Radio frequency switch circuit, device and radio frequency equipment

Abstract

The application discloses a radio frequency switch circuit, a device and a radio frequency equipment. The radio frequency switch circuit comprises a passive structure device, the passive structure device comprises a plurality of switch access ports, and each switch access port of the passive structure device is connected with a corresponding switch module. The switch module is composed of at least one radio frequency switch and a function maintaining unit in parallel, one end of the radio frequency switch is connected with the switch access port, and the other end of the radio frequency switch is connected with a switch port. The function maintaining unit is used for maintaining the function of the passive device. The technical scheme can reduce the insertion loss of the single-pole multi-throw switch in the radio frequency circuit.

Description

Technical Field

[0001] This application relates to the field of switching circuit technology, and in particular to a radio frequency switching circuit, device, and radio frequency equipment. Background Technology

[0002] In radio frequency (RF) circuits, single-pole multiple-throw (SPMD) switches are commonly used for circuit multiplexing to reduce costs. RF circuits also frequently employ passive structural modules such as baluns, couplers, and 3dB bridges for signal synthesis and distribution. However, when one of the switches in a SPMD switch is closed to form a circuit, parasitic capacitance exists between the input and output terminals of each open switch. These parasitic capacitances increase the insertion loss of the SPMD switch, and this insertion loss worsens with the increase in the number of channels, severely affecting the performance of the SPMD switch. Summary of the Invention

[0003] The main objective of this application is to provide a radio frequency (RF) switching circuit designed to reduce the insertion loss of single-pole multiple-throw (SPMD) switches in RF circuits.

[0004] To achieve the above objectives, this application proposes a radio frequency (RF) switch circuit, which includes:

[0005] A passive structural device, the passive structural device including multiple switch access ports, each switch access port of the passive structural device being connected to a corresponding switch module;

[0006] A switch module, comprising at least one radio frequency switch and a function maintenance unit connected in parallel, wherein one end of the radio frequency switch is connected to the switch access port and the other end of the radio frequency switch is connected to the switch port;

[0007] The function maintenance unit is used to maintain the function of passive devices.

[0008] Optionally, the function maintenance unit includes a function maintenance switch.

[0009] If the RF switch is detected to change from an open state to a closed state, the function in the switch module that does not contain the RF switch in the closed state will be maintained to keep the switch closed, so as to connect the circuit path to realize the function of the passive device.

[0010] Optionally, the passive structural device includes a transformer balun, the plurality of switching modules include a first switching module and a second switching module, and the function maintenance unit includes a function maintenance switch.

[0011] The input terminal of the transformer balun is connected to the output terminal of the differential radio frequency circuit;

[0012] In the first switching module, one end of the radio frequency switch is connected to the first output terminal of the transformer balun, and the other end of the radio frequency switch is connected to the corresponding first switch port. In the first switching module, one end of the function maintenance switch is connected to the first output terminal of the transformer balun, and the other end of the function maintenance switch is grounded.

[0013] In the second switching module, one end of the radio frequency switch is connected to the second output terminal of the transformer balun, and the other end of the radio frequency switch is connected to the corresponding second switch port. In the second switching module, one end of the function maintenance switch is connected to the second output terminal of the transformer balun, and the other end of the function maintenance switch is grounded.

[0014] Optionally, if the radio frequency switch in the first switch module is detected to change from an open state to a closed state, the function maintenance switch in the second switch module is closed to connect the circuit path for realizing the transformer balun function; if the radio frequency switch in the second switch module is detected to change from an open state to a closed state, the function maintenance switch in the first switch module is closed to connect the circuit path for realizing the transformer balun function.

[0015] Optionally, the passive structural device includes a two-wire coupler, the plurality of switching modules include a third switching module and a fourth switching module, and the function maintenance unit includes a first function maintenance impedance and a function maintenance switch.

[0016] In the third switch module, one end of the RF switch is connected to the first input terminal of the two-wire coupler, and the other end of the RF switch is connected to the corresponding third switch port. In the third switch module, one end of the function sustain switch is connected to the first input terminal of the two-wire coupler, and the other end of the function sustain switch is connected to the corresponding first function sustain impedance.

