Radio frequency front-end module

Abstract

The utility model provides a radio frequency front-end module, which comprises an antenna switch unit, a controller and at least one coupler, the antenna switch unit comprises a plurality of switch branches, each coupler comprises an isolation end and an adjustable matching network, and the controller is connected with each switch branch and each adjustable matching network. And the controller can control the on or off of each switch branch according to the frequency band of the radio frequency signal received by the antenna switch unit, and adjust the impedance value of the adjustable matching network. The coupler in the radio frequency front-end module has a good isolation effect on radio frequency signals of different frequency bands, so that the working performance of the radio frequency front-end module can be improved.

Description

Technical Field

[0001] The present application relates to the field of radio frequency technology, and in particular to a radio frequency front-end module. Background Art

[0002] The RF front-end module is one of the basic components used to realize wireless network communication. The coupler is a directional power coupling element. In the RF front-end module, the coupler is often used to couple out the RF signal with a certain coupling degree so as to observe or test it separately.

[0003] However, when the coupler in the current RF front-end module is working, it only has a good isolation effect on signals in a specific frequency band, and will absorb signals in other frequency bands, resulting in poor signal directionality of the coupler, thereby affecting the working performance of the RF front-end module. Utility Model Content

[0004] The main purpose of this application is to provide a radio frequency front-end module, aiming to solve the problem that the signal directivity of the coupler is poor, thereby affecting the working performance of the radio frequency front-end module.

[0005] In a first aspect, the present application provides a radio frequency front-end module, comprising:

[0006] The antenna switch unit comprises a plurality of switch branches; each of the switch branches is used to transmit a radio frequency signal of a set frequency band;

[0007] At least one coupler, the coupler comprising an input end, a first output end, a second output end, an isolation end and an adjustable matching network; the input end is connected to at least one of the switch branches, the input end and the first output end are connected via a first coupling line to transmit a first radio frequency signal; the second output end and the isolation end are connected via a second coupling line; the second coupling line is coupled to the first coupling line to generate a second radio frequency signal, the second output end is used to output the second radio frequency signal, and the adjustable matching network is provided between the isolation end and the ground end to provide an adjustable impedance;

[0008] A controller is connected to each of the switch branches and each of the adjustable matching networks; the controller is used to control each of the switch branches to be turned on or off and adjust the impedance value of the adjustable matching network according to the frequency band of the radio frequency signal received by the antenna switch unit.

[0009] In one embodiment, the plurality of switch branches include a plurality of first switch branches, and the at least one coupler includes a first coupler;

[0010] Each of the first switch branches is connected to the input end of the first coupler; the controller is connected to each of the first switch branches and the adjustable matching network of the first coupler;

[0011] The controller is used to control at least one of the first switch branches to be turned on according to a first frequency band of the radio frequency signal received by the antenna switch unit, and adjust the impedance value of the adjustable matching network to a first impedance value, wherein the first impedance value matches the first frequency band.

[0012] In one embodiment, the plurality of switch branches include at least one second switch branch and a plurality of third switch branches, and the at least one coupler includes a second coupler and a third coupler;

[0013] Each of the second switch branches is connected to the input end of the second coupler, and each of the third switch branches is connected to the input end of the third coupler; the controller is connected to each of the second switch branches and each of the third switch branches, and the controller is also connected to the adjustable matching network of the second coupler and the third coupler;

[0014] The controller is used to control at least one of the second switch branches and / or at least one of the third switch branches to be turned on according to the second frequency band of the radio frequency signal received by the antenna switch unit, and adjust the impedance value of at least one target adjustable matching network to a second impedance value, wherein the second impedance value matches the second frequency band, and the target adjustable matching network is connected to the turned-on second switch branch and / or the third switch branch.

[0015] In one embodiment, at least one of the second switch branches and at least one of the third switch branches are used to transmit radio frequency signals of a target set frequency band;

[0016] When the second frequency band includes the target set frequency band, the controller is further used to control at least one of the second switch branches and one of the at least one third switch branches to be turned on.

[0017] In one embodiment, the plurality of third switch branches include at least one fourth switch branch, and the second switch branch and the fourth switch branch are used to transmit radio frequency signals of different set frequency bands;

[0018] When the second frequency band includes two different set frequency bands, the controller is further used to control one of the second switch branches and one of the fourth switch branches to be turned on.

[0019] In one embodiment, the adjustable matching network includes a resistance unit and a capacitance unit connected in parallel;

[0020] The controller is connected to the resistor unit and the capacitor unit; the controller is also used to control the resistance value of the resistor unit and the capacitance value of the capacitor unit according to the frequency band of the radio frequency signal to adjust the impedance value of the adjustable matching network.

[0021] In one embodiment, the resistance unit includes a plurality of first branches connected in parallel, and the first branch includes a first switch and a first resistor connected in series;

[0022] The controller is connected to the control end of each first switch, and is further used to control each first switch to be turned on or off according to the frequency band of the radio frequency signal, so as to adjust the impedance value of the adjustable matching network.

[0023] In one embodiment, the capacitor unit includes a plurality of second branches connected in parallel, and the second branch includes a second switch and a first capacitor connected in series;

[0024] The controller is connected to the control end of each second switch, and is further used to control each second switch to be turned on or off according to the frequency band of the radio frequency signal, so as to adjust the impedance value of the adjustable matching network.

