Radio frequency switch and radio frequency front-end module

Abstract

The utility model discloses a radio frequency switch and a radio frequency front-end module, the radio frequency switch comprises N first transistors, N first resistors and an adjustable capacitor unit which are sequentially connected in series, and N is an integer greater than 1. The N first resistors are connected in parallel with the N first transistors in a one-to-one correspondence manner. And the adjustable capacitor unit is connected in parallel with one specified resistor in the N first resistors so as to form a suppression circuit together with the specified resistor, and the suppression circuit is used for suppressing a harmonic signal in a radio frequency signal passing through the radio frequency switch. According to the radio frequency switch, the suppression effect on harmonic signals can be achieved by arranging the adjustable capacitor unit, and then the transmission quality of radio frequency signals is guaranteed.

Description

Technical Field

[0001] This application relates to the field of radio frequency technology, and more specifically, to a radio frequency switch and a radio frequency front-end module. Background Technology

[0002] Currently, radio frequency (RF) front-end modules are widely used in wireless communication, the Internet of Things (IoT), smart homes, and other fields. They can process RF signals (e.g., power amplification, modulation and demodulation) to complete the tasks of receiving and transmitting RF signals.

[0003] In existing RF front-end modules, RF switches are an important component. They are used to switch the transmission of RF signals in different frequency bands to ensure the normal operation of various chips and components in the RF front-end module. Of course, RF switches can also be placed in the tuning circuit to achieve tuning operations on the RF signals.

[0004] Specifically, an RF switch may include multiple transistors. During the process of an RF signal passing through an RF switch, the parasitic capacitance of the transistors themselves will cause harmonics (e.g., second-order harmonics and third-order harmonics) to be generated, which will affect the transmission quality of the RF signal. Utility Model Content

[0005] This application provides an embodiment of a radio frequency switch and a radio frequency front-end module.

[0006] According to a first aspect of this application, an embodiment of this application provides a radio frequency (RF) switch, which includes N first transistors, N first resistors, and an adjustable capacitor unit connected in series, wherein N is an integer greater than 1. The N first resistors are connected in parallel with the N first transistors in a one-to-one correspondence. The adjustable capacitor unit is connected in parallel with one of the N first resistors, forming a suppression circuit together with the specified resistor. The suppression circuit is used to suppress harmonic signals in the radio frequency signal passing through the RF switch.

[0007] In some possible embodiments, the adjustable capacitor unit includes a second transistor, which is a field-effect transistor. The gate of the second transistor is connected to a first terminal of a specified resistor; the source and drain of the second transistor are connected to form a common terminal, which is connected to a second terminal of the specified resistor.

[0008] In some possible embodiments, the adjustable capacitor unit further includes a third transistor, a second resistor, and a third resistor; the third transistor and the second transistor are connected in series, and the third transistor is a field-effect transistor; the source and drain of the third transistor are connected to form a common terminal, the common terminal of the third transistor and the common terminal of the second transistor are connected, and the gate of the third transistor is connected to the second terminal of the specified resistor; the second resistor and the second transistor are connected in parallel, and the third resistor and the third transistor are connected in parallel.

[0009] In some possible embodiments, the adjustable capacitor unit further includes a third transistor, a second resistor, and a third resistor; the third transistor and the second transistor are connected in series, and the third transistor is a field-effect transistor; the source and drain of the third transistor are connected to form a common terminal, the common terminal of the third transistor is connected to the first terminal of the specified resistor, and the gate of the third transistor and the gate of the second transistor are connected in parallel; the second resistor and the second transistor are connected in parallel, and the third resistor and the third transistor are connected in parallel.

[0010] In some possible embodiments, the adjustable capacitor unit includes one second transistor, which is connected in parallel across a specified resistor.

[0011] In some possible embodiments, the adjustable capacitor unit includes multiple second transistors; the multiple second transistors are connected in series and then connected in parallel across a specified resistor; in two adjacent second transistors, the common terminal of one second transistor is connected to the gate of the other second transistor.

[0012] In some possible embodiments, the gates of the second transistor and the third transistor are not biased.

[0013] In some possible embodiments, the resistance value of the second resistor is greater than or equal to 10kΩ; the resistance value of the third resistor is greater than or equal to 10kΩ.

[0014] In some possible embodiments, the radio frequency switch is further provided with a first connection terminal and a second connection terminal, and N first transistors are connected in series between the first connection terminal and the second connection terminal in a first direction; the first direction is the direction from the first connection terminal to the second connection terminal; the number of adjustable capacitor units and designated resistors is M, where M is less than or equal to N; the M designated resistors are the first M resistors of the N first resistors in the first direction, where the first direction is the direction from the first connection terminal to the second connection terminal.

[0015] In some possible embodiments, the radio frequency switch further includes a first connection terminal and a second connection terminal. N first transistors are connected in series between the first connection terminal and the second connection terminal in a first direction; the first direction is the direction from the first connection terminal to the second connection terminal. The number of adjustable capacitor units and designated resistors are both K*2, where K*2 is less than or equal to N. The K*2 designated resistors include K first designated resistors and K second designated resistors. The K first designated resistors are the first K resistors of the N first resistors in the first direction, where the first direction is the direction from the first connection terminal to the second connection terminal. The K second designated resistors are the first K resistors of the N first resistors in the second direction, where the second direction is the direction from the second connection terminal to the first connection terminal.

[0016] In some possible embodiments, the element size of the second transistor is smaller than that of the first transistor.

[0017] In some possible embodiments, the first transistor is a field-effect transistor; the first resistor is connected between the source and drain of the first transistor; the resistance value of the first resistor is greater than or equal to 10kΩ.

[0018] In some possible embodiments, N first transistors are connected in series between the first connection terminal and the second connection terminal to form a series branch; the radio frequency switch also includes a parallel branch, one end of which is connected to one end of the series branch used to connect the tuning element, and the other end of the parallel branch is grounded.