[0017] In the fourth switch module, one end of the RF switch is connected to the second input terminal of the two-wire coupler, and the other end of the RF switch is connected to the corresponding fourth switch port. In the fourth switch module, one end of the function sustain switch is connected to the second input terminal of the two-wire coupler, and the other end of the function sustain switch is connected to the corresponding second function sustain impedance.

[0018] Optionally, if the radio frequency switch in the third switch module is detected to change from an open state to a closed state, the function maintenance switch in the fourth switch module is closed to connect the circuit path for realizing the function of the two-wire coupler; if the radio frequency switch in the fourth switch module is detected to change from an open state to a closed state, the function maintenance switch in the third switch module is closed to connect the circuit path for realizing the function of the two-wire coupler.

[0019] Optionally, the passive structural device includes a three-wire coupler, the plurality of switching modules include a fifth switching module, a sixth switching module, and a seventh switching module, and the function maintenance unit includes a second function maintenance impedance and a function maintenance switch.

[0020] In the fifth switch module, one end of the radio frequency switch is connected to the first input terminal of the three-wire coupler, and the other end of the radio frequency switch is connected to the corresponding fifth switch port. In the fifth switch module, one end of the function maintenance switch is connected to the first input terminal of the three-wire coupler, and the other end of the function maintenance switch is connected to the corresponding second function maintenance impedance.

[0021] In the sixth switch module, one end of the radio frequency switch is connected to the second input terminal of the three-wire coupler, and the other end of the radio frequency switch is connected to the corresponding sixth switch port. In the sixth switch module, one end of the function maintenance switch is connected to the second input terminal of the three-wire coupler, and the other end of the function maintenance switch is connected to the corresponding second function maintenance impedance.

[0022] In the seventh switch module, one end of the RF switch is connected to the third input terminal of the three-wire coupler, and the other end of the RF switch is connected to the corresponding seventh switch port. In the seventh switch module, one end of the function maintenance switch is connected to the third input terminal of the three-wire coupler, and the other end of the function maintenance switch is connected to the corresponding second function maintenance impedance.

[0023] Optionally, if the RF switch in the fifth switch module is detected to change from an open state to a closed state, the function maintenance switches in the sixth and seventh switch modules are closed to connect the circuit path for realizing the three-wire coupler function; if the RF switch in the sixth switch module is detected to change from an open state to a closed state, the function maintenance switches in the fifth and seventh switch modules are closed to connect the circuit path for realizing the three-wire coupler function; if the RF switch in the seventh switch module is detected to change from an open state to a closed state, the function maintenance switches in the fifth and sixth switch modules are closed to connect the circuit path for realizing the three-wire coupler function.

[0024] To achieve the above objectives, this application also proposes a radio frequency switch device, which includes the radio frequency switch circuit described above, and will not be repeated here.

[0025] To achieve the above objectives, this application also proposes a radio frequency device, which includes the radio frequency switching device described above, and will not be repeated here.

[0026] The technical solution of this application comprises a radio frequency (RF) switch circuit consisting of a passive structural device and multiple switch modules. In this RF switch circuit, the passive structural device includes multiple switch access ports, each of which is connected to a corresponding switch module. The switch module consists of at least one RF switch and a function maintenance unit connected in parallel. One end of the RF switch is connected to the switch access port, and the other end is connected to the switch port. The function maintenance unit is used to maintain the function of the passive device. In this way, when the RF switch in one of the switching modules closes, the function maintenance unit in the switch modules that are not closed will form a path together with the closed RF switch, thereby realizing the function of the passive structure device. At this time, since different switching modules are connected to different switch access ports of the passive structure device, the parasitic capacitance of the RF switches in other switch modules that are not closed will not affect the path formed by the closed RF switch. Therefore, this application realizes that by grouping multiple RF switches in a single-pole multi-throw switch and connecting them in parallel with the function maintenance unit to form multiple switching modules, since these multiple switching modules are connected to different switch access ports of the passive structure device, the parasitic capacitance formed when each RF switch in the switching module is open will not affect the path formed when the switch in other switching modules is closed. Therefore, the insertion loss of the single-pole multi-throw switch in the RF circuit can be reduced. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the equivalent model of the on-state and off-state of a MOS switch.