[0025] In one embodiment, the resistance unit includes a plurality of first branches connected in parallel, and the first branch includes a first switch and a first resistor connected in series;

[0026] The capacitor unit includes a plurality of second branches connected in parallel, wherein the second branch includes a second switch and a first capacitor connected in series;

[0027] The controller is connected to the control end of each of the first switches and the control end of each of the second switches; the controller is also used to control at least one of the first switches and / or at least one of the second switches to be turned on according to the frequency band of the radio frequency signal.

[0028] In one embodiment, the RF front-end module also includes a power amplifier, which is connected to the antenna switch unit; the power amplifier is used to amplify the power of the RF signal and input the power-amplified RF signal to the antenna switch unit.

[0029] The RF front-end module provided in the embodiment of the present application includes an antenna switch unit, a controller and at least one coupler. Among them, the antenna switch unit includes a plurality of switch branches, the coupler includes an isolation end and an adjustable matching network, and the controller is connected to each switch branch and each adjustable matching network. The controller can control each switch branch to be turned on or off according to the frequency band of the RF signal received by the antenna switch unit, and adjust the impedance value of the adjustable matching network. The controller in the RF front-end module can perform linkage control on the plurality of switch branches in the antenna switch unit and the adjustable matching network in at least one coupler, and can adjust the impedance value of the adjustable matching network while selecting the switch branch, so as to improve the isolation effect of the isolation end on RF signals of different frequency bands, thereby improving the directivity of the coupler, and further improving the working performance of the RF front-end module. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0031] Figure 1 A circuit diagram of an implementation of a radio frequency front-end module provided in an embodiment of the present application;

[0032] Figure 2 A circuit diagram of another implementation of the RF front-end module provided in an embodiment of the present application;

[0033] Figure 3 A circuit diagram of another implementation of the RF front-end module provided in an embodiment of the present application;

[0034] Figure 4 A circuit diagram of another implementation of the RF front-end module provided in an embodiment of the present application;

[0035] Figure 5 A circuit diagram of another implementation of the RF front-end module provided in an embodiment of the present application;

[0036] Figure 6 A circuit diagram of another implementation of the RF front-end module provided in an embodiment of the present application;

[0037] Figure 7 A circuit diagram of another implementation of the RF front-end module provided in an embodiment of the present application;

[0038] Figure 8 A circuit diagram of an implementation of a coupler provided in an embodiment of the present application;

[0039] Fig. 9 A circuit diagram of another implementation of the coupler provided in an embodiment of the present application;

[0040] Fig.10 A circuit diagram of another implementation of the RF front-end module provided in an embodiment of the present application.

[0041] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0042] It should be noted that the terms "first" and "second" in the specification, claims and drawings of the present application are used to distinguish similar objects rather than to describe a specific order or sequence.

[0043] It should also be noted that the method disclosed in the embodiments of the present application or the method shown in the flowchart includes one or more steps for implementing the method. Without departing from the scope of the claims, the execution order of multiple steps can be interchangeable with each other, and some of the steps can also be deleted.

[0044] This embodiment provides a radio frequency front-end module, which is a component that integrates two or more discrete devices such as a radio frequency switch, a low noise amplifier, a filter, a duplexer, a power amplifier, and a transformer into an independent module, thereby improving the integration and hardware performance of the radio frequency front-end module and miniaturizing its size. Specifically, the radio frequency front-end module can be applied to 4G and 5G communication devices such as smart phones, tablet computers, and smart watches.

[0045] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0046] Please refer to Figure 1 and Figure 2 , Figure 1 and Figure 2 A circuit diagram of an implementation of a radio frequency front-end module provided in an implementation of the present application.

[0047] like Figure 1As shown, the RF front-end module 100 includes an antenna switch unit 110, a controller 130 and at least one coupler 120. The antenna switch unit 110 is used to transmit RF signals of multiple frequency bands, which include two or more frequency bands, and the multiple frequency bands may include a low frequency band, a medium frequency band and a high frequency band. For example, the antenna switch unit 110 can transmit RF signals of the B1 frequency band and RF signals of the B5 frequency band. The coupler 120 is connected to the antenna switch unit 110, and the coupler 120 is used to couple the first RF signal with a certain coupling degree to generate a second RF signal, for example, the first RF signal Rf1 is coupled to obtain the second RF signal Rf2. The controller 130 is connected to the antenna switch unit 110 and the coupler 120, and is used to control the antenna switch unit 110 and the coupler 120. It should be noted that, Figure 1 This is an example in which the RF front-end module 100 includes one coupler. In actual applications, the RF front-end module 100 may also include two, three or more couplers.

[0048] like Figure 2 As shown, the antenna switch unit 110 includes a plurality of switch branches 111, each switch branch 111 is used to transmit a radio frequency signal of a set frequency band, such as a first radio frequency signal Rf1. Each switch branch 111 may correspond to a set frequency band, and the set frequency bands corresponding to different switch branches 111 may be the same or different. The set frequency band corresponding to each switch branch 111 may be pre-set, and the set frequency band may be a low frequency band, a medium frequency band, or a high frequency band. For example, the set frequency band may include frequency bands such as B1, B3, B5, B8, B40, and B41.

[0049] The coupler 120 includes an input terminal Va, a first output terminal Vb, a second output terminal Vc, an isolation terminal Vd, and an adjustable matching network 121. The input terminal Va is connected to at least one switch branch 111, and the input terminal Va is connected to the first output terminal Vb through a first coupling line to transmit a first radio frequency signal Rf1. The second output terminal Vc is connected to the isolation terminal Vd through a second coupling line. The second coupling line is coupled to the first coupling line to generate a second radio frequency signal Rf2, and the second output terminal Vc is used to output the second radio frequency signal Rf2. The adjustable matching network 121 is arranged between the isolation terminal Vd and the ground terminal to provide an adjustable impedance.