[0019] This application provides a radio frequency switch, which may include N first transistors, N first resistors and an adjustable capacitor unit connected in series. The adjustable capacitor unit is connected in parallel with one of the N first resistors to form a suppression circuit together with the specified resistor. The suppression circuit is used to suppress harmonic signals in the radio frequency signal passing through the radio frequency switch.

[0020] Specifically, the adjustable capacitor unit and the specified resistor together constitute an RC phase-shifting circuit (i.e., a suppression circuit). When a portion of the harmonic signal passes through this RC phase-shifting circuit, its phase shifts by at least 90 degrees. Ideally, the signal phase can be shifted by 180 degrees. Therefore, when the phase-shifted portion of the signal is combined with the unshifted portion of the harmonic signal, the two signals can cancel each other out, thus suppressing the harmonic signal. In summary, the RF switch in this application can achieve harmonic signal suppression by setting an adjustable capacitor unit, thereby ensuring the transmission quality of the RF signal.

[0021] According to a second aspect of this application, embodiments of this application also provide a radio frequency (RF) switch. The RF switch has a first connection terminal and a second connection terminal. The RF switch includes N first transistors, N first resistors, and M adjustable capacitor units. The N first transistors are connected in series between the first connection terminal and the second connection terminal, where N is an integer greater than 1. The N first resistors are connected in parallel with the N first transistors in a one-to-one correspondence. The M adjustable capacitor units are connected in parallel with M designated resistors from the N first resistors in a one-to-one correspondence; wherein the M designated resistors are the first M resistors of the N first resistors in a first direction, where M is less than or equal to N, and the first direction is the direction from the first connection terminal to the second connection terminal.

[0022] This application provides a radio frequency switch, which may include N first transistors, N first resistors and M adjustable capacitor units connected in series, wherein the M adjustable capacitor units are connected in parallel with M designated resistors among the N first resistors.

[0023] Specifically, each adjustable capacitor unit and its corresponding designated resistor together constitute an RC phase-shifting circuit (i.e., a suppression circuit). When a portion of the harmonic signal passes through this RC phase-shifting circuit, the phase of the signal will shift by at least 90 degrees. Ideally, the signal phase can be shifted by 180 degrees after passing through the RC phase-shifting circuit. Therefore, when the phase-shifted portion of the signal is combined with the unshifted portion of the harmonic signal, the two signals can cancel each other out, thereby achieving the suppression of the harmonic signal.

[0024] Furthermore, when M is greater than 1, multiple adjustable capacitor units and corresponding designated resistors together constitute multiple RC suppression circuits, which can further improve the suppression effect on harmonic signals. In summary, the RF switch in this application can achieve the suppression effect on harmonic signals by setting M adjustable capacitor units, thereby ensuring the transmission quality of RF signals.

[0025] According to a third aspect of this application, embodiments of this application also provide a radio frequency switch, which has a first connection terminal and a second connection terminal. The radio frequency switch includes N first transistors, N first resistors, and K*2 adjustable capacitor units. The N first transistors are connected in series between the first connection terminal and the second connection terminal, where N is an integer greater than 1. The N first resistors are connected in parallel with the N first transistors in a one-to-one correspondence. The K*2 adjustable capacitor units are connected in parallel with K*2 designated resistors among the N first resistors in a one-to-one correspondence; wherein K*2 is less than or equal to N, and the K*2 designated resistors include K first designated resistors and K second designated resistors. The K first designated resistors are the first K resistors of the N first resistors in a first direction, where the first direction is from the first connection terminal to the second connection terminal; the K second designated resistors are the first K resistors of the N first resistors in a second direction, where the second direction is from the second connection terminal to the first connection terminal.

[0026] This application provides a radio frequency switch, which may include N first transistors, N first resistors and K*2 adjustable capacitor units connected in series, wherein the K*2 adjustable capacitor units are connected in parallel with K*2 designated resistors among the N first resistors.

[0027] Specifically, each adjustable capacitor unit and its corresponding designated resistor together constitute an RC phase-shifting circuit (i.e., a suppression circuit). When a portion of the harmonic signal passes through this RC phase-shifting circuit, the phase of the signal will shift by at least 90 degrees. Ideally, the signal phase can be shifted by 180 degrees after passing through the RC phase-shifting circuit. Therefore, when the phase-shifted portion of the signal is combined with the unshifted portion of the harmonic signal, the two signals can cancel each other out, thereby achieving the suppression of the harmonic signal.

[0028] Furthermore, since K*2 is greater than 1, this indicates that the RF switch includes multiple adjustable capacitor units. These multiple adjustable capacitor units, together with corresponding designated resistors, can form multiple RC suppression circuits to further improve the suppression effect on harmonic signals. In summary, the RF switch in this application can achieve the suppression effect on harmonic signals by setting K*2 adjustable capacitor units, thereby ensuring the transmission quality of RF signals.

[0029] According to a fourth aspect of this application, embodiments of this application also provide a radio frequency front-end module, which includes the radio frequency switch described above.

[0030] In some possible embodiments, the RF front-end module is provided with an antenna port for connecting an antenna; the RF front-end module includes multiple parallel tuning branches; each tuning branch includes an RF switch and a tuning element connected in series; one end of the tuning branch is connected to the antenna port, and the other end is grounded.

[0031] In some possible embodiments, the RF front-end module is provided with a signal port and an antenna port for connecting an antenna; the RF front-end module includes multiple parallel tuning branches; each tuning branch includes an RF switch and a tuning element, the RF switch and the tuning element being connected in series; one end of the tuning branch is connected to the antenna port, and the other end is connected to the signal port. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a radio frequency front-end module provided in an embodiment of this application.