[0029] Figure 2 This is a circuit functional block diagram of one embodiment of the radio frequency switch circuit in this application;

[0030] Figure 3This is a circuit functional block diagram of another embodiment of the radio frequency switch circuit in this application;

[0031] Figure 4 This is a schematic diagram of the circuit structure of an embodiment of the radio frequency switching circuit when the passive structural device in this application is a transformer balun;

[0032] Figure 5 This is a schematic diagram of the circuit structure of an embodiment of the radio frequency switching circuit when the passive structural device in this application is a two-wire coupler;

[0033] Figure 6 This is a schematic diagram of the circuit structure of an embodiment of the radio frequency switching circuit when the passive structural device in this application is a three-wire coupler.

[0034] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0035] Explanation of icon numbers:

[0036]

[0037] Detailed Implementation

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0039] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0040] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0041] Currently, switches typically experience insertion losses when connected to circuits. Taking a MOS switch as an example, refer to... Figure 1 , Figure 1 This diagram illustrates the equivalent models of a MOS switch in both its on and off states. When the MOS switch is on, a parasitic resistance R exists between its input and output terminals. ON When a MOS switch is turned off, a parasitic capacitance C exists between the input and output terminals of the switch. DS However, regardless of whether the switch is on or off, there is a parasitic capacitance C to ground at both ends of the switch. S and C D For single-pole multi-throw (SPMW) switches, all switches are connected to the same input port. This results in all parasitic capacitances from the switches to ground being connected to the input port. These parasitic capacitances will severely degrade (increase) the insertion loss of the switches. The more switching channels an SPMW switch has, the more severe the deterioration of the insertion loss.

[0042] This application discloses a radio frequency switch circuit. In one embodiment of this application, refer to... Figure 2 and Figure 3 The radio frequency switch circuit includes a passive structural device 100 and multiple switch modules 200.

[0043] The passive structural device 100 includes a common terminal and multiple switch access ports 1 to N. Each switch access port 1 to N of the passive structural device 100 is connected to a switch module 200. The switch module 200 is composed of multiple radio frequency switches L and a function maintenance unit 20A connected in parallel. One end of the radio frequency switch L is connected to the corresponding switch access port on the passive structural device 100, and the other end of the radio frequency switch L is connected to the corresponding switch port P. The function maintenance unit 20A is connected to the corresponding switch access port on the passive structural device 100 and is used to maintain the function of the passive device. Thus, in this embodiment of the application, the original single-pole multi-throw switch group is divided into multiple switch modules 200, and the multiple switch modules 200 are connected to different switch access ports of the passive structural device 100. Therefore, the multiple switch modules 200 are isolated from each other. When the RF switch L in any switch module 200 is closed, the parasitic resistance of the RF switch L in other switch modules 200 will not affect the circuit path formed after the RF switch is closed, thereby reducing the insertion loss of the single-pole multi-throw switch in the RF circuit.

[0044] As an example, the RF switch L can be at least one of the following: a MOS switch, a transistor switch, a diode switch, and a circuit module power-on / off switch.

[0045] As an example, the passive structural device 100 can be at least one of the following: a transformer balun, a two-wire coupler, and a three-wire coupler.

[0046] As an example, the function maintenance unit 20A includes a function maintenance switch S. If an RF switch L changes from an open state to a closed state, the function maintenance switch S in the switch module 200, which does not contain an RF switch L in a closed state, will be closed. This will connect the circuit path that realizes the function of the passive device, thereby reducing the insertion loss of the single-pole multi-throw switch while ensuring the function of the passive structure device 100.

[0047] As an example, refer to Figure 4 The passive structural device 100 is a transformer balun 100A, the plurality of switching modules 200 include a first switching module 201 and a second switching module 202, and the function maintenance unit 20A includes a function maintenance switch S.

