CN113595579B

CN113595579B - Radio frequency switch module and radio frequency switch circuit

Info

Publication number: CN113595579B
Application number: CN202110744151.8A
Authority: CN
Inventors: 蓝焕青; 王欢; 奉靖皓; 李海著; 倪建兴
Original assignee: Radrock Shenzhen Technology Co Ltd
Current assignee: Radrock Shenzhen Technology Co Ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2023-03-24
Anticipated expiration: 2041-06-30
Also published as: CN113595579A

Abstract

The invention discloses a radio frequency switch module and a radio frequency switch circuit, wherein the radio frequency switch module comprises a substrate, a radio frequency switch chip arranged on the substrate, an antenna port and a transmission line network; the radio frequency switch chip comprises a radio frequency switch circuit, and the radio frequency switch circuit comprises a first switch unit and a second switch unit; the transmission line network includes a first transmission line coupling the antenna port to a first end of the first switch unit and a second transmission line coupling the antenna port to a first end of the second switch unit, a second end of the first switch unit being connected to the first signal transmission path and a second end of the second switch unit being connected to the second signal transmission path. According to the technical scheme, under the condition that an additional harmonic signal suppression circuit is not required to be added, effective suppression of harmonic signals in the radio frequency switch circuit is achieved, the occupied area of the radio frequency switch circuit is reduced, the complexity of the radio frequency switch circuit is reduced, and the overall performance of the radio frequency switch circuit is improved.

Description

Radio frequency switch module and radio frequency switch circuit

Technical Field

The invention relates to the technical field of radio frequency, in particular to a radio frequency switch module and a radio frequency switch circuit.

Background

In recent years, the wireless communication industry has seen explosive growth. The rf switch circuit is used as a key module in a wireless communication system, and can be used for switching rf signal paths in an rf front-end system, and thus is widely applied to rf front-ends. However, some harmonic signals inevitably exist in the signal transmission path of the radio frequency switch circuit, thereby affecting the performance of the radio frequency switch circuit.

Disclosure of Invention

The embodiment of the invention provides a radio frequency switch module and a radio frequency switch circuit, which aim to solve the problem that harmonic signals in the radio frequency switch circuit cannot be effectively inhibited.

A radio frequency switch module comprises a substrate, a radio frequency switch chip arranged on the substrate, an antenna port and a transmission line network;

the radio frequency switch chip comprises a radio frequency switch circuit, and the radio frequency switch circuit comprises a first switch unit and a second switch unit;

the transmission line network includes a first transmission line coupling the antenna port to a first end of the first switch unit and a second transmission line coupling the antenna port to a first end of the second switch unit, a second end of the first switch unit being connected to the first signal transmission path and a second end of the second switch unit being connected to the second signal transmission path.

Further, the inductance value presented by the first transmission line is in negative correlation with the frequency of the radio-frequency signal transmitted on the second switch unit; the inductance value of the second transmission line is inversely related to the frequency of the radio-frequency signal transmitted on the first switch unit.

Further, the radio frequency switch circuit further comprises a third switch unit; the transmission line network further comprises a third transmission line;

the third transmission line couples the antenna port to a first end of the third switching unit, a second end of the third switching unit being connected to a third signal transmission path.

Further, an inductance value exhibited by the third transmission line is negatively correlated with the frequency of the radio-frequency signal transmitted by the first switch unit, or the inductance value exhibited by the third transmission line is negatively correlated with the frequency of the radio-frequency signal transmitted by the second switch unit.

Furthermore, the radio frequency switch module also comprises a harmonic suppression circuit arranged on the substrate; the harmonic suppression circuit is disposed between the antenna port and the transmission line network, and the harmonic suppression circuit is configured to suppress harmonic signals in the radio frequency switching circuit.

Further, the harmonic suppression circuit includes a first inductance and a first capacitance connected in parallel.

Further, the first capacitor is an adjustable capacitor.

Further, the harmonic suppression circuit includes a first inductor and a first metal line disposed on a first metal layer of a substrate, a first end of the first inductor is connected to a first end of the first metal line, and a second end of the first inductor is connected to a second end of the first metal line;

and a second metal wire is arranged on the metal layer adjacent to the first metal layer, at least part of the projection of the second metal wire and the first metal wire in the longitudinal direction is overlapped, and the second metal wire is connected with a grounding terminal.

