance switch, a first adjustable circuit and a first switching circuit coupled between a first coil and a first signal terminal of the balance switch, a second adjustable circuit and a second switching circuit coupled between a second coil and a second signal terminal of the balance switch, and a control circuit coupled to the adjustable circuit and the switching circuit. Because the control circuit can adjust the operating parameters of the adjustable circuit and the on / off state of the switching circuit based on the input and output impedances determined under different signal gain configurations to achieve impedance matching, this impedance matching circuit can achieve optimal impedance matching for different signal gain configurations, and offers good flexibility in impedance matching.

[0065] Optionally, in the impedance matching circuit 00 provided in this embodiment, the two first signal terminals V1 coupled to the first coil L1 of the balancer 01 can be used to receive two differential signals. Correspondingly, in conjunction with... Figure 1 It can also be seen that the center tap of the first coil L1 can be coupled to the first reference power supply terminal Vcm1.

[0066] The two second signal terminals V2, coupled to the second coil L2 of the weighing device 01, can be used to receive two differential signals. Correspondingly, combined with... Figure 1 It can also be seen that the center tap of the second coil L2 is also coupled to the second reference power supply terminal Vcm2. Based on this embodiment, if multiple second adjustable circuits 04 are included, then as follows... Figure 1 As shown, all the second adjustable circuits 04 can be connected in series between the same second signal terminal V2 (e.g., V2-1) and one end of the corresponding coupled second coil L2. Alternatively, in some other embodiments, a portion of the multiple second adjustable circuits 04 can be connected in series between one second signal terminal V2 (e.g., V2-1) and one end of the corresponding coupled second coil L2, while another portion of the second adjustable circuits 04 can be connected in series between another second signal terminal V2 (e.g., V2-2) and one end of the corresponding coupled second coil L2.

[0067] Or, such as Figure 2As shown, among the two second signal terminals V2, one second signal terminal V2 (e.g., V2-1) can be used to receive a single-ended signal, and the other second signal terminal V2 (e.g., V2-2) can be grounded, i.e., coupled to the ground terminal GND. It should be noted that each second adjustable circuit 04 described in the above embodiment can be connected in series between the second signal terminal V2 (e.g., V2-1) receiving a single-ended signal and one end of the corresponding second coil L2.

[0068] The two differential signals refer to a pair of balanced signals, and the signal amplitudes of the pair of balanced signals are the same, and the signal phases are opposite. The single-ended signal is relative to the differential signal and is an unbalanced signal. The balun 01 with the balanced-unbalanced conversion function can realize mutual conversion between the single-ended signal and the differential signal, i.e., converting the single-ended signal into the differential signal, or converting the differential signal into the single-ended signal, or converting the differential signal into the differential signal. For the balun 01 with the balanced-unbalanced conversion function, the single-ended signal and the differential signal can be converted into each other. Figure 1 As shown in the structure, the first coil L1 and the second coil L2 are both differential signals. For the structure shown in Figure 2 As shown in the structure, the first coil L1 is a differential signal, and the second coil L2 is a single-ended signal. Because the differential signal has strong common-mode interference resistance and is suitable for long-distance transmission, when applied to the RFIC, the internal signal transmission is performed in a differential manner.

[0069] Optionally, taking the structure shown in Figure 1 As shown in the structure, the first coil L1 and the second coil L2 are both differential signals. For the structure shown in Figure 3 As shown in another structure of the impedance matching circuit, in the embodiment of the present disclosure, each adjustable circuit in the at least one first adjustable circuit 02 and the at least one second adjustable circuit 04 can include at least one variable element, which is a variable inductor L0 or a variable capacitor C0. That is, each adjustable circuit can include at least one variable inductor L0 or at least one variable capacitor C0.