[0034] Figure 2 This is another structural schematic diagram of the radio frequency front-end module provided in the embodiments of this application.

[0035] Figure 3 This is a schematic diagram of the first structure of the radio frequency switch provided in the first embodiment of this application.

[0036] Figure 4 This is a schematic diagram of a second structure of the radio frequency switch provided in the first embodiment of this application.

[0037] Figure 5 This is a schematic diagram of the third structure of the radio frequency switch provided in the first embodiment of this application.

[0038] Figure 6 This is a schematic diagram of the fourth structure of the radio frequency switch provided in the first embodiment of this application.

[0039] Figure 7 This is a schematic diagram of the fifth structure of the radio frequency switch provided in the first embodiment of this application.

[0040] Figure 8 This is a schematic diagram of the sixth structure of the radio frequency switch provided in the first embodiment of this application.

[0041] Figure 9 This is a schematic diagram of the component dimensions of the first transistor provided in the first embodiment of this application.

[0042] Figure 10 This is a schematic diagram of the seventh structure of the radio frequency switch provided in the first embodiment of this application.

[0043] Figure 11This is a schematic diagram of the eighth structure of the radio frequency switch provided in the first embodiment of this application.

[0044] Figure 12 This is a schematic diagram of the structure of the radio frequency switch provided in the second embodiment of this application.

[0045] Figure 13 This is a schematic diagram of the structure of the radio frequency switch provided in the third embodiment of this application. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0047] This application provides a radio frequency (RF) switch 100 and an RF front-end module 200 configured with the RF switch 100. The RF front-end module 200 is a component that integrates two or more discrete devices, such as an RF switch, a low-noise amplifier, a filter, a duplexer, and a power amplifier, into a single independent module, thereby improving integration and hardware performance while miniaturizing the size. Specifically, the RF front-end module 200 can be applied to wireless communication devices such as smartphones, tablets, and smartwatches to achieve the reception and transmission of RF signals.

[0048] Furthermore, with the development of 5G technology, the requirements for the performance of radio frequency front-end modules are becoming increasingly stringent. The technical solution in this application can be applied to 5G radio frequency front-end modules to improve the communication performance of 5G communication equipment.

[0049] Please see Figure 1 The RF front-end module 200 may be provided with an antenna port 201 for connecting the antenna ANT. The RF front-end module 200 may include multiple parallel tuning branches 203, wherein each tuning branch 203 may include an RF switch 100 and a tuning element 210, which are connected in series. One end of the tuning branch 203 is connected to the antenna port 201, and the other end is grounded.

[0050] The tuning element 210 is used to adjust the output power of the radio frequency signal so that the antenna has high radiated power in any frequency band. In some possible embodiments, the tuning element 210 may be a single capacitor or a single inductor; in other possible embodiments, the tuning element 210 may also be a matching circuit composed of a capacitor and an inductor. Specifically, the tuning elements 210 included in different tuning branches 203 may adopt different hardware parameters so that when the radio frequency switch 100 in different tuning branches 203 is in the on state, different tuning effects on the radio frequency signal can be achieved.

[0051] Please see Figure 2 The RF front-end module 200 may include a signal port 205 and an antenna port 201 for connecting an antenna. The RF front-end module 200 may include multiple parallel tuning branches 203. Each tuning branch 203 may include an RF switch 100 and a tuning element 210, which are connected in series. One end of the tuning branch 203 is connected to the antenna port 201, and the other end is connected to the signal port 205. The tuning element 210 can be referred to the relevant description in the above embodiments, and will not be repeated here.

[0052] exist Figure 1 and Figure 2 In the embodiment shown, the radio frequency switch 100 may include a series branch (not shown) and a parallel branch (not shown), wherein the common terminal formed by the series branch and the parallel branch is connected to one end of the tuning element 210, and the other end of the tuning element 210 is connected to the antenna port 201.

[0053] exist Figure 1 and Figure 2 In the illustrated embodiment, multiple tuning branches 203 are located between the signal port 205 and the antenna port 201. The signal port 205 can be used to connect the transmit link and / or receive link in the RF front-end module. On one hand, the RF signal received by the antenna ANT can be transmitted to the receive link in the RF front-end module via the antenna port 201 and the signal port 205; on the other hand, the RF signal processed by the transmit link in the RF front-end module can be transmitted to the antenna ANT via the signal port 205 and the antenna port 201. The RF front-end module 200 can select and activate the corresponding tuning branch 203 according to the frequency of the currently transmitted or received signal, thereby achieving impedance matching for multiple RF signals of different frequency bands. Specifically, since the output impedance of the transmit link is constant, while the input impedance of the antenna varies greatly with frequency, multiple tuning branches 203 need to be set between the transmit link and the antenna to achieve impedance matching between the transmit link and the antenna, so that RF signals of different frequency bands can achieve high radiated power during transmission.

[0054] Specifically, the transmit link may include components such as power amplifiers, switches, filters / duplexers / multiplexers, etc., and the receive link may include components such as low-noise amplifiers, switches, filters / duplexers / multiplexers, etc. The transmit and receive links may share at least some components (e.g., switches, filters / duplexers / multiplexers), or they may not share components; this application does not impose any limitations on this.

[0055] Please see Figure 3 The first embodiment of this application provides a radio frequency (RF) switch 100, which may include N first transistors 120, N first resistors 140, and an adjustable capacitor unit 160 connected in series. N is an integer greater than 1. Specifically, N can be equal to 4, 6, 8, 10, 11, etc. In some possible embodiments, the developer can determine the value of N based on the voltage across the RF switch 100 and the withstand voltage of a single first transistor 120. For example, if the voltage across the RF switch 100 is 45V and the withstand voltage of a single first transistor 120 is 6V, then N can be 8.