[0050] It should be noted that the first RF signal Rf1 can be output through the first output terminal Vb. For example, the first output terminal Vb can be connected to the antenna port so as to transmit the first RF signal Rf1 to the antenna for transmission. When the first RF signal Rf1 is transmitted on the first coupling line, a small portion of the power will be coupled to the second coupling line to obtain the second RF signal Rf2. The second RF signal Rf2 can be output through the second output terminal Vc. The second output terminal Vc can be used to connect to an external circuit (such as a power detection circuit) so that the external circuit can calculate the power parameters and other information of the first RF signal Rf1 by detecting the power of the second RF signal Rf2. The adjustable matching network 121 can provide adjustable impedance. When the antenna switch unit 110 receives RF signals of different frequency bands, the isolation of the isolation terminal Vd can be changed by adjusting the impedance value of the adjustable matching network 121, thereby improving the isolation effect of RF signals of different frequency bands.

[0051] The controller 130 is connected to each switch branch 111 (not shown in the figure), and is also connected to the adjustable matching network 121 in each coupler 120. The controller 130 is used to control each switch branch 111 to be turned on or off according to the frequency band of the RF signal received by the antenna switch unit 110, and to adjust the impedance value of the adjustable matching network 121.

[0052] Among them, the frequency band of the RF signal can be one or more. For example, when multiple RF signals are transmitted to the antenna switch unit 110, the frequency bands of the multiple RF signals can be different. It should be noted that since each switch branch 111 corresponds to a set frequency band, when the RF signal passes through the antenna switch unit 110, it is necessary to control the switch branch 111 that matches the frequency band of the RF signal to be turned on, and control the other switch branches 111 to be disconnected, so that the RF signal, such as the first RF signal Rf1, can be transmitted to the coupler 120 without interference, thereby reducing the transmission loss of the first RF signal Rf1.

[0053] Since the adjustable matching network 121 in the coupler 120 is at different impedance values, the isolation effect of the isolation terminal Vd on the RF signal is different. Therefore, in the embodiment of the present application, when the RF signal passes through the coupler 120, the impedance value of the adjustable matching network 121 is adjusted so that the impedance value of the adjustable matching network 121 matches the RF signal, such as the first RF signal Rf1, thereby improving the isolation of the isolation terminal Vd, and further improving the isolation effect on the first RF signal Rf1.

[0054] It is understandable that, ideally, there is no signal output at the isolation terminal Vd. However, in actual situations, the isolation of the coupler 120 is not infinite, and there will be signal leakage at the isolation terminal Vd. Moreover, the isolation of the coupler 120 is related to the frequency of the RF signal and the impedance of the isolation terminal Vd. Therefore, by providing an adjustable impedance by setting an adjustable matching network 121, the isolation of RF signals of different frequency bands can be improved, and not only the RF signals of a specific frequency band have a better isolation effect. Therefore, the embodiment of the present application can improve the isolation effect of RF signals of multiple different frequency bands.

[0055] In the embodiment of the present application, an antenna switch unit 110 including a plurality of switch branches 111 and an adjustable matching network 121 providing adjustable impedance are provided, and the plurality of switch branches 111 and the adjustable matching network 121 are controlled in linkage through a controller 130. When the switch branch 111 is selected, the impedance value of the adjustable matching network 121 can be adjusted, so that the isolation degree of the isolation terminal Vd of the coupler 120 to the RF signals of different frequency bands can be improved, thereby improving the isolation effect of the coupler 120 to the RF signals of different frequency bands, and thus improving the directivity of the coupler 120, thereby improving the working performance of the RF front-end module 100.

[0056] For example, Figure 3 As shown, the multiple switch branches include multiple first switch branches, such as the first switch branch 1101 to the first switch branch 1104, and at least one coupler includes a first coupler 1201. Each first switch branch is connected to the input terminal Va of the first coupler 1201. The controller 130 is connected to each first switch branch (not shown in the figure), and the controller 130 is also connected to the adjustable matching network 121 of the first coupler 1201. The controller 130 is used to control at least one first switch branch to be turned on according to the first frequency band of the radio frequency signal received by the antenna switch unit, and adjust the impedance value of the adjustable matching network 121 to a first impedance value, wherein the first impedance value matches the first frequency band.

[0057] It should be noted that, in the scenario where the RF front-end module 100 includes a first coupler 1201 and multiple first switch branches, each first switch branch is connected to the input end of the first coupler 1201. When the antenna switch unit receives the first RF signal Rf1 of the first frequency band, the controller 130 can determine the first switch branch that matches the first frequency band, and the first impedance value that matches the first frequency band. As an implementation method, the matching method of the first impedance value and the first frequency band can be implemented through a mapping relationship table, for example, the mapping relationship table stores the matching relationship between multiple frequency bands and multiple impedance values, and the first impedance value that matches the first frequency band can be determined by querying the mapping relationship table. As another implementation method, the matching method of the first impedance value and the first frequency band can be implemented by the timing control of the controller. For example, within a specific time segment, the first switch branch receives the RF signal of the first frequency band, and within the specific time segment, the controller adjusts the impedance value of the adjustable matching network to the first impedance value, thereby achieving the matching of the first impedance value and the first frequency band. In this scenario, multiple first switch branches cannot be turned on at the same time, that is, at most only one first switch branch can be turned on at the same time, for example, a corresponding first switch branch can be controlled to be turned on according to the transmission time of the RF signal. Therefore, the controller 130 can control the first switch branch to be turned on according to the first frequency band, and adjust the impedance value of the adjustable matching network 121 to the first impedance value.