[0048] The input terminal of the transformer balun 100A is connected to the output terminal of the differential RF circuit; one end of each RF switch L in the first switch module 201 is connected to the first input terminal A of the transformer balun 100A, and the other end of each RF switch L in the first switch module 201 is connected to its corresponding first switch port P1; one end of the function maintenance switch S in the first switch module 201 is connected to the first input terminal A of the transformer balun 100A, and the other end of the function maintenance switch S in the first switch module 201 is grounded; one end of each RF switch L in the second switch module 202 is connected to the second input terminal B of the transformer balun 100A, and the other end of each RF switch L in the second switch module 202 is connected to its corresponding second switch port P2; one end of the function maintenance switch S in the second switch module 202 is connected to the second input terminal B of the transformer balun 100A, and the other end of the function maintenance switch S in the second switch module 202 is grounded.

[0049] As an example, if the RF switch L in the first switch module 201 changes from an open state to a closed state, the function maintenance switch S in the second switch module 202 closes, and the four terminals of the transformer balun 100A are connected to form a circuit path for realizing the transformer balun function. Thus, when implementing the transformer balun function, since the first switch module 201 and the second switch module 202 are connected to different input terminals of the transformer balun 100A, and the circuit path for realizing the transformer balun function is generated by the closure of the RF switch L in the first switch module 201, the parasitic capacitance from each RF switch L in the second switch module 202 to ground will not affect the circuit path for realizing the transformer balun function, thereby reducing the insertion loss of the single-pole multi-throw switch when implementing the transformer balun function.

[0050] As an example, if the RF switch L in the second switch module 202 changes from an open state to a closed state, then the function-maintaining switch S in the first switch module 201 is closed, and the four terminals of the transformer balun 100A will also be connected to form a circuit path for realizing the transformer balun function. Thus, when implementing the transformer balun function, since the first switch module 201 and the second switch module 202 are connected to different input terminals of the transformer balun 100A, and the circuit path for realizing the transformer balun function is generated by the closure of the RF switch L in the second switch module 202, the parasitic capacitance from each RF switch L in the first switch module 201 to ground will not affect the circuit path for realizing the transformer balun function, thereby reducing the insertion loss of the single-pole multi-throw switch when implementing the transformer balun function.

[0051] As an example, refer to Figure 5 The passive structural device 100 is a two-wire coupler 100B, the plurality of switching modules 200 include a third switching module 203 and a fourth switching module 204, and the function maintenance unit 20A includes a first function maintenance impedance R1 and a function maintenance switch S.

[0052] The two-wire coupler 100B includes a first output terminal M1, a second output terminal M2, a first input terminal C, and a second input terminal D. In the third switch module 203, one end of each RF switch L is connected to the first input terminal C of the two-wire coupler 100B, and the other end of each RF switch L is connected to the corresponding third switch port P3. One end of the function sustaining switch S in the third switch module 203 is connected to the first input terminal C of the two-wire coupler 100B, and the other end of the function sustaining switch S is connected to the corresponding first function sustaining impedance R1. In the fourth switch module 204, one end of each RF switch L is connected to the second input terminal D of the two-wire coupler 100B, and the other end of each RF switch L is connected to the corresponding fourth switch port P4. One end of the function sustaining switch S in the fourth switch module 204 is connected to the first input terminal D of the two-wire coupler 100B, and the other end of the function sustaining switch S is connected to the corresponding first function sustaining impedance R1.

[0053] As an example, the two-wire coupler 100B can be a 3dB bridge, and the first functional sustaining impedance can be a 50-ohm impedance.

[0054] As an example, if the RF switch L in the third switch module 203 changes from an open state to a closed state, then the function-maintaining switch S in the fourth switch module 204 is closed. At this time, the first input terminal C of the two-wire coupler 100B serves as the signal input terminal, and the second input terminal D of the two-wire coupler 100B serves as the isolation terminal. The four terminals of the two-wire coupler 100B are connected to form a circuit path that realizes the function of the two-wire coupler. In this way, when implementing the function of the two-wire coupler, since the third switch module 203 and the fourth switch module 204 are respectively connected to the signal input terminal and the isolation terminal of the two-wire coupler 100B, and the circuit path that realizes the function of the two-wire coupler is generated by the closure of the RF switch L in the third switch module 203, the parasitic capacitance of each RF switch L in the fourth switch module 204 will not affect the circuit path that realizes the function of the two-wire coupler, thus reducing the insertion loss of the single-pole multi-throw switch when implementing the function of the two-wire coupler.