[0056] N first resistors 140 are connected in parallel with N first transistors 120 in a one-to-one correspondence. Each adjustable capacitor unit 160 is connected in parallel with one of the designated resistors 1410 among the N first resistors 140 to form a suppression circuit together with the designated resistor 1410. The suppression circuit is used to suppress harmonic signals in the radio frequency signal passing through the radio frequency switch 100. It should be noted that "designated resistor" and "first resistor" are only different in name and have no difference in hardware essence. For the convenience of describing the circuit structure, this application refers to the first resistor connected in parallel with the adjustable capacitor unit 160 as the "designated resistor".

[0057] It should also be noted that a designated resistor 1410 refers to a resistor connected in parallel across the first transistor 120. On a circuit layout, a designated resistor 1410 can be represented as a single resistor or as a resistor network formed by multiple resistors connected in series and parallel. For example, if two resistors are connected in series and then in parallel across the first transistor 120, the structure formed by these two resistors in series is a designated resistor 1410 in this application.

[0058] It is easy to understand that the adjustable capacitor unit 160 and the designated resistor 1410 can together form an RC phase-shifting circuit (i.e., a suppression circuit). When a portion of the harmonic signal passes through this RC phase-shifting circuit, the phase of the signal will shift by at least 90 degrees. Ideally, the signal phase can be shifted by 180 degrees after passing through the RC phase-shifting circuit. Therefore, when the phase-shifted portion of the signal is combined with the unshifted portion of the harmonic signal, the two signals can cancel each other out, thereby achieving the suppression of the harmonic signal. In summary, the RF switch 100 in this application can achieve the suppression effect of harmonic signals by setting the adjustable capacitor unit 160, thereby ensuring the transmission quality of the RF signal.

[0059] The specific implementation of the radio frequency switch 100 is explained below.

[0060] In this embodiment, the RF switch 100 may have a first connection terminal 102 and a second connection terminal 104, and N first transistors 120 are sequentially connected in series between the first connection terminal 102 and the second connection terminal 104 to form a series branch 106. Specifically, when the RF switch 100 is configured in Figure 1 In the RF front-end module 200 shown, the first connection terminal 102 can be connected to the tuning element 210, and the second connection terminal 104 is grounded. When the RF switch 100 is configured in... Figure 2 In the RF front-end module 200 shown, the first connection terminal 102 can be connected to the tuning element 210, and the second connection terminal 104 is connected to the signal port 205.

[0061] exist Figure 3 In the illustrated embodiment, the RF switch 100 may further include a parallel branch 108, one end of which is connected to one end of the series branch 106 for connecting the tuning element 210 (i.e., Figure 3 The first connection terminal 102 in the circuit is connected to the ground at the other end of the parallel branch 108.

[0062] Please see Figure 4 The parallel branch 108 may include K series-connected switching transistor units 1080, where K can be equal to 2, 4, 6, 8, 9, etc. Specifically, each switching transistor unit 1080 may be a transistor, such as a field-effect transistor.

[0063] In some possible embodiments, there may be multiple parallel branches 108, with one end of each parallel branch 108 connected to a series branch 106, for example, connected to one end of a series branch 106, or connected between two adjacent first transistors 120 in a series branch 106. The other end of the parallel branch 108 is grounded. This embodiment does not limit the specific implementation of the parallel branch 108.

[0064] In this embodiment, the first transistor 120 can be a field-effect transistor, such as a junction field-effect transistor (JFET), a metal-oxide-semiconductor field-effect transistor (MOSFET), a high-electron mobility transistor (HEMT), a pseudo-high-electron-mobility transistor (PHEMT), etc. Of course, the first transistor 120 can also be other types of transistors; this embodiment does not impose specific limitations. Optionally, the first transistor 120 can be formed on a conventional silicon substrate or on a silicon-on-insulator (SOI) substrate.

[0065] exist Figure 4 In the illustrated embodiment, the RF switch 100 is provided with a bias terminal 105, which is used to input a bias voltage Vb1. The bias voltage Vb1 is used to turn on or off N first transistors 120. For example, taking an N-type field-effect transistor as an example, when the bias voltage Vb1 is high, the N first transistors 120 are in the on state; when the bias voltage Vb1 is low, the N first transistors 120 are in the off state.

[0066] Specifically, the RF switch 100 may further include a bias unit 130, which is connected between the gates of the N first transistors 120 and the bias terminal 105. The bias unit 130 is used to reduce the amplitude of the bias voltage Vb1 so that the bias voltage Vb1 can match the operating voltage of the first transistors 120, thereby ensuring the smooth operation of the first transistors 120. As one implementation, the bias unit 130 may include multiple resistors; this embodiment does not limit the implementation method of the bias unit 130.

[0067] In this embodiment, N first resistors 140 are connected in parallel with N first transistors 120 in a one-to-one correspondence. When the first transistor 120 is a field-effect transistor, the first resistor 140 is connected between the source and drain of the first transistor 120. In some possible embodiments, the resistance value of the first resistor 140 can be greater than or equal to 10kΩ. For example, the resistance value of the first resistor 140 can be 10kΩ, 12kΩ, 15kΩ, etc.

[0068] The implementation of the adjustable capacitor unit 160 is explained below.

[0069] Please see Figure 5The adjustable capacitor unit 160 may include a second transistor 1610, which is a field-effect transistor. The gate of the second transistor 1610 is connected to the first terminal 1412 of the designated resistor 1410. The source and drain of the second transistor 1610 are connected to form a common terminal 1612, which is connected to the second terminal 1414 of the designated resistor 1410. It should be noted that the positions of the first terminal 1412 and the second terminal 1414 of the designated resistor 1410 can be interchanged. Figure 5 In the illustrated embodiment, the end of the specified resistor 1410 furthest from the second connection terminal 104 is designated as the first terminal 1412. In some other possible embodiments, the end of the specified resistor 1410 closest to the second connection terminal 104 may also be designated as the first terminal 1412.