[0070] For the variable inductor L0, the working parameter is the inductance value. For the variable capacitor C0, the working parameter is the capacitance value. The inductance value of the variable inductor L0 is adjustable, and can process the impedance matching of inductive signals; the capacitance value of the variable capacitor C0 is adjustable, and can process the impedance matching of capacitive signals.

[0071] And, the type of at least one variable element included in the at least one first adjustable circuit 02 and the at least one variable element included in the at least one second adjustable circuit 04 can be the same. That is, under the premise that the at least one first adjustable circuit 02 includes a variable inductance L0, the at least one second adjustable circuit 04 also includes at least a variable inductance L0. Similarly, under the premise that the at least one first adjustable circuit 02 includes a variable capacitance C0, the at least one second adjustable circuit 04 also includes at least a variable capacitance C0. Since the signal on one side is an inductive signal, the signal processed on the other side is also an inductive signal, so by setting the type of at least one variable element to be the same, the reliability of impedance matching can be ensured.

[0072] And, continuing to refer to Figure 3 It can be seen that, under the premise that the impedance matching circuit 00 includes a plurality of first adjustable circuits 02 and a plurality of second adjustable circuits 04, the type of the variable element included in at least two first adjustable circuits 02 can be different, and the type of the variable element included in at least two second adjustable circuits 04 can be different. That is, among the plurality of first adjustable circuits 02, at least one first adjustable circuit 02 includes a variable inductance L0, and at least one first adjustable circuit 02 includes a variable capacitance C0. The second adjustable circuit 04 is similar and will not be repeated. By setting both a variable inductance L0 and a variable capacitance C0, compatible processing of inductive signals and capacitive signals can be achieved, the scope of application is wider, and the versatility is stronger.

[0073] Optionally, continuing to refer to Figure 3 It can be seen that the number of first adjustable circuits 02 included in the impedance matching circuit 00 and the number of second adjustable circuits 04 can be the same. Correspondingly, the number of first switch circuits 03 included in the impedance matching circuit 00 and the number of second switch circuits 05 can be the same. In this way, better impedance matching can be further achieved.

[0074] For example, Figure 3 The impedance matching circuit 00 shown includes two first adjustable circuits 02 and two second adjustable circuits 04. And, it includes two first switch circuits 03 corresponding to the two first adjustable circuits 02, and two second switch circuits 05 corresponding to the two second adjustable circuits 04.

[0075] And, continuing to refer to Figure 3 It can be seen that one of the two first adjustable circuits 02 shown includes a variable inductance L0, and the other first adjustable circuit 02 includes a variable capacitance C0. And, one of the two second adjustable circuits 04 includes a variable inductance L0, and the other second adjustable circuit 04 includes a variable capacitance C0.

[0076] In Figure 3It can be seen that the adjustable circuit 02 and the adjustable circuit 04 can be the same in number of variable elements, the same in number of variable inductors L0, and the same in number of variable capacitors C0.

[0077] Optionally, continuing to refer to Figure 3 It can be seen that each of the at least one first switch circuit 03 and the at least one second switch circuit 05 can include a single-pole single-throw switch K0. Of course, in some embodiments, each of the switch circuits can also include other types of switches such as switching transistors.

[0078] It should be noted that, for the sake of distinction, Figure 3 The variable inductor L0 included in one of the first adjustable circuits 02 is identified as L0-1, and the variable inductor L0 included in one of the second adjustable circuits 04 is identified as L0-2. The variable capacitor C0 included in another of the first adjustable circuits 02 is identified as C0-1, and the variable capacitor C0 included in another of the second adjustable circuits 04 is identified as C0-2. The single-pole single-throw switch K0 corresponding to the variable inductor L0-1 is identified as K0-1, the single-pole single-throw switch K0 corresponding to the variable capacitor C0-1 is identified as K0-2, the single-pole single-throw switch K0 corresponding to the variable inductor L0-2 is identified as K0-3, and the single-pole single-throw switch K0 corresponding to the variable capacitor C0-2 is identified as K0-4.