[0058] For example, the low frequency bands in the 4G communication field may include B5, B8, B20, B28, etc. If the first switch branch 1101 is used to transmit a radio frequency signal with a set frequency band of B5, the impedance value corresponding to B5 is Z1. The first switch branch 1102 is used to transmit a radio frequency signal with a set frequency band of B8, and the impedance value corresponding to B8 is Z2. The first switch branch 1103 is used to transmit a radio frequency signal with a set frequency band of B20, and the impedance value corresponding to B20 is Z3. The first switch branch 1104 is used to transmit a radio frequency signal with a set frequency band of B28, and the impedance value corresponding to B28 is Z4. When the first frequency band of the radio frequency signal received by the antenna switch unit is B8, the controller 130 can control the first switch branch 1102 to be turned on, and adjust the impedance value of the adjustable matching network 121 to Z2. When the first frequency band of the radio frequency signal received by the antenna switch unit is B28, the controller 130 can control the first switch branch 1104 to be turned on, and adjust the impedance value of the adjustable matching network 121 to Z4.

[0059] For another example, the low frequency bands in the 5G communication field may include N5, N8, N20, N28, etc. If the first switch branch 1101 is used to transmit the RF signal with the set frequency band N5, the impedance value corresponding to N5 is Z11. The first switch branch 1102 is used to transmit the RF signal with the set frequency band N8, and the impedance value corresponding to N8 is Z12. The first switch branch 1103 is used to transmit the RF signal with the set frequency band N20, and the impedance value corresponding to N20 is Z13. The first switch branch 1104 is used to transmit the RF signal with the set frequency band N28, and the impedance value corresponding to N28 is Z14. When the first frequency band of the RF signal received by the antenna switch unit includes N5 and N8, the controller 130 can control the first switch branch 1101 to be turned on when transmitting the RF signal with the first frequency band N5, and the other first switch branches to be turned off, and adjust the impedance value of the adjustable matching network 121 to Z11. The controller 130 can control the first switch branch 1102 to be turned on, control the first switch branch 1101 to be turned off, and adjust the impedance value of the adjustable matching network 121 to Z12 when transmitting the RF signal with the first frequency band N8.

[0060] For example, Figure 4 As shown, the plurality of switch branches include at least one second switch branch and a plurality of third switch branches, at least one second switch branch such as the second switch branch 1106, and a plurality of third switch branches such as the third switch branch 1107 to the third switch branch 1110. At least one coupler includes a second coupler 1202 and a third coupler 1203. Each second switch branch is connected to the input end of the second coupler 1202, and each third switch branch is connected to the input end of the third coupler 1203. The controller 130 is connected to each second switch branch and each third switch branch (not shown in the figure), and the controller 130 is also connected to the adjustable matching network in the second coupler 1202 and the third coupler 1203.

[0061] The controller 130 is used to control at least one second switch branch and / or at least one third switch branch to be turned on according to the second frequency band of the radio frequency signal received by the antenna switch unit, and adjust the impedance value of at least one target adjustable matching network to a second impedance value, wherein the second impedance value matches the second frequency band, and the target adjustable matching network is connected to the turned-on second switch branch and / or third switch branch.

[0062] It should be noted that in some application scenarios of the RF front-end module 100, multiple couplers are required to monitor power, such as application scenarios where low-frequency LB signals and intermediate-frequency MB signals need to be transmitted simultaneously, or application scenarios where intermediate-frequency MB signals and high-frequency HB signals need to be transmitted simultaneously, or application scenarios where low-frequency LB signals and high-frequency HB signals need to be transmitted simultaneously. In these application scenarios, multiple switch branches that are turned on can be connected to different couplers to facilitate power detection of multiple RF signals to be transmitted. By setting at least one second switch branch and multiple third switch branches, and connecting the second switch branch and the third switch branch to the second coupler 1202 and the third coupler 1203, respectively, different RF signals can be transmitted to the corresponding couplers respectively, and the isolation effect of each coupler on RF signals of different frequency bands is guaranteed, thereby improving the working performance of the RF front-end module 100.

[0063] It should be noted that the RF front-end module 100 may be provided with a second coupler 1202 and a third coupler 1203, the second switch branch 1106 is connected to the input end of the second coupler 1202, and each third switch branch 1107 to the third switch branch 1110 is connected to the input end of the third coupler 1203. When the antenna switch unit receives a radio frequency signal of the second frequency band, the controller 130 may turn on at least one of the second switch branch 1106 and / or the third switch branch 1107 to the third switch branch 1110 that matches the second frequency band, and determine a second impedance value that matches the second frequency band. Among them, the antenna switch unit may simultaneously receive one or more radio frequency signals of the second frequency band, and when receiving radio frequency signals of multiple second frequency bands at the same time, the multiple second frequency bands may be different frequency bands. For example, the second frequency band is a mid-frequency band, including but not limited to frequency bands such as B1, B3, B40, and B41. The radio frequency signal received by the antenna switch unit may be one or more of the frequency bands such as B1, B3, B40, and B41.