[0070] Therefore, the adjustable capacitor unit 160 in this embodiment is implemented using a field-effect transistor with source and drain shorted. This field-effect transistor can be equivalent to an adjustable capacitor with an adjustable capacitance value. The adjustable capacitor and the specified resistor 1410 are connected in parallel to form an RC phase-shifting circuit to achieve the effect of suppressing harmonic signals.

[0071] Specifically, when all the first transistors 120 between the first connection terminal 102 and the second connection terminal 104 are turned on, there is a certain voltage difference between the source and drain of each first transistor 120. There is also a certain voltage difference between the two ends (gate and common terminal 1612) of the second transistor 1610 connected in parallel with the first transistor 120. The capacitance of the PN junction between the gate and the common terminal 1612 of the second transistor 1610 will change with the voltage difference, thereby forming an adjustable capacitor that automatically follows the change of the radio frequency signal voltage.

[0072] In some possible embodiments, the adjustable capacitor unit 160 includes only one second transistor 1610, which is connected in parallel across the designated resistor 1410. That is, the second transistor 1610 is directly connected in parallel with the designated resistor 1410. This embodiment only requires one second transistor 1610 to achieve the suppression of harmonic signals, which can reduce the hardware cost of the RF switch 100.

[0073] In some other possible embodiments, the adjustable capacitor unit 160 includes multiple second transistors 1610, for example, 2, 3, 4, etc. The multiple second transistors 1610 are connected in series in the same direction and then connected in parallel across the designated resistor 1410. In adjacent pairs of second transistors 1610, the common terminal of one second transistor 1610 is connected to the gate of the other second transistor 1610. Specifically, the multiple second transistors 1610 can be connected in series with their gates facing the first connection terminal 102 and their common terminals facing the second connection terminal 104, or with their common terminals facing the first connection terminal 102 and their gates facing the second connection terminal 104.

[0074] Please see Figure 6 The adjustable capacitor unit 160 comprises multiple second transistors 1610 connected in series, wherein there are two second transistors 1610. This embodiment allows for more flexible adjustment of the equivalent capacitance value of the adjustable capacitor unit 160 by using multiple second transistors 1610 connected in series. Furthermore, it ensures that even if a single second transistor 1610 fails (e.g., short-circuit), the remaining second transistors 1610 can still function as an adjustable capacitor, thus guaranteeing the normal operation of the adjustable capacitor unit 160.

[0075] In some possible embodiments, the adjustable capacitor unit 160 may further include a third transistor 1630, a second resistor 1650, and a third resistor 1670. The third transistor 1630 and the second transistor 1610 are connected in reverse series, and the third transistor 1630 can be a field-effect transistor. For example, the third transistor 1630 can be a JFET, MOSFET, etc. As one implementation, the third transistor 1630 can be the same type as the second transistor 1610, for example, both can be MOSFETs.

[0076] As one implementation method, please refer to Figure 7 The source and drain of the third transistor 1630 are connected to form a common terminal. The common terminal of the third transistor 1630 is connected to the common terminal of the second transistor 1610. The gate of the third transistor 1630 is connected to the second terminal 1414 of the designated resistor 1410. The second resistor 1650 is connected in parallel with the second transistor 1610, and the third resistor 1670 is connected in parallel with the third transistor 1630.

[0077] As another implementation method, please refer to Figure 8The source and drain of the third transistor 1630 are connected to form a common terminal. The common terminal of the third transistor 1630 is connected to the first terminal 1412 of the designated resistor 1410. The gate of the third transistor 1630 is connected to the gate of the second transistor 1610. The second resistor 1650 is connected in parallel with the second transistor 1610, and the third resistor 1670 is connected in parallel with the third transistor 1630.

[0078] Specifically, the resistance value of the second resistor 1650 can be greater than or equal to 10kΩ. For example, the resistance value of the second resistor 1650 can be 10kΩ, 12kΩ, 15kΩ, etc. The resistance value of the third resistor 1670 can be greater than or equal to 10kΩ. For example, the resistance value of the third resistor 1670 can be 10kΩ, 12kΩ, 15kΩ, etc. As one implementation, the resistance values ​​of the second resistor 1650 and the third resistor 1670 can be the same.

[0079] It should be noted that the second resistor 1650 can serve as a self-biasing resistor to provide a bias voltage for the second transistor 1610, and the third resistor 1670 can serve as a self-biasing resistor to provide a bias voltage for the third transistor 1630. Therefore, in this embodiment, the gates of the second transistor 1610 and the third transistor 1630 do not require a bias voltage, which reduces the difficulty of routing the RF switch 100 and makes its structure more compact. Furthermore, since the second transistor 1610 and the third transistor 1630 do not require an additional bias voltage, the situation where the second transistor 1610 and the third transistor 1630 cannot operate smoothly due to external influences on the bias voltage (e.g., interference from RF signals) can be avoided, thus ensuring the normal operation of the adjustable capacitor unit 160.

[0080] Furthermore, since the second resistor 1650 and the second transistor 1610 can be equivalent to an RC phase-shifting circuit, and the third resistor 1670 and the third transistor 1630 can be equivalent to another RC phase-shifting circuit, the adjustable capacitor unit 160 in this embodiment is a two-stage RC phase-shifting circuit, which can reduce the deterioration of the second harmonic, further improve the harmonic suppression effect, and improve the withstand voltage effect in high-power scenarios, so as to ensure the service life of the components in the adjustable capacitor unit 160.