[0055] As an example, if the RF switch L in the fourth switch module 204 changes from an open state to a closed state, then the function-maintaining switch S in the third switch module 203 is closed. At this time, the second input terminal D of the two-wire coupler 100B serves as the signal input terminal, and the first input terminal C of the two-wire coupler 100B serves as the isolation terminal. The four terminals of the two-wire coupler 100B are connected to form a circuit path that realizes the function of the two-wire coupler. In this way, when implementing the function of the two-wire coupler, since the third switch module 203 and the fourth switch module 204 are respectively connected to the isolation terminal and the signal input terminal of the two-wire coupler 100B, and the circuit path that realizes the function of the two-wire coupler is generated by the closure of the RF switch L in the fourth switch module 204, the parasitic capacitance of each RF switch L in the third switch module 203 will not affect the circuit path that realizes the function of the two-wire coupler, thus reducing the insertion loss of the single-pole multi-throw switch when implementing the function of the two-wire coupler.

[0056] As an example, refer to Figure 6 The passive structural device 100 is a three-wire coupler 100C, the plurality of switch modules 200 include a fifth switch module 205, a sixth switch module 206 and a seventh switch module 207, and the function maintenance unit 20A includes a function maintenance switch S and a second function maintenance impedance R2.

[0057] The three-wire coupler 100C includes a first input terminal E, a second input terminal F, a third input terminal G, a first output terminal M3, a second output terminal M4, and a third output terminal M5; one end of each RF switch L in the fifth switch module 205 is connected to the first input terminal E of the three-wire coupler 100C, and the other end of each RF switch L in the fifth switch module 205 is connected to the corresponding fifth switch port P5; one end of the function maintenance switch S in the fifth switch module 205 is connected to the first input terminal E of the three-wire coupler 100C, and the other end of the function maintenance switch S in the fifth switch module 205 is connected to the corresponding second function maintenance impedance R2; one end of the RF switch L in the sixth switch module 206 is connected to the second input terminal F of the three-wire coupler 100C, and the sixth switch module 206... In the sixth switch module 206, one end of the RF switch L is connected to the corresponding sixth switch port P6. One end of the function sustaining switch S in the sixth switch module 206 is connected to the second input terminal F of the three-wire coupler 100C, and the other end of the function sustaining switch S in the sixth switch module 206 is connected to the corresponding second function sustaining impedance R2. In the seventh switch module 207, one end of the RF switch L is connected to the third input terminal G of the three-wire coupler 100C, and the other end of the RF switch L in the seventh switch module 207 is connected to the corresponding seventh switch port P7. One end of the function sustaining switch S in the seventh switch module 207 is connected to the third input terminal G of the three-wire coupler 100C, and the other end of the function sustaining switch S in the seventh switch module 207 is connected to the corresponding second function sustaining impedance R2.

[0058] As an example, the second functional sustaining impedance R2 can be a 50-ohm impedance.

[0059] As an example, if the RF switch L in the fifth switch module 205 changes from an open state to a closed state, then the function maintenance switches S in the sixth switch module 206 and the seventh switch module 207 are closed, and the six terminals of the three-wire coupler 100C are connected to form a circuit path for realizing the function of the three-wire coupler 100C. Thus, when implementing the three-wire coupler function, since the fifth switch module 205, the sixth switch module 206, and the seventh switch module 207 are respectively connected to different input terminals of the three-wire coupler 100C, and the circuit path for realizing the function of the three-wire coupler 100C is generated by the closure of the RF switch L in the fifth switch module 205, the parasitic capacitances of each RF switch L in the sixth switch module 206 and the seventh switch module 207 will not affect the circuit path for realizing the three-wire coupler function, thereby reducing the insertion loss of the single-pole multi-throw switch when implementing the three-wire coupler function.