[0079] Optionally, continuing to refer to Figure 3 It can be seen that the control circuit 06 according to the embodiments of the present disclosure can include a digital controller (DC).

[0080] The digital controller can be coupled to the variable inductor L0-1, the variable inductor L0-2, the variable capacitor C0-1, the variable capacitor C0-2, the single-pole single-throw switch K0-1, the single-pole single-throw switch K0-2, the single-pole single-throw switch K0-3, and the single-pole single-throw switch K0-4 through six pins, respectively, to control the single-pole single-throw switches K0 to be turned on or turned off, and to adjust the inductance value of the variable inductors L0 and the capacitance value of the variable capacitors C0.

[0081] It should be noted that, for the scenario of applying the impedance matching circuit to a radio frequency integrated circuit (RFIC), since the RFIC is generally an analog circuit and the digital controller DC is a digital circuit, in order to ensure the working reliability of the digital circuit and the analog circuit, the digital controller DC and other parts (such as the adjustable circuit, the balun, and the switch circuit) of the impedance matching circuit can be independently arranged, and the embodiments of the present disclosure only schematically illustrate that the impedance matching circuit can include the digital controller DC, but are not used to represent integrated arrangement.

[0082] In addition, the balun 01, the at least one first adjustable circuit 02, the at least one first switch circuit 03, the at least one second adjustable circuit 04, and the at least one second switch circuit 05 can be integrated. For example, all the adjustable circuits in the impedance matching circuit, all the switch circuits, and the balun 01 can be integrated on a system on chip (SOC). When applied to an RFIC, it means that the RFIC is integrated on the SOC. Alternatively, the balun 01, the at least one first adjustable circuit 02, the at least one first switch circuit 03, the at least one second adjustable circuit 04, and the at least one second switch circuit 05 can be independent of each other. For example, the balun 01 can be integrated on the SOC, and the adjustable circuits and the switch circuits can be implemented by off-chip components. This arrangement mainly considers that the chip area is relatively limited.

[0083] Based on the above description, it can be known that the embodiment of the present disclosure provides an impedance matching circuit including a balun, a variable inductor, a variable capacitor, a switching switch, and a control circuit. The balun can reuse a mature design without secondary iterative design, and can be used in different impedance matching requirements only by adjusting the inductance value and / or the capacitance value. Not only the design workload is greatly reduced and the design efficiency is improved, but also better impedance matching can be achieved under different signal gain configurations.

[0084] In summary, the embodiment of the present disclosure provides an impedance matching circuit. The impedance matching circuit includes a balun, a first adjustable circuit and a first switch circuit coupled between a first coil of the balun and a first signal terminal, a second adjustable circuit and a second switch circuit coupled between a second coil of the balun and a second signal terminal, and a control circuit coupled with the adjustable circuits and the switch circuits. Since the control circuit can adjust the working parameters of the adjustable circuits and the on-off states of the switch circuits based on the input impedance and the output impedance determined under different signal gain configurations to achieve impedance matching, the impedance matching circuit can achieve better impedance matching for different signal gain configurations, and the flexibility of impedance matching is better.

[0085] Figure 4 The present disclosure provides an impedance matching method. The method is applied to the impedance matching circuit as described in any one of Figure 1 to Figure 3 The control circuit 06 included in any one of the impedance matching circuits. As shown in Figure 4 The method includes the following steps.

[0086] In step 401, target adjustment information is determined based on the input impedance and the output impedance of the impedance matching circuit under the current signal gain configuration.

[0087] The target adjustment information includes working parameters of the at least one first adjustable circuit, working parameters of the at least one second adjustable circuit, on-off states of the at least one first switch circuit, and on-off states of the at least one second switch circuit in the impedance matching circuit.

[0088] At step 402, based on the target adjustment information, the working parameters of the at least one first adjustable circuit and the working parameters of the at least one second adjustable circuit are adjusted, and the on-off states of the at least one first switch circuit and the on-off states of the at least one second switch circuit are adjusted.