[0081] In some possible embodiments, the element size of the second transistor 1610 is smaller than that of the first transistor 120, which can save layout space of the RF switch 100 and make the overall structure of the RF switch 100 more compact. Specifically, the element size of the second transistor 1610 can be 5% to 15% of the element size of the first transistor 120. For example, if the element size of the first transistor 120 is 1 mm, the element size of the second transistor 1610 is approximately between 0.05 mm and 0.15 mm.

[0082] Here, we take the first transistor 120 as an example, which is a MOSFET, to illustrate the component dimensions.

[0083] In this embodiment, the first transistor 120 may include an active layer (not shown) and a metal layer 1210, wherein the active layer is provided with one or more MOSFETs. Exemplarily, the active layer may be formed by creating two highly doped diffusion regions on a silicon substrate, and then leading out two connection terminals (not shown) respectively, which can serve as the source and drain of the MOSFETs respectively.

[0084] Metal layer 1210 is connected to the active layer and serves as an electrical connection. Please refer to [link / reference]. Figure 9 The metal layer 1210 may include a first comb finger 1212 and a second comb finger 1214, which are spaced apart. The first comb finger 1212 is used to connect one of the two connection terminals, and the second comb finger 1214 is used to connect the other of the two connection terminals. They respectively serve to shunt the current flowing through the first transistor 120 to ensure that the first transistor 120 can work in high current scenarios.

[0085] Specifically, the first comb member 1212 and the second comb member 1214 may each include a plurality of comb electrodes 1216; the plurality of comb electrodes 1216 included in the first comb member 1212 and the plurality of comb electrodes 1216 included in the second comb member 1214 are arranged alternately in a first preset direction X, and the plurality of comb electrodes 1216 included in the same comb member are connected to each other.

[0086] In this embodiment, the element size is the product of the width of the comb-finger electrode 1216 and the number of comb-finger electrodes 1216. Here, the "width of the comb-finger electrode" refers to the size of a single comb-finger electrode 1216 in the second predetermined direction Y, that is, Figure 9The distance D in the figure, and the "number of comb electrodes" refer to the number of comb electrodes included in a single comb element. The second preset direction Y intersects the first preset direction X. In some possible examples, the second preset direction Y and the first preset direction X are perpendicular. For example, if the width of the comb electrode 1216 is 0.1 mm and the number of comb electrodes 1216 is 30, then the element size of the first transistor 120 is 0.1 mm * 30 = 3.0 mm.

[0087] In some possible embodiments, there can be multiple adjustable capacitor units 160 and designated resistors 1410. Multiple adjustable capacitor units 160 and corresponding multiple designated resistors 1410 together constitute multiple RC suppression circuits, which can further improve the suppression effect on harmonic signals.

[0088] In one implementation, the number of adjustable capacitor units 160 and designated resistors 1410 is M, where M is less than or equal to N. For example, when N equals 6, M can be any of 1, 2, 3, 4, 5, or 6. The M designated resistors are the first M resistors of the N first resistors along a first direction X1, where the first direction X1 is the direction from the first connection terminal 102 to the second connection terminal 104. That is, in this embodiment, the M adjustable capacitor units 160 are located on the same side of the RF switch 100. In some possible embodiments, M can be an integer greater than 1. For example, please refer to [link to relevant documentation]. Figure 10 M is set to 2, and there are 2 adjustable capacitor units 160.

[0089] In another implementation, the number of adjustable capacitor units 160 and designated resistors 1410 is K*2, where K*2 is less than or equal to N. For example, when N equals 8, K can be any of 1, 2, 3, or 4. The K*2 designated resistors 1410 may include K first designated resistors 1416 and K second designated resistors 1418. The K first designated resistors 1416 are the first K resistors of the N first resistors 140 along a first direction X1, where the first direction X1 is the direction from the first connection terminal 102 to the second connection terminal 104. The K second designated resistors 1418 are the first K resistors of the N first resistors 140 along a second direction X1, where the second direction X1 is the direction from the second connection terminal 104 to the first connection terminal 102. That is, in this embodiment, the K*2 adjustable capacitor units 160 are distributed on both sides of the RF switch 100. In some possible embodiments, K can be an integer greater than 1. For example, please refer to... Figure 11 K is set to 2, and there are 4 adjustable capacitor units 160.

[0090] In both of the above embodiments, placing the RC phase-shifting circuit at one or both ends of the series branch of the RF switch 100 can further improve the suppression effect on harmonics compared to placing it in the middle of the series branch.

[0091] It should be noted that the RF switch 100 includes multiple adjustable capacitor units 160, and each adjustable capacitor unit 160 is implemented using only a single transistor (i.e., Figure 5 In the embodiment shown, the multiple second transistors 1610 corresponding to the multiple adjustable capacitor units 160 are connected in the same direction. For example, the gate of each second transistor 1610 is connected to the first terminal 1412 of the corresponding designated resistor 1410, and the common terminal 1612 of the second transistor 1610 is connected to the second terminal 1414 of the corresponding designated resistor 1410. Of course, the gate of each second transistor 1610 can also be connected to the second terminal 1414 of the corresponding designated resistor 1410, and the common terminal 1612 of the second transistor 1610 can be connected to the first terminal 1412 of the corresponding designated resistor 1410.

[0092] This application provides a radio frequency switch 100. Since the adjustable capacitor unit 160 and the designated resistor 1410 can jointly form an RC phase-shifting circuit, when a portion of the harmonic signal passes through this RC phase-shifting circuit, the phase of the signal will shift by at least 90 degrees. Ideally, the signal phase can be shifted by 180 degrees after passing through the RC phase-shifting circuit. Therefore, when the phase-shifted portion of the signal is combined with another portion of the harmonic signal that has not been phase-shifted, the two signals can cancel each other out, thereby achieving the suppression of harmonic signals. In summary, the radio frequency switch 100 in this application can achieve the suppression effect of harmonic signals by setting the adjustable capacitor unit 160, thereby ensuring the transmission quality of radio frequency signals.