A radio frequency switch circuit comprises a selection switch network and an antenna port, wherein the selection switch network comprises a public port, a first selection switch branch and a second selection switch branch, a first end of the first selection switch branch is coupled to the public port, a first end of the second selection switch branch is coupled to the public port, the public port is connected with the antenna port, a second end of the first selection switch branch is connected with a first signal transmission path, and a second end of the second selection switch branch is connected with a second signal transmission path;

the first selection switch branch comprises a first switch unit and a second inductor which are connected in series; the second selection switch branch comprises a second switch unit and a third inductor which are connected in series.

Further, the second inductor is negatively correlated with the frequency of the radio frequency signal transmitted by the second selection switch branch, and the third inductor is negatively correlated with the frequency of the radio frequency signal transmitted by the first selection switch branch.

Further, the radio frequency switch circuit further comprises a harmonic suppression circuit disposed between the selection switch network and the antenna port;

the harmonic suppression circuit comprises a fourth inductor, a second capacitor and a third capacitor;

a first end of the fourth inductor is connected with the antenna port, and a second end of the fourth inductor is connected with the selection switch network;

one end of the second capacitor is coupled to the first end of the fourth inductor, and the other end of the second capacitor is connected with a ground terminal;

one end of the third capacitor is coupled to the second end of the fourth inductor, and the other end of the third capacitor is connected with a ground terminal.

A radio frequency switch circuit comprises a selection switch network and an antenna port, wherein the selection switch network comprises a public port, a fifth inductor, a sixth inductor, a first selection switch branch, a second selection switch branch and a third selection switch branch; a first end of the second selection switch branch is coupled to the common port, a first end of the fifth inductor is coupled to the common port, a first end of the sixth inductor is coupled to the common port, a second end of the fifth inductor is connected to the first end of the first selection switch branch, and a second end of the sixth inductor is connected to the first end of the third selection switch branch;

the second end of the first selection switch branch is connected with a first signal transmission path, the second end of the second selection switch branch is connected with a second signal transmission path, and the second end of the third selection switch branch is connected with a third signal transmission path;

the first selection switch branch comprises a first switch unit, the second selection switch branch comprises a second switch unit, and the third selection switch branch comprises a third switch unit.

The radio frequency switch module comprises a substrate, a radio frequency switch chip arranged on the substrate, an antenna port and a transmission line network; the radio frequency switch chip comprises a radio frequency switch circuit, and the radio frequency switch circuit comprises a first switch unit and a second switch unit; the transmission line network comprises a first transmission line and a second transmission line, the first transmission line couples the antenna port to the first end of the first switch unit, the second transmission line couples the antenna port to the first end of the second switch unit, the second end of the first switch unit is connected with the first signal transmission path, the second end of the second switch unit is connected with the second signal transmission path, and the harmonic signals in the radio frequency switch circuit can be effectively suppressed by utilizing the harmonic suppression circuit which is equivalent to the switch unit in the disconnection state and the transmission line in the radio frequency switch circuit, so that the harmonic signals in the radio frequency switch circuit can be effectively suppressed without additionally accessing the harmonic suppression circuit, the occupied area of the radio frequency switch circuit is reduced, the complexity of the radio frequency switch circuit is reduced, and the overall performance of the radio frequency switch circuit is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments of the present invention will be briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive labor.

FIG. 1 is a circuit diagram of an RF switch module according to an embodiment of the present invention;

FIG. 2 is another circuit diagram of the RF switch module according to an embodiment of the present invention;

FIG. 3 is another circuit diagram of the RF switch module according to an embodiment of the present invention;

FIG. 4 is a schematic circuit diagram of an RF switch module according to an embodiment of the present invention;

FIG. 5 is a circuit diagram of an adjustable capacitor according to an embodiment of the present invention;

FIG. 6 is a schematic circuit diagram of an RF switch module according to an embodiment of the present invention;

FIG. 7 is a circuit diagram of an RF switch circuit according to an embodiment of the present invention;

FIG. 8 is another circuit diagram of the RF switch circuit according to an embodiment of the present invention;

fig. 9 is another circuit diagram of the rf switch circuit according to an embodiment of the invention.

In the figure: 10. a substrate; 20. a radio frequency switch chip; 21. a radio frequency switch circuit 21; 211. a first switch unit; 212. a second switching unit; 213. a third switching unit; 30. an antenna port; 40. a transmission line network; 41. a first transmission line; 42. a second transmission line; 43. a third transmission line; 50. a harmonic suppression circuit; 51. a first metal layer; 52. a first metal line; 53. a second metal line; 60. a selection switch network; 61. a first selection switch branch; 62. a second selection switch branch; 63. and a third selector switch branch.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It is to be understood that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity to indicate like elements throughout.