[0064] That is, when there is one second frequency band, the controller 130 can control a second switch branch or a third switch branch to be turned on according to the second frequency band, and adjust the impedance value of the adjustable matching network in the coupler connected to the turned-on switch branch to the corresponding second impedance value. Alternatively, the controller 130 can control a second switch branch and a third switch branch to be turned on, and respectively adjust the impedance value of the adjustable matching network connected to the turned-on second switch branch and the third switch branch to the corresponding second impedance value. Correspondingly, when there are multiple second frequency bands, the second impedance value can also be multiple, respectively adapted to the second coupler 1202 and / or the third coupler 1203.

[0065] For example, the second switch branch 1106 is used to transmit a radio frequency signal with a set frequency band of B8, and the impedance value corresponding to B8 is Z6. The third switch branch 1107 is used to transmit a radio frequency signal with a set frequency band of B41, and the impedance value corresponding to B41 is Z7. The third switch branch 1108 is used to transmit a radio frequency signal with a set frequency band of B40, and the impedance value corresponding to B40 is Z8. The third switch branch 1109 is used to transmit a radio frequency signal with a set frequency band of B3, and the impedance value corresponding to B3 is Z9. The third switch branch 1110 is used to transmit a radio frequency signal with a set frequency band of B1, and the impedance value corresponding to B1 is Z10. If the second frequency band of the radio frequency signal received by the antenna switch unit is B3, the controller 130 can control the third switch branch 1109 to be turned on, and adjust the impedance value of the adjustable matching network in the third coupler 1203 to Z9. If the second frequency band of the RF signal received by the antenna switch unit 110 is B3 and B8, the controller 130 can control the second switch branch 1106 and the third switch branch 1109 to be turned on, and adjust the impedance value of the adjustable matching network in the second coupler 1202 to Z6, and adjust the impedance value of the adjustable matching network in the third coupler 1203 to Z9.

[0066] It is understandable that the number of the second switch branches may be two or more. Figure 5 As shown, the second switch branch includes a second switch branch 1106A and a second switch branch 1106B, and a plurality of third switch branches such as a third switch branch 1107 to a third switch branch 1110. Among them, the second switch branch 1106A is used to transmit a radio frequency signal with a set frequency band of B41, and the impedance value corresponding to B41 is Z6. The second switch branch 1106B is used to transmit a radio frequency signal with a set frequency band of B66, and the impedance value corresponding to B66 is Z6. The third switch branch 1107 is used to transmit a radio frequency signal with a set frequency band of B41, and the impedance value corresponding to B41 is Z6. The third switch branch 1108 is used to transmit a radio frequency signal with a set frequency band of B40, and the impedance value corresponding to B40 is Z8. The third switch branch 1109 is used to transmit a radio frequency signal with a set frequency band of B3, and the impedance value corresponding to B3 is Z9. The third switch branch 1110 is used to transmit a radio frequency signal with a set frequency band of B1, and the impedance value corresponding to B1 is Z10. If the second frequency band of the RF signal received by the antenna switch unit is B3, the controller 130 can control the third switch branch 1109 to be turned on, and adjust the impedance value of the adjustable matching network in the third coupler 1203 to Z9. If the second frequency band of the RF signal received by the antenna switch unit 110 is B3 and B41, the controller 130 can control the third switch branch 1109 to be turned on, control the second switch branch 1106A to be turned on, and adjust the impedance value of the adjustable matching network in the second coupler 1202 to Z6, and adjust the impedance value of the adjustable matching network in the third coupler 1203 to Z9.

[0067] In one embodiment, at least one second switch branch and at least one third switch branch are both used to transmit radio frequency signals of a target set frequency band. When the second frequency band includes the target set frequency band, the controller is further used to control one of the at least one second switch branch and the at least one third switch branch to be turned on.

[0068] Among them, at least one second switch branch and at least one third switch branch are used to receive radio frequency signals of the same set frequency band, and the same set frequency band is, for example, a target set frequency band, and the target set frequency band is, for example, B41. It should be noted that at least one second switch branch and at least one third switch branch for receiving radio frequency signals of the same set frequency band cannot be turned on at the same time. Therefore, when the second frequency band includes the target set frequency band, the controller can control at least one second switch branch and one of the at least one third switch branches to be turned on, thereby avoiding the radio frequency signal of the target set frequency band from being shunted to different couplers, thereby improving the reliability of the coupler.

[0069] For example, Figure 6 As shown, the second switch branch 1106 is connected to the input end of the second coupler 1202, and each of the third switch branches 1107 to the third switch branch 1110 is connected to the input end of the third coupler 1203. Among them, the second switch branch 1106 is used to transmit the RF signal with a set frequency band of B41, and the third switch branch 1107 is also used to transmit the RF signal with a set frequency band of B41. When the second frequency band of the RF signal includes B41, the controller 130 can control one of the second switch branch 1106 and the third switch branch 1107 to be turned on.

[0070] In one embodiment, the plurality of third switch branches include at least one fourth switch branch, and the second switch branch and the fourth switch branch are used to transmit radio frequency signals of different set frequency bands. When the second frequency band includes two different set frequency bands, the controller is further used to control a second switch branch and a fourth switch branch to be turned on.

[0071] It should be noted that the plurality of third switch branches include at least one fourth switch branch, and the fourth switch branch and the second switch branch are used to receive radio frequency signals of different set frequency bands. At most, only one second switch branch or one fourth switch branch can be turned on at the same time. Therefore, when the second frequency band includes two different set frequency bands, a second switch branch and a fourth switch branch can be turned on by a controller, thereby ensuring that at least two radio frequency signals of the second frequency band can pass through the second switch branch and a fourth switch branch through the antenna switch unit respectively.