[0093] Please see Figure 12 The second embodiment of this application also provides a radio frequency switch 300, which may have a first connection terminal 302 and a second connection terminal 304. The radio frequency switch 300 may include N first transistors 320, N first resistors 340, and M adjustable capacitor units 360. The N first transistors 320 are connected in series between the first connection terminal 302 and the second connection terminal 304, where N is an integer greater than 1. The N first resistors 340 are connected in parallel with the N first transistors 320 in a one-to-one correspondence. The M adjustable capacitor units 360 are connected in parallel with M designated resistors 3410 of the N first resistors 340 in a one-direction X1, where M is less than or equal to N, and the first direction X1 is the direction from the first connection terminal 302 to the second connection terminal 304.

[0094] This application provides an RF switch 300, in which each adjustable capacitor unit 360 and its corresponding designated resistor 3410 together constitute an RC phase-shifting circuit. When a portion of the harmonic signal passes through this RC phase-shifting circuit, the phase of the signal shifts by at least 90 degrees. Ideally, the signal phase can be shifted by 180 degrees through the RC phase-shifting circuit. Therefore, when the phase-shifted portion of the signal is combined with another portion of the harmonic signal that has not been phase-shifted, the two signals can cancel each other out, thereby achieving the suppression of the harmonic signal.

[0095] Furthermore, when M is greater than 1, the multiple adjustable capacitor units 360 and the corresponding multiple designated resistors 3410 together constitute multiple RC suppression circuits, which can further improve the suppression effect on harmonic signals. In summary, the RF switch 300 in this embodiment can achieve the suppression effect on harmonic signals by setting M adjustable capacitor units 360, thereby ensuring the transmission quality of RF signals.

[0096] Specifically, the features of the first transistor 320, the first resistor 340, and the adjustable capacitor unit 360 can be referred to and adopted from the features of the first transistor 120, the first resistor 140, and the adjustable capacitor unit 160 in the first embodiment, respectively. To save space, they will not be described in detail here.

[0097] It should be noted that, without conflict, any one or more other features of the RF switch 100 in the first embodiment can be incorporated into the RF switch 300 in the second embodiment. To save space, these will not be elaborated here.

[0098] Please see Figure 13The second embodiment of this application also provides a radio frequency switch 400, which may have a first connection terminal 402 and a second connection terminal 404. The radio frequency switch 400 may include N first transistors 420, N first resistors 440, and K*2 adjustable capacitor units 460. The N first transistors 420 are connected in series between the first connection terminal 402 and the second connection terminal 404, where N is an integer greater than 1. The N first resistors 440 are connected in parallel with the N first transistors 420 in a one-to-one correspondence. The K*2 adjustable capacitor units 460 are connected in parallel with K*2 designated resistors among the N first resistors 440 in a one-to-one correspondence. K*2 is less than or equal to N. The K*2 designated resistors may include K first designated resistors 4416 and K second designated resistors 4418. The K first designated resistors 4416 are the first K resistors of the N first resistors 440 in a first direction X1, where the first direction X1 is the direction from the first connection terminal 402 to the second connection terminal 404. The K second specified resistors 4418 are the first K resistors of the N first resistors 440 in the second direction X1, where the second direction X1 is the direction from the second connection terminal 404 to the first connection terminal 402.

[0099] This application provides an RF switch 400, in which each adjustable capacitor unit 460 and its corresponding designated resistor together constitute an RC phase-shifting circuit. When a portion of the harmonic signal passes through this RC phase-shifting circuit, the phase of the signal will shift by at least 90 degrees. Ideally, the signal phase can be shifted by 180 degrees after passing through the RC phase-shifting circuit. Therefore, when the phase-shifted portion of the signal is combined with another portion of the harmonic signal that has not been phase-shifted, the two signals can cancel each other out, thereby achieving the suppression of the harmonic signal.

[0100] Furthermore, since K*2 is greater than 1, this indicates that the RF switch 400 includes multiple adjustable capacitor units 460. These multiple adjustable capacitor units 460, together with corresponding multiple designated resistors, can form multiple RC suppression circuits to further improve the suppression effect on harmonic signals. In summary, the RF switch 400 in this application can achieve the suppression effect on harmonic signals by setting K*2 adjustable capacitor units 460, thereby ensuring the transmission quality of RF signals.

[0101] Specifically, the features of the first transistor 420, the first resistor 440, and the adjustable capacitor unit 460 can be referred to and adopted from the features of the first transistor 120, the first resistor 140, and the adjustable capacitor unit 160 in the first embodiment, respectively. To save space, they will not be described in detail here.

[0102] It should be noted that, without conflict, any one or more other features of the RF switch 100 in the first embodiment can be incorporated into the RF switch 400 in the third embodiment. To save space, these will not be elaborated here.

[0103] In this application specification, certain terms are used to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. The specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to"; "generally" means that those skilled in the art can solve the technical problem within a certain margin of error and basically achieve the technical effect.

[0104] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "inside", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of simplifying the description of this application and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0105] In this application, unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or merely surface contact. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0106] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0107] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A radio frequency switch, characterized in that, include: N first transistors connected in series, where N is an integer greater than 1; N first resistors are connected in parallel with N first transistors in a one-to-one correspondence; as well as An adjustable capacitor unit is connected in parallel with one of the N first resistors to form a suppression circuit together with the specified resistor. The suppression circuit is used to suppress harmonic signals in the radio frequency signal passing through the radio frequency switch.

2. The radio frequency switch according to claim 1, characterized in that, The adjustable capacitor unit includes a second transistor, which is a field-effect transistor. The gate of the second transistor is connected to the first end of the specified resistor; the source and drain of the second transistor are connected to form a common terminal, and the common terminal of the second transistor is connected to the second end of the specified resistor.