[0089] Optionally, as described in the above embodiments, each of the at least one first adjustable circuit and the at least one second adjustable circuit includes at least one variable inductor. Correspondingly, the working parameters of the at least one first adjustable circuit and the working parameters of the at least one second adjustable circuit in the target adjustment information can each include an inductance value. Alternatively, each of the at least one first adjustable circuit and the at least one second adjustable circuit includes at least one variable capacitor. Correspondingly, the working parameters of the at least one first adjustable circuit and the working parameters of the at least one second adjustable circuit in the target adjustment information each include a capacitance value.

[0090] Optionally, the control circuit can pre-store a correspondence between impedance information and adjustment information under different signal gain configurations, the impedance information including input impedance and output impedance. For example, the correspondence can be stored in the form of a table. On this basis, the above step 401, i.e., determining the target adjustment information based on the input impedance and the output impedance of the impedance matching circuit under the current signal gain configuration, can include:

[0091] Based on the input impedance and the output impedance of the impedance matching circuit under the current signal gain configuration, the target adjustment information is determined from the adjustment information included in the correspondence. For example, based on the correspondence in the form of a table, the target adjustment information can be directly found in the correspondence.

[0092] Optionally, taking the structure shown in FIG. 8 as an example, the design of the above correspondence is described as follows: Figure 3

[0093] ​Before the impedance matching circuit leaves the factory, first, a user (such as an engineer) can determine the input impedance and the output impedance across the primary coil and the secondary coil in the Balun under different signal gain configurations. Then, the user can further calculate and draw a Smith chart to adjust the inductance value and the capacitance value, determine the working parameters of the variable elements such as the variable inductance L0-1, the variable inductance L0-2, the variable capacitance C0-1, the variable capacitance C0-2, and determine the switch elements required to be turned on and turned off in the single-pole single-throw switch K0-1, the single-pole single-throw switch K0-2, the single-pole single-throw switch K0-3, and the single-pole single-throw switch K0-4, that is, determine the unused single-pole single-throw switches that need to be shielded. Finally, the user can store the impedance information and the adjustment information under different signal gain configurations in the control circuit 06 in a one-to-one correspondence. After that, the control circuit 06 can be linked with the signal gain configuration under different scenarios, and adaptively match the circuit when the signal gain configuration changes, that is, adjust the working parameters of the at least one first adjustable circuit and the working parameters of the at least one second adjustable circuit, and adjust the on-off state of the at least one first switch circuit and the on-off state of the at least one second switch circuit based on the determined target adjustment information when the signal gain configuration changes.

[0094] In summary, the embodiments of the present disclosure provide an impedance matching method. In the method, the control circuit in the impedance matching circuit can determine the target adjustment information based on the input impedance and the output impedance under the current signal gain configuration, that is, determine the working parameters of the at least one first adjustable circuit, the working parameters of the at least one second adjustable circuit, the on-off state of the at least one first switch circuit, and the on-off state of the at least one second switch circuit, and can adjust the working parameters of the at least one first adjustable circuit and the working parameters of the at least one second adjustable circuit, and adjust the on-off state of the at least one first switch circuit and the on-off state of the at least one second switch circuit based on the target adjustment information. In this way, better impedance matching can be achieved for different signal gain configurations, and the flexibility of impedance matching is better.

[0095] Figure 5 is a structural schematic diagram of a radio frequency circuit provided by the embodiments of the present disclosure. As shown in Figure 5 , the radio frequency circuit can include a front-end circuit 10, a back-end circuit 20, and an impedance matching circuit 00 as shown in Figure 1 to Figure 3 any of them.

[0096] It can be seen from Figure 3 and Figure 5 that the front-end circuit 10 can be coupled to the first coil L1 of the balun 10 through two first signal ends V1, and the back-end circuit 20 can be coupled to the second coil L2 of the balun 10 through at least one of the two second signal ends V2.