[0072] For example, Figure 6As shown, the second switch branch 1106 is connected to the input end of the second coupler 1202, and each of the third switch branches 1107 to the third switch branch 1110 is connected to the input end of the third coupler 1203. Among them, the second switch branch 1106 and the third switch branch 1107 are used to transmit RF signals with a set frequency band of B41, and the third switch branch 1108 to the third switch branch 1110 are used to transmit RF signals of other set frequency bands (including the middle frequency bands B1, B3, and B40). Therefore, Figure 6 The third switch branch 1108 to the third switch branch 1110 shown can all be used as the fourth switch branch. When the second frequency band includes set frequency bands such as B41 and B3, the controller 130 can control the second switch branch 1106 to be turned on, and the controller 130 can also control the third switch branch 1109 as the fourth switch branch to be turned on.

[0073] In one embodiment, if Figure 7 As shown, the multiple switch branches include multiple first switch branches (such as the first switch branch 1101 to the first switch branch 1104), at least one second switch branch (such as the second switch branch 1106A and the second switch branch 1106B) and multiple third switch branches (such as the third switch branch 1108 to the third switch branch 1110). At least one coupler includes a first coupler 1201, a second coupler 1202 and a third coupler 1203. Each first switch branch is connected to the input end of the first coupler 1201, each second switch branch is connected to the input end of the second coupler 1202, and each third switch branch is connected to the input end of the third coupler 1203. The controller 130 is connected to each first switch branch, each second switch branch, and each third switch branch (not shown in the figure), and the controller 130 is also connected to the adjustable matching network 121 of the first coupler 1201, the second coupler 1202, and the third coupler 1203. The controller 130 is used to control at least one first switch branch to be turned on according to the first frequency band of the radio frequency signal received by the antenna switch unit, and adjust the impedance value of the adjustable matching network 121 to the first impedance value.

[0074] Among them, the first switch branch 1101 to the first switch branch 1104 can be used to transmit low-frequency RF signals, such as RF signal Rf11, and the low-frequency band includes B5, B8, B20 and B28. The second switch branch 1106A and the second switch branch 1106B can be used to transmit high-frequency RF signals, such as RF signal Rf13, and the high-frequency band includes B41 and B66. The third switch branch 1108 to the third switch branch 1110 can be used to transmit medium-frequency RF signals, such as RF signal Rf12, and the medium-frequency band includes B1, B3 and B40. When the antenna switch unit receives a RF signal, the controller 130 can control a first switch branch, a second switch branch and / or a third switch branch to be turned on according to the signal frequency band of the RF signal, and adjust the impedance value of the adjustable matching network in the coupler connected to the turned-on switch branch to the corresponding impedance value.

[0075] The above example specifically explains the connection relationship between the antenna switch unit 110, at least one coupler 120 and the controller 130 in the RF front-end module 100. The specific structure of the switch branch in the antenna switch unit 110 and the adjustable matching network in the coupler 120 is exemplified below.

[0076] In one embodiment, the switch branch includes a switch unit, which is used to control the switch branch to be turned on or off. The controller is connected to the switch unit, and is used to control the switch unit to be turned on or off, so as to control each switch branch to be turned on or off.

[0077] It should be noted that the on or off of each switch branch can be controlled by a switch unit. For example, the switch branch is in an on state when the internal switch unit is on, and the switch branch is in an off state when the internal switch unit is off. The switch unit can be integrated into the chip, usually implemented by a transistor. In some examples, the switch unit can also be integrated into the substrate, and the switch unit includes, for example, a switch tube such as a triode and a MOS tube.

[0078] In one embodiment, if Figure 1 and Figure 8 As shown, the adjustable matching network includes a resistor unit 1211 and a capacitor unit 1212 connected in parallel. The controller 130 is connected to the resistor unit 1211 and the capacitor unit 1212. The controller 130 is also used to control the resistance value of the resistor unit 1211 and the capacitance value of the capacitor unit 1212 according to the frequency band of the radio frequency signal to adjust the impedance value of the adjustable matching network 121.

[0079] It should be noted that the frequency band of the RF signal may be the frequency band of the RF signal received by the antenna switch unit 110. By setting the resistor unit 1211 and the capacitor unit 1212 connected in parallel, the controller 130 can control the resistance value of the resistor unit 1211 and the capacitance value of the capacitor unit 1212, so as to adjust the impedance value of the adjustable matching network 121, so as to adaptively improve the isolation effect of the isolation end on RF signals of different frequency bands, thereby improving the directivity of the coupler 120.

[0080] For example, Fig. 9 As shown, the resistance unit 1211 includes a plurality of first branches connected in parallel, and the first branch includes a first switch K1 and a first resistor R1 connected in series. The controller 130 is connected to the control end of each first switch K1, and the controller 130 is also used to control each first switch K1 to be turned on or off according to the frequency band of the radio frequency signal to adjust the impedance value of the adjustable matching network.

[0081] It should be noted that the first resistor R1 in each first branch may be one or more. The resistance value of the first resistor R1 in each first branch may be the same or different. The connection position of the first switch K1 and the first resistor R1 may be interchangeable, or other devices may be added as required. When the resistance unit 1211 includes multiple first branches in parallel, the controller 130 can adjust the resistance value of the resistance unit 1211 by controlling the conduction or disconnection of the first switch K1 in each first branch, thereby achieving the impedance value adjustment of the adjustable matching network, and the resistance adjustment has high reliability and more adjustment levels.