It will be understood that when an element or layer is referred to as being "on," "adjacent to," "8230303030, adjacent to," "connected to," or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to, or coupled to the other elements or layers, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly adjacent," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatial relationship terms such as "under 82303030," "under 823030; below," "under 823030; above," "over," etc. may be used herein for convenience of description to describe the relationship of one element or feature to another element or feature illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, then elements or features described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "at 8230, below" and "at 8230, below" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and/or "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In the following description, for purposes of explanation, specific details are set forth in order to provide a thorough understanding of the present invention. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.

As shown in fig. 1, the present embodiment provides a radio frequency switch module, which includes a substrate 10, a radio frequency switch chip 20 disposed on the substrate 10, an antenna port 30, and a transmission line network 40; the rf switch chip 20 includes an rf switch circuit 21, and the rf switch circuit 21 includes a first switch unit 211 and a second switch unit 212; the transmission line network 40 includes a first transmission line 41 and a second transmission line 42, the first transmission line 41 couples the antenna port 30 to a first end of the first switching unit 211, the second transmission line 42 couples the antenna port 30 to a first end of the second switching unit 212, a second end of the first switching unit 211 is connected to the first signal transmission path RF1, and a second end of the second switching unit 212 is connected to the second signal transmission path RF2.

The rf switch chip 20 is a chip including an rf switch circuit 21. Wherein, the rf switch circuit 21 can support the transmission of different rf signals. Illustratively, the radio frequency switch circuit 21 may support the transmission of different frequencies, different powers, or other different radio frequency signals. The rf switch circuit 21 may selectively receive an rf input signal in a certain frequency band, or may selectively output an rf amplified signal in a certain frequency band. For example: the rf switch circuit 21 may support transmission of an n77 band rf signal, an n78 band rf signal, or an n79 band rf signal in a 5G high band. Alternatively, the radio frequency switch circuit 21 may also support transmission of a radio frequency signal in a 2G band, a radio frequency signal in a 3G band, a radio frequency signal in a 4G band, or the like.

The transmission line network 40 is a network formed by transmission lines in the rf switch module for connecting the rf switch chip 20 and the antenna port 30. The transmission line network 40 is composed of a number of transmission lines. Alternatively, the number of transmission lines in the transmission line network 40 may be the same as the number of switch units in the radio frequency switch circuit, or the number of transmission lines in the transmission line network 40 may be greater than the number of switch units in the radio frequency switch circuit. Here, the first signal transmission path RF1 and the second signal transmission path RF2 refer to paths for transmitting radio frequency signals. The first signal transmission path RF1 and the second signal transmission path RF2 are two independent signal transmission paths. Preferably, in the present embodiment, the frequency band of the radio frequency signal transmitted by the first signal transmission path RF1 is different from the frequency band of the radio frequency signal transmitted by the second signal transmission path RF2. For example: the first signal transmission path RF1RF is used to transmit radio frequency signals of a first frequency band, and the second signal transmission path RF2 is used to transmit radio frequency signals of a second frequency band. For example: the first frequency band may be an n77 frequency band and the second frequency band may be an n79 frequency band.

As shown in fig. 2, in one embodiment, the rf switch circuit 21 includes a first switch unit 211 and a second switch unit 212. For example, the first switch unit 211 is a first single pole single throw (SPT) switch element S1, and the second switch unit 212 is a second single pole single throw (SPT) switch element S2. The first switch unit 211 and the second switch unit 212 may be rf switches formed by stacking a plurality of transistors, but are not limited thereto, and may be any existing rf switches.

The first switch unit 211 is configured to transmit the radio frequency signal in the first signal transmission path RF1 to the antenna port 30, or transmit the radio frequency signal received by the antenna port 30 to the first signal transmission path RF1. The second switch unit 212 is configured to transmit the radio frequency signal in the second signal transmission path RF2 to the antenna port 30, or transmit the radio frequency signal received by the antenna port 30 to the second signal transmission path RF2.

Specifically, the rf switch module includes a substrate 10, an rf switch chip 20 disposed on the substrate 10, an antenna port 30, and a transmission line network 40. As an example, the transmission line network 40 is used for connecting the antenna port 30 and the rf switch chip 20 to transmit the rf signal received by the antenna port 30 to the rf switch chip 20, or transmit the rf signal output by the rf switch chip 20 to the antenna port 30, so as to implement receiving and transmitting the rf signal.