[0097] As shown in Figure 5 , under the premise that two second signal terminals V2 receive two differential signals, the post-stage circuit 20 can be coupled with the second coil L2 of the balun 10 through the two second signal terminals V2. Under the premise that one of the two second signal terminals V2 receives a single-ended signal and the other second signal terminal V2 is grounded, the post-stage circuit 20 can be coupled with the second coil L2 of the balun 10 through the second signal terminal V2 receiving the single-ended signal.

[0098] On the basis of the above coupling, the pre-stage circuit 10 and the post-stage circuit 20 can be used for signal transmission through the impedance matching circuit 00. The signal here can be a single-ended signal and / or two differential signals.

[0099] Figure 6 is a structural schematic diagram of a radio frequency circuit provided by an embodiment of the present disclosure. As shown in Figure 6 , the electronic device can include an antenna load 100 and a radio frequency circuit 000 as shown in Figure 5 .

[0100] The radio frequency circuit 000 is coupled with the antenna load 100 and is used for signal transmission with the antenna load 100, thereby realizing a communication function.

[0101] Optionally, continuing to refer to Figure 7 , another structural schematic diagram of an electronic device is shown. In combination with Figure 7 , it can be seen that the electronic device shown includes two baluns. Among them, one balun Balun as shown in Figure 3 Balun 01 can be an internal balun Internal Balun. The other balun Balun has one of its two second signal terminals V2 grounded, and the other balun Balun can also be referred to as an output balun Output Balun. Moreover, the other balun 01 can be divided into the post-stage circuit 20 included in the radio frequency circuit 000. Continuing to refer to Figure 7 , it can be seen that the antenna load 100 can be coupled in the other balun 01 on the other second signal terminal V2 that is not grounded. For the other balun 01, reference can also be made to the above Figure 3 The variable inductance, the variable capacitance and the single-pole single-throw switch are respectively added on each side of the two coils, thereby realizing flexible adjustment of impedance matching.

[0102] In addition, referring to Figure 7It can also be seen that in each of the two Baluns, the first coil L1 side of each Balun can be coupled with multiple parallel amplifiers PA, respectively identified as PAD and PA. For each Balun, the signal gain configuration under impedance matching is related to the number of coupled amplifiers. For example, Figure 3 Each Balun is shown to be coupled with 3 parallel amplifiers on one side. In addition, the first amplifier PAD can also receive two signals (Vin_P and Vin_N) with opposite phases. Figure 7 The structure shown can be considered as converting the two signals Vin_P and Vin_N into two differential signals through the Internal Balun after amplification, and then transmitting to the antenna load 100 through the Output Balun after amplification.

[0103] Optionally, the electronic device described in the embodiments of the present disclosure can be a display device including a display panel. For example, the display device can be a mobile phone, a tablet computer, a flexible display device, a television, a display, or any product or component with display function.

[0104] The terms used in the embodiments of the present disclosure are only used to explain the embodiments of the present disclosure, and are not intended to limit the present disclosure. Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood as the general meaning understood by those skilled in the art to which the present disclosure belongs.

[0105] As used in the present patent application specification and claims, "first", "second", or "third" and similar words do not indicate any order, number or importance, but are only used to distinguish different components.

[0106] Similarly, "one" or "a" and similar words do not indicate a quantity limitation, but indicate the existence of at least one.

[0107] "Include" or "contain" and similar words mean that the elements or objects appearing before "include" or "contain" cover the elements or objects listed after "include" or "contain" and their equivalents, and do not exclude other elements or objects.

[0108] "Up", "down", "left" or "right" and the like are only used to represent relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly. "Connected" or "coupled" means electrical connection.

[0109] "and / or", means that there can be three kinds of relationship, for example, A and / or B, can represent: A alone, A and B exist at the same time, B alone, the three cases. The character " / " generally represents the front and rear associated objects are a kind of "or" relationship.