[0082] For example, Fig. 9 As shown, the capacitor unit 1212 includes a plurality of second branches connected in parallel, and the second branch includes a second switch K2 and a first capacitor C1 connected in series; the controller 130 is connected to the control end of each second switch K2, and the controller 130 is also used to control each second switch K2 to be turned on or off according to the frequency band of the radio frequency signal to adjust the impedance value of the adjustable matching network.

[0083] It should be noted that the first capacitor C1 in each second branch can be one or more. The capacitance value of the first capacitor C1 in each second branch can be the same or different. The connection position of the second switch K2 and the first capacitor C1 can be interchanged, or other devices can be added as required. When the capacitor unit 1212 includes multiple second branches in parallel, the controller 130 can adjust the capacitance value of the capacitor unit 1212 by controlling the conduction or disconnection of the second switch K2 in each second branch, so that the impedance value of the adjustable matching network 121 can be adjusted, and the reliability of the capacitor adjustment is high and the capacitor adjustment level is more.

[0084] For example, Fig. 9 As shown, the resistance unit 1211 includes a plurality of first branches connected in parallel, and the first branch includes a first switch K1 and a first resistor connected in series; the capacitance unit 1212 includes a plurality of second branches connected in parallel, and the second branch includes a second switch K2 and a first capacitor C1 connected in series; the controller 130 is connected to the control end of each first switch K1 and the control end of each second switch K2; the controller 130 is also used to control at least one first switch K1 and / or at least one second switch K2 to be turned on according to the frequency band of the radio frequency signal.

[0085] It should be noted that the controller 130 can control at least one first switch K1 in the resistor unit 1211 to be turned on, and all the second switches K2 to be turned off, and at this time the adjustable matching network is purely resistive. The controller 130 can also control at least one second switch K2 in the capacitor unit 1212 to be turned on, and all the first switches K1 to be turned off, and at this time the adjustable matching network is purely capacitive. The controller 130 can also control at least one first switch K1 and at least one second switch K2 to be turned on according to the frequency band of the RF signal, so as to adjust the impedance value of the adjustable matching network, so that the adjusted impedance value matches the frequency band of the RF signal, thereby improving the isolation effect of the isolation end on RF signals of different frequency bands, and thus improving the directivity of the coupler 120. The adjustable matching network provided in the embodiment of the present application can provide multiple gears of impedance values. If the resistor unit 1211 and the capacitor unit 1212 each have n branches, a total of 2 can be achieved. n The impedance adjustment has high reliability and low cost.

[0086] In one example, the manner of controlling at least one first switch and / or at least one second switch to be turned on according to the frequency band of the radio frequency signal to adjust the impedance value of the adjustable matching network can refer to the following table:

[0087] Frequency band Resistance Value Capacitance B8 50 0.2pF B5 44 0.2pF B41 20 1.5pF …… …… ……

[0088] In some examples, the resistance unit 1211 may include an adjustable resistance element. The controller 130 is connected to the control end of the adjustable resistance element, and the controller 130 is also used to control the resistance value of the adjustable resistance element according to the frequency band of the radio frequency signal received by the antenna switch unit 110 to adjust the impedance value of the adjustable matching network.

[0089] In some examples, the capacitor unit 1212 includes an adjustable capacitor element. The controller 130 is connected to the control end of the adjustable capacitor element, and the controller 130 is also used to control the capacitance value of the adjustable capacitor element according to the frequency band of the radio frequency signal received by the antenna switch unit 110 to adjust the impedance value of the adjustable matching network.

[0090] In some examples, the adjustable matching network may further include an inductor unit, which may include an adjustable inductor element, or the inductor unit may include a plurality of third branches connected in parallel, the third branch including a third switch and a first inductor connected in series. The controller 130 may adjust the impedance value of the adjustable matching network by controlling the inductance value of the inductor unit.

[0091] In one embodiment, if Fig.10 As shown, the RF front-end module 100 further includes a power amplifier 140, which is connected to the antenna switch unit 110. The power amplifier 140 is used to amplify the power of the RF signal and input the amplified RF signal to the antenna switch unit 110.

[0092] For example, the power amplifier 140 amplifies the power of the RF signal and inputs the power-amplified RF signal as the first RF signal Rf1 to the antenna switch unit 110. The controller 130 controls the target switch branch in the antenna switch unit 110 to be turned on according to the first frequency band of the first RF signal Rf1 received by the antenna switch unit 110, and adjusts the impedance value of the adjustable matching network in the coupler 120 to the target impedance value. The set frequency band corresponding to the target switch branch matches the first frequency band, and the target impedance value also matches the first frequency band.

[0093] As an implementation, the RF front-end module 100 may include one or more power amplifiers 140. The number of power amplifiers 140 may be the same as the number of couplers 120, and each power amplifier 140 corresponds to one coupler 120, and each power amplifier 140 is connected to the corresponding coupler through an antenna switch unit 110. Exemplarily, the RF front-end module 100 includes a first power amplifier, a second power amplifier, and a third power amplifier, wherein the first power amplifier is connected to the first coupler through the first antenna switch unit; the second power amplifier is connected to the second coupler through the second antenna switch unit; and the third power amplifier is connected to the third coupler through the third antenna switch unit.

[0094] It should be noted that the power amplifier 140 may include one or more power amplifier modules, each of which is used to amplify the RF signal of a set frequency band. For example, the first power amplifier may include a broadband power amplifier module, which can amplify the RF signals of multiple low frequency bands such as B5, B8, B20, and B28. For another example, the first power amplifier may include one or more power amplifier modules, each of which is used to amplify one of the RF signals of low frequency bands such as B5, B8, B20, and B28.