[0060] As an example, if the RF switch L in the sixth switch module 206 changes from an open state to a closed state, then the function maintenance switch S in the fifth switch module 205 and the seventh switch module 207 is closed, and the six terminals of the three-wire coupler 100C are connected to form a circuit path for realizing the three-wire coupler function. Thus, when implementing the three-wire coupler function, since the fifth switch module 205, the sixth switch module 206, and the seventh switch module 207 are respectively connected to different input terminals of the three-wire coupler 100C, and the circuit path for realizing the three-wire coupler function is generated by the closure of the RF switch L in the sixth switch module 206, the parasitic capacitance of each RF switch L in the fifth switch module 205 and the seventh switch module 207 will not affect the circuit path for realizing the three-wire coupler function, thereby reducing the insertion loss of the single-pole multi-throw switch when implementing the three-wire coupler function.

[0061] As an example, if the RF switch L in the seventh switch module 207 changes from an open state to a closed state, then the function maintenance switch S in the fifth switch module 205 and the sixth switch module 206 is closed, and the six terminals of the three-wire coupler 100C are connected to form a circuit path for realizing the three-wire coupler function. Thus, when implementing the three-wire coupler function, since the fifth switch module 205, the sixth switch module 206, and the seventh switch module 207 are respectively connected to different input terminals of the three-wire coupler 100C, and the circuit path for realizing the three-wire coupler 100C function is generated by the closure of the RF switch L in the seventh switch module 207, the parasitic capacitance of each RF switch L in the fifth switch module 205 and the sixth switch module 206 will not affect the circuit path for realizing the three-wire coupler function, thereby reducing the insertion loss of the single-pole multi-throw switch when implementing the three-wire coupler function.

[0062] In addition, this application also provides a radio frequency switch device, which includes the radio frequency switch circuit described above. It is understood that since the radio frequency switch circuit is used in the radio frequency switch device, the embodiments of the radio frequency switch device include all the technical solutions of all the embodiments of the radio frequency switch circuit described above, and the technical effects achieved are exactly the same, so they will not be repeated here.

[0063] In addition, this application also provides a radio frequency device, which includes the radio frequency switch device described above. It is understood that since the radio frequency switch device is used in the radio frequency device, the embodiments of the radio frequency device include all the technical solutions of all the embodiments of the radio frequency switch device described above, and the technical effects achieved are exactly the same, so they will not be repeated here.

[0064] The above description is merely a preferred embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the content of this application's specification and drawings under the concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A radio frequency switching circuit, characterized in that, The radio frequency switch circuit includes: A passive structural device, the passive structural device including multiple switch access ports, each switch access port of the passive structural device being connected to a corresponding switch module; A switch module, comprising at least one radio frequency switch and a function maintenance unit connected in parallel, wherein one end of the radio frequency switch is connected to the switch access port and the other end of the radio frequency switch is connected to the switch port; The function maintenance unit is used to maintain the function of the passive device; The function maintenance unit includes a function maintenance switch. If the RF switch is detected to change from an open state to a closed state, the function in the switch module that does not contain the RF switch in the closed state will be maintained to keep the switch closed, so as to connect the circuit path to realize the function of the passive device.

2. The radio frequency switching circuit as described in claim 1, characterized in that, The passive structural device includes a transformer balun, the plurality of switching modules include a first switching module and a second switching module, and the function maintenance unit includes a function maintenance switch. The input terminal of the transformer balun is connected to the output terminal of the differential radio frequency circuit; In the first switching module, one end of the radio frequency switch is connected to the first output terminal of the transformer balun, and the other end of the radio frequency switch is connected to the corresponding first switch port. In the first switching module, one end of the function maintenance switch is connected to the first output terminal of the transformer balun, and the other end of the function maintenance switch is grounded. In the second switching module, one end of the radio frequency switch is connected to the second output terminal of the transformer balun, and the other end of the radio frequency switch is connected to the corresponding second switch port. In the second switching module, one end of the function maintenance switch is connected to the second output terminal of the transformer balun, and the other end of the function maintenance switch is grounded.

3. The radio frequency switching circuit as described in claim 2, characterized in that, If the radio frequency switch in the first switch module is detected to change from an open state to a closed state, then the function maintenance switch in the second switch module is closed to connect the circuit path that realizes the transformer balun function. If the radio frequency switch in the second switch module is detected to change from an open state to a closed state, the function maintenance switch in the first switch module is closed to connect the circuit path that realizes the transformer balun function.