[0110] The above only describes optional embodiments of the present disclosure, and is not intended to limit the present disclosure. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. An impedance matching circuit, characterized in that, The impedance matching circuit includes: The weighing instrument (01) has a first coil (L1) and a second coil (L2), and the two ends of the first coil (L1) are coupled to two first signal terminals (V1) in a one-to-one correspondence, and the two ends of the second coil (L2) are coupled to two second signal terminals (V2) in a one-to-one correspondence; and multiple amplifiers are connected in parallel between the two first signal terminals (V1). At least one first adjustable circuit (02), and at least one first switching circuit (03) corresponding to the at least one first adjustable circuit (02), wherein each first adjustable circuit (02) and the corresponding first switching circuit (03) are connected in series between the two first signal terminals (V1); At least one second adjustable circuit (04), and at least one second switching circuit (05) corresponding to the at least one second adjustable circuit (04), each second adjustable circuit (04) being connected in series between a second signal terminal (V2) and one end of the corresponding coupled second coil (L2), and each second switching circuit (05) being connected to both ends of the corresponding second adjustable circuit (04); The control circuit (06) is coupled to the at least one first adjustable circuit (02), the at least one first switching circuit (03), the at least one second adjustable circuit (04), and the at least one second switching circuit (05), respectively. The control circuit (06) stores the correspondence between impedance information and adjustment information under different signal gain configurations. The impedance information includes input impedance and output impedance. During the operation of the impedance matching circuit, the control circuit (06) is used to: The current signal gain configuration of the impedance matching circuit is determined based on the number of amplifiers among the plurality of amplifiers that are connected to the two first signal terminals (V1). Based on the input impedance and output impedance of the impedance matching circuit under the current signal gain configuration, target adjustment information is determined from the adjustment information included in the correspondence, wherein the target adjustment information includes the operating parameters of the at least one first adjustable circuit, the operating parameters of the at least one second adjustable circuit, the on / off state of the at least one first switching circuit, and the on / off state of the at least one second switching circuit. Based on the target adjustment information, the on / off state of the at least one first switching circuit (03) and the on / off state of the at least one second switching circuit (05) are adjusted, and the operating parameters of the at least one first adjustable circuit (02) corresponding to the at least one first switching circuit (03) that is turned on and the operating parameters of the at least one second adjustable circuit (04) corresponding to the at least one second switching circuit (05) that is turned on are adjusted, so as to adjust the impedance at both ends of the first coil (L1) and the impedance at both ends of the second coil (L2) so that impedance matching of the input impedance and the output impedance is achieved under the current signal gain configuration.

2. The impedance matching circuit according to claim 1, characterized in that, Each of the at least one first adjustable circuit (02) and the at least one second adjustable circuit (04) includes at least one variable element, which is a variable inductor (L0) or a variable capacitor (C0). Furthermore, at least one of the variable elements included in the at least one first adjustable circuit (02) and the at least one second adjustable circuit (04) is of the same type.

3. The impedance matching circuit according to claim 2, characterized in that, The impedance matching circuit includes: a plurality of first adjustable circuits (02) and a plurality of second adjustable circuits (04); Furthermore, at least two of the first adjustable circuits (02) include variable elements of different types, and at least two of the second adjustable circuits (04) include variable elements of different types.

4. The impedance matching circuit according to any one of claims 1 to 3, characterized in that, The impedance matching circuit includes the same number of first adjustable circuits (02) as the number of second adjustable circuits (04); Furthermore, the impedance matching circuit includes the same number of first switching circuits (03) as the number of second switching circuits (05).

5. The impedance matching circuit according to claim 4, characterized in that, The impedance matching circuit includes: two first adjustable circuits (02) and two second adjustable circuits (04); And, two first switching circuits (03) corresponding one-to-one with the two first adjustable circuits (02), and two second switching circuits (05) corresponding one-to-one with the two second adjustable circuits (04).