[0095] The RF front-end module 100 of the above-mentioned embodiment can perform linkage control on multiple switch branches 111 in the antenna switch unit 110 and an adjustable matching network 121 in at least one coupler 120 through the controller 130, and can also adjust the impedance value of the adjustable matching network 121 while selecting the switch branch 111, thereby improving the isolation effect of the isolation end on RF signals of different frequency bands, thereby improving the directivity of the coupler 120, and further improving the working performance of the RF front-end module 100.

[0096] The disclosure above provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described above. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the various specific processes and material examples provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0097] The embodiments of the present application are described in detail above in conjunction with the accompanying drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present application.

Claims

1. A radio frequency front-end module, characterized in that: include: An antenna switch unit, comprising a plurality of switch branches; Each of the switch branches is used to transmit a radio frequency signal of a set frequency band; At least one coupler, the coupler comprising an input end, a first output end, a second output end, an isolation end, and an adjustable matching network; the input end is connected to at least one of the switch branches, and the input end is connected to the first output end through a first coupling line to transmit a first radio frequency signal; The second output terminal is connected to the isolation terminal via a second coupling line; The second coupling line is coupled to the first coupling line to generate a second radio frequency signal, the second output terminal is used to output the second radio frequency signal, and the adjustable matching network is provided between the isolation terminal and the ground terminal to provide an adjustable impedance; A controller is connected to each of the switch branches and each of the adjustable matching networks; the controller is used to control each of the switch branches to be turned on or off and adjust the impedance value of the adjustable matching network according to the frequency band of the radio frequency signal received by the antenna switch unit.

2. The RF front-end module according to claim 1, characterized in that: The plurality of switch branches include a plurality of first switch branches, and the at least one coupler includes a first coupler; Each of the first switch branches is connected to the input end of the first coupler; the controller is connected to each of the first switch branches and the adjustable matching network of the first coupler; The controller is used to control at least one of the first switch branches to be turned on according to a first frequency band of the radio frequency signal received by the antenna switch unit, and adjust the impedance value of the adjustable matching network to a first impedance value, wherein the first impedance value matches the first frequency band.

3. The RF front-end module according to claim 1, characterized in that: The plurality of switch branches include at least one second switch branch and a plurality of third switch branches, and the at least one coupler includes a second coupler and a third coupler; Each of the second switch branches is connected to the input end of the second coupler, and each of the third switch branches is connected to the input end of the third coupler; the controller is connected to each of the second switch branches and each of the third switch branches, and the controller is also connected to the adjustable matching network of the second coupler and the third coupler; The controller is used to control at least one of the second switch branches and / or at least one of the third switch branches to be turned on according to the second frequency band of the radio frequency signal received by the antenna switch unit, and adjust the impedance value of at least one target adjustable matching network to a second impedance value, wherein the second impedance value matches the second frequency band, and the target adjustable matching network is connected to the turned-on second switch branch and / or the third switch branch.

4. The RF front-end module according to claim 3, characterized in that: At least one of the second switch branches and at least one of the third switch branches are used to transmit a radio frequency signal of a target set frequency band; When the second frequency band includes the target set frequency band, the controller is further used to control at least one of the second switch branches and one of the at least one third switch branches to be turned on.

5. The RF front-end module according to claim 3, characterized in that: The plurality of third switch branches include at least one fourth switch branch, and the second switch branch and the fourth switch branch are used to transmit radio frequency signals of different set frequency bands; When the second frequency band includes two different set frequency bands, the controller is further used to control one of the second switch branches and one of the fourth switch branches to be turned on.

6. The RF front-end module according to any one of claims 1 to 5, characterized in that: The adjustable matching network includes a resistance unit and a capacitance unit connected in parallel; The controller is connected to the resistor unit and the capacitor unit; the controller is also used to control the resistance value of the resistor unit and the capacitance value of the capacitor unit according to the frequency band of the radio frequency signal to adjust the impedance value of the adjustable matching network.

7. The RF front-end module according to claim 6, characterized in that: The resistance unit includes a plurality of first branches connected in parallel, wherein the first branch includes a first switch and a first resistor connected in series; The controller is connected to the control end of each first switch, and is further used to control each first switch to be turned on or off according to the frequency band of the radio frequency signal, so as to adjust the impedance value of the adjustable matching network.

8. The RF front-end module according to claim 6, characterized in that: The capacitor unit includes a plurality of second branches connected in parallel, wherein the second branch includes a second switch and a first capacitor connected in series; The controller is connected to the control end of each second switch, and is further used to control each second switch to be turned on or off according to the frequency band of the radio frequency signal, so as to adjust the impedance value of the adjustable matching network.

9. The RF front-end module according to claim 6, characterized in that: The resistance unit includes a plurality of first branches connected in parallel, wherein the first branch includes a first switch and a first resistor connected in series; The capacitor unit includes a plurality of second branches connected in parallel, wherein the second branch includes a second switch and a first capacitor connected in series; The controller is connected to the control end of each of the first switches and the control end of each of the second switches; the controller is also used to control at least one of the first switches and / or at least one of the second switches to be turned on according to the frequency band of the radio frequency signal.

10. The RF front-end module according to any one of claims 1 to 5, characterized in that: The RF front-end module also includes a power amplifier, which is connected to the antenna switch unit; the power amplifier is used to amplify the power of the RF signal and input the power-amplified RF signal to the antenna switch unit.

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