4. The radio frequency switching circuit as described in claim 1, characterized in that, The passive structural device includes a two-wire coupler; the plurality of switching modules include a third switching module and a fourth switching module; and the function maintenance unit includes a first function maintenance impedance and a function maintenance switch. In the third switch module, one end of the RF switch is connected to the first input terminal of the two-wire coupler, and the other end of the RF switch is connected to the corresponding third switch port. In the third switch module, one end of the function sustain switch is connected to the first input terminal of the two-wire coupler, and the other end of the function sustain switch is connected to the corresponding first function sustain impedance. In the fourth switch module, one end of the RF switch is connected to the second input terminal of the two-wire coupler, and the other end of the RF switch is connected to the corresponding fourth switch port. In the fourth switch module, one end of the function sustain switch is connected to the second input terminal of the two-wire coupler, and the other end of the function sustain switch is connected to the corresponding second function sustain impedance.

5. The radio frequency switching circuit as described in claim 4, characterized in that, If the radio frequency switch in the third switch module is detected to change from an open state to a closed state, then the function maintenance switch in the fourth switch module is closed to connect the circuit path that realizes the function of the two-wire coupler. If the radio frequency switch in the fourth switch module is detected to change from an open state to a closed state, the function maintenance switch in the third switch module is closed to connect the circuit path that realizes the function of the two-wire coupler.

6. The radio frequency switching circuit as described in claim 1, characterized in that, The passive structural device includes a three-wire coupler; the plurality of switching modules include a fifth switching module, a sixth switching module, and a seventh switching module; and the function maintenance unit includes a second function maintenance impedance and a function maintenance switch. In the fifth switch module, one end of the radio frequency switch is connected to the first input terminal of the three-wire coupler, and the other end of the radio frequency switch is connected to the corresponding fifth switch port. In the fifth switch module, one end of the function maintenance switch is connected to the first input terminal of the three-wire coupler, and the other end of the function maintenance switch is connected to the corresponding second function maintenance impedance. In the sixth switch module, one end of the radio frequency switch is connected to the second input terminal of the three-wire coupler, and the other end of the radio frequency switch is connected to the corresponding sixth switch port. In the sixth switch module, one end of the function maintenance switch is connected to the second input terminal of the three-wire coupler, and the other end of the function maintenance switch is connected to the corresponding second function maintenance impedance. In the seventh switch module, one end of the RF switch is connected to the third input terminal of the three-wire coupler, and the other end of the RF switch is connected to the corresponding seventh switch port. In the seventh switch module, one end of the function maintenance switch is connected to the third input terminal of the three-wire coupler, and the other end of the function maintenance switch is connected to the corresponding second function maintenance impedance.

7. The radio frequency switching circuit as described in claim 6, characterized in that, If the radio frequency switch in the fifth switch module is detected to change from an open state to a closed state, then the function maintenance switches in the sixth and seventh switch modules are closed to connect the circuit path that realizes the function of the three-wire coupler. If the radio frequency switch in the sixth switch module is detected to change from an open state to a closed state, then the function maintenance switches in the fifth switch module and the seventh switch module are closed to connect the circuit path that realizes the function of the three-wire coupler. If the radio frequency switch in the seventh switch module is detected to change from an open state to a closed state, then the function maintenance switches in the fifth switch module and the sixth switch module are closed to connect the circuit path that realizes the function of the three-wire coupler.

8. The radio frequency switching circuit according to any one of claims 1 to 7, characterized in that, The radio frequency switch includes at least one of the following: a MOS switch, a transistor switch, a diode switch, and a circuit module power-on / off switch.

9. The radio frequency switching circuit as described in claim 1, characterized in that, The passive structural device includes at least one of the following: a transformer balun, a two-wire coupler, and a three-wire coupler.

10. A radio frequency switching device, characterized in that, The radio frequency switching device includes the radio frequency switching circuit as described in any one of claims 1-9.

11. A radio frequency device, characterized in that, The radio frequency device includes the radio frequency switching device as described in claim 10.

Images