6. The impedance matching circuit according to claim 5, characterized in that, One of the two first adjustable circuits (02) includes a variable inductor (L0), and the other first adjustable circuit (02) includes a variable capacitor (C0). In addition, one of the two second adjustable circuits (04) includes a variable inductor (L0), and the other second adjustable circuit (04) includes a variable capacitor (C0).

7. The impedance matching circuit according to any one of claims 1 to 3, characterized in that, Each of the at least one first switching circuit (03) and the at least one second switching circuit (05) includes a single-pole single-throw switch (K0).

8. The impedance matching circuit according to any one of claims 1 to 3, characterized in that, The control circuit (06) includes: a digital controller.

9. The impedance matching circuit according to any one of claims 1 to 3, characterized in that, The two first signal terminals (V1) are used to receive two differential signals, and the center tap of the first coil (L1) is also coupled to the first reference power supply terminal (Vcm1). The two second signal terminals (V2) are used to receive two differential signals, and the center tap of the second coil (L2) is also coupled to the second reference power supply terminal (Vcm2); or, of the two second signal terminals (V2), one second signal terminal (V2) is used to receive one single-ended signal, and the other second signal terminal (V2) is grounded, and each of the second adjustable circuits (04) is connected in series between the second signal terminal (V2) that receives one single-ended signal and one end of the correspondingly coupled second coil (L2).

10. The impedance matching circuit according to any one of claims 1 to 3, characterized in that, The weighing device (01), the at least one first adjustable circuit (02), the at least one first switching circuit (03), the at least one second adjustable circuit (04), and the at least one second switching circuit (05) are integrated or independent of each other.

11. An impedance matching method, characterized in that, The method, applied in the control circuit included in any one of the impedance matching circuits as described in claims 1 to 10, comprises: The target adjustment information is determined based on the input impedance and output impedance of the impedance matching circuit under the current signal gain configuration. The target adjustment information includes the operating parameters of at least one first adjustable circuit, the operating parameters of at least one second adjustable circuit, the on / off state of at least one first switching circuit, and the on / off state of at least one second switching circuit in the impedance matching circuit. Based on the target adjustment information, the operating parameters of the at least one first adjustable circuit and the operating parameters of the at least one second adjustable circuit are adjusted, and the on / off states of the at least one first switching circuit and the at least one second switching circuit are adjusted.

12. The method according to claim 11, characterized in that, In the at least one first adjustable circuit and the at least one second adjustable circuit, each adjustable circuit includes at least one variable inductor, and in the target adjustment information, the operating parameters of the at least one first adjustable circuit and the operating parameters of the at least one second adjustable circuit both include an inductance value. Alternatively, in the at least one first adjustable circuit and the at least one second adjustable circuit, each adjustable circuit includes at least one variable capacitor, and in the target adjustment information, the operating parameters of the at least one first adjustable circuit and the operating parameters of the at least one second adjustable circuit both include a capacitance value.

13. A radio frequency circuit, characterized in that, The radio frequency circuit includes: a pre-stage circuit (10), a post-stage circuit (20), and an impedance matching circuit (00) as described in any one of claims 1 to 10. The pre-stage circuit (10) is coupled to the first coil (L1) of the balance changer (10) in the impedance matching circuit (00) through two first signal terminals (V1), and the post-stage circuit (20) is coupled to the second coil (L2) of the balance changer (10) through at least one of two second signal terminals (V2). The pre-stage circuit (10) and the post-stage circuit (20) are used for signal transmission through the impedance matching circuit (00).

14. An electronic device, characterized in that, The electronic device includes: an antenna load (100) and a radio frequency circuit (000) as described in claim 13. The radio frequency circuit (000) is coupled to the antenna load (100) and is used to transmit signals with the antenna load (100).

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