3. The radio frequency switch according to claim 2, characterized in that, The adjustable capacitor unit further includes a third transistor, a second resistor, and a third resistor; the third transistor and the second transistor are connected in series, and the third transistor is a field-effect transistor; The source and drain of the third transistor are connected to form a common terminal, the common terminal of the third transistor is connected to the common terminal of the second transistor, and the gate of the third transistor is connected to the second terminal of the specified resistor. The second resistor and the second transistor are connected in parallel, and the third resistor and the third transistor are connected in parallel.

4. The radio frequency switch according to claim 2, characterized in that, The adjustable capacitor unit further includes a third transistor, a second resistor, and a third resistor; the third transistor and the second transistor are connected in series, and the third transistor is a field-effect transistor; The source and drain of the third transistor are connected to form a common terminal, the common terminal of the third transistor is connected to the first terminal of the specified resistor, and the gate of the third transistor is connected to the gate of the second transistor. The second resistor and the second transistor are connected in parallel, and the third resistor and the third transistor are connected in parallel.

5. The radio frequency switch according to claim 2, characterized in that, The adjustable capacitor unit includes one second transistor, which is connected in parallel across the specified resistor.

6. The radio frequency switch according to claim 2, characterized in that, The adjustable capacitor unit includes multiple second transistors; Multiple second transistors are connected in series and then connected in parallel across the specified resistor; in two adjacent second transistors, the common terminal of one second transistor is connected to the gate of the other second transistor.

7. The radio frequency switch according to claim 3 or 4, characterized in that, The gates of the second transistor and the third transistor are not biased.

8. The radio frequency switch according to claim 3 or 4, characterized in that, The resistance value of the second resistor is greater than or equal to 10. The resistance value of the third resistor is greater than or equal to 10. .

9. The radio frequency switch according to any one of claims 1 to 6, characterized in that, The radio frequency switch is further provided with a first connection terminal and a second connection terminal, and N first transistors are connected in series between the first connection terminal and the second connection terminal; The number of the adjustable capacitor unit and the designated resistor is M, where M is less than or equal to N; the M designated resistors are the first M resistors of the N first resistors in a first direction, where the first direction is the direction from the first connection terminal to the second connection terminal.

10. The radio frequency switch according to any one of claims 1 to 6, characterized in that, The radio frequency switch is further provided with a first connection terminal and a second connection terminal, and N first transistors are connected in series between the first connection terminal and the second connection terminal; The number of the adjustable capacitor unit and the designated resistor is K*2, where K*2 is less than N; the K*2 designated resistors include K first designated resistors and K second designated resistors, where the K first designated resistors are the first K resistors of the N first resistors in a first direction, and the first direction is the direction from the first connection terminal to the second connection terminal; The K second specified resistors are the first K resistors of the N first resistors in the second direction, where the second direction is the direction from the second connection terminal to the first connection terminal.

11. The radio frequency switch according to any one of claims 2 to 6, characterized in that, The component size of the second transistor is smaller than that of the first transistor.

12. The radio frequency switch according to any one of claims 1 to 6, characterized in that, The first transistor is a field-effect transistor; the first resistor is connected between the source and drain of the first transistor; the resistance value of the first resistor is greater than or equal to 10. .

13. The radio frequency switch according to any one of claims 1 to 6, characterized in that, The radio frequency switch is further provided with a first connection terminal and a second connection terminal, and N first transistors are connected in series between the first connection terminal and the second connection terminal to form a series branch. The radio frequency switch also includes a parallel branch, one end of which is connected to one end of the series branch used to connect the tuning element, and the other end of the parallel branch is grounded.

14. A radio frequency switch, characterized in that, The radio frequency switch has a first connection terminal and a second connection terminal, and the radio frequency switch includes: N first transistors are connected in series between the first connection terminal and the second connection terminal; where N is an integer greater than 1. N first resistors are connected in parallel with N first transistors, one-to-one; and M adjustable capacitor units are connected in parallel with M designated resistors out of N first resistors, one-to-one; wherein, the M designated resistors are the first M resistors of the N first resistors in a first direction, M is less than N, and the first direction is the direction from the first connection terminal to the second connection terminal.

15. A radio frequency switch, characterized in that, The radio frequency switch has a first connection terminal and a second connection terminal, and the radio frequency switch includes: N first transistors are connected in series between the first connection terminal and the second connection terminal; where N is an integer greater than 1. N first resistors are connected in parallel with N first transistors, one-to-one; and K*2 adjustable capacitor units are connected in parallel with K*2 designated resistors out of N first resistors, one-to-one; wherein K*2 is less than N; the K*2 designated resistors include K first designated resistors and K second designated resistors, the K first designated resistors are the first K resistors of the N first resistors in a first direction, the first direction being the direction from the first connection terminal to the second connection terminal; the K second designated resistors are the first K resistors of the N first resistors in a second direction, the second direction being the direction from the second connection terminal to the first connection terminal.

16. A radio frequency front-end module, characterized in that, include: The radio frequency switch as described in any one of claims 1 to 15.

17. The radio frequency front-end module according to claim 16, characterized in that, The radio frequency front-end module is provided with an antenna port for connecting an antenna; the radio frequency front-end module includes multiple parallel tuning branches; Each of the tuning branches includes the radio frequency switch and the tuning element, which are connected in series; one end of the tuning branch is connected to the antenna port, and the other end is grounded.

18. The radio frequency front-end module according to claim 16, characterized in that, The radio frequency front-end module is provided with a signal port and an antenna port for connecting an antenna; the radio frequency front-end module includes multiple parallel tuning branches; Each of the tuning branches includes the radio frequency switch and the tuning element, which are connected in series; one end of the tuning branch is connected to the antenna port and the other end is connected to the signal port.

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