In a specific embodiment, the rf switch circuit 21 includes a first switch unit 211 and a second switch unit 212, and the rf switch circuit 21 can perform frequency selection on the transmitted rf signal through the first switch unit 211 and the second switch unit 212. As an example, since the first switching unit 211 is connected to the first signal transmission path RF1, the first signal transmission path RF1 is used to transmit a radio frequency signal of a first frequency band; the second switching unit 212 is connected to a second signal transmission path RF2, and the second signal transmission path RF2 is used for transmitting radio frequency signals of a second frequency band. For example: the first frequency band may be an n77 frequency band and the second frequency band may be an n79 frequency band. Therefore, when the radio frequency signal of the first frequency band needs to be transmitted, the first switch unit 211 is turned on, the second switch unit 212 is turned off, and the radio frequency signal of the first frequency band passes through the first signal transmission path RF1 and then is transmitted to the antenna port 30 through the first switch unit 211 and the first transmission line 41, or when the radio frequency signal of the first frequency band needs to be received, the first switch unit 211 is turned on, the second switch unit 212 is turned off, and the radio frequency signal of the first frequency band received by the antenna port 30 passes through the first transmission line 41 and the first switch unit 211 and then is transmitted to the first signal transmission path RF1.

Similarly, when the radio frequency signal of the second frequency band needs to be transmitted, the second switch unit 212 is turned on, the first switch unit 211 is turned off, and the radio frequency signal of the second frequency band passes through the second signal transmission path RF2 and then is transmitted to the antenna port 30 through the second switch unit 212 and the second transmission line 42, or when the radio frequency signal of the second frequency band needs to be received, the second switch unit 212 is turned on, the first switch unit 211 is turned off, and the radio frequency signal of the second frequency band received by the antenna port 30 passes through the second transmission line 42 and the second switch unit 212 and then is transmitted to the second signal transmission path RF2.

Specifically, the transmission line network 40 includes a first transmission line 41 and a second transmission line 42, the first transmission line 41 couples the antenna port 30 to a first end of the first switching unit 211, the second transmission line 42 couples the antenna port 30 to a first end of the second switching unit 212, a second end of the first switching unit 211 is connected to the first signal transmission path RF1, and a second end of the second switching unit 212 is connected to the second signal transmission path RF2.

In a specific embodiment, when the first switch unit 211 is turned on and the second switch unit 212 is turned off, a transmission channel is formed among the antenna port 30, the first transmission line 41, the first switch unit 211 and the first signal transmission path RF1 for transmitting the radio frequency signal of a certain frequency band, and since the second switch unit 212 is in the off state at this time, the second switch unit 212 in the off state can be equivalent to a capacitor to the ground, and the second transmission line 42 can be equivalent to an inductor, therefore, the second switch unit 212 in the off state and the correspondingly connected second transmission line 42 are equivalent to form an LC series resonant circuit, and the LC series resonant circuit can suppress the harmonic signal in the radio frequency switch circuit 21.

Similarly, when the second switch unit 212 is turned on and the first switch unit 211 is turned off, a transmission channel is formed among the antenna port 30, the second transmission line 42, the second switch unit 212 and the second signal transmission path RF2 for transmitting the radio frequency signal of a certain frequency band, and since the first switch unit 211 is in an off state at this time, the first switch unit 211 in the off state can be equivalent to a capacitance to ground, and the first transmission line 41 can be equivalent to an inductance, the first switch unit 211 in the off state and the correspondingly connected first transmission line 41 can be equivalent to form an LC series resonant circuit, and the LC series resonant circuit can suppress the harmonic signal in the radio frequency switch circuit 21.

It should be noted that in the present embodiment, the LC series resonant circuit formed by the first switch unit 211 and the first transmission line 41 in the radio frequency switch circuit 21 in the off state or the LC series resonant circuit formed by the second switch unit 212 and the second transmission line 42 in the off state is used to suppress the harmonic signal in the radio frequency switch circuit 21, and under the condition that no additional harmonic signal suppression circuit is needed, the harmonic signal in the radio frequency switch circuit 21 is effectively suppressed, so as to reduce the occupied area of the radio frequency switch circuit 21 and reduce the complexity of the radio frequency switch circuit 21, and further improve the overall performance of the radio frequency switch circuit 21.

In the present embodiment, the rf switch module includes a substrate 10, an rf switch chip 20 disposed on the substrate 10, an antenna port 30, and a transmission line network 40; the rf switch chip 20 includes an rf switch circuit 21, and the rf switch circuit 21 includes a first switch unit 211 and a second switch unit 212; the transmission line network 40 includes a first transmission line 41 and a second transmission line 42, the first transmission line 41 couples the antenna port 30 to the first end of the first switch unit 211, the second transmission line 42 couples the antenna port 30 to the first end of the second switch unit 212, the second end of the first switch unit 211 is connected to the first signal transmission path RF1, and the second end of the second switch unit 212 is connected to the second signal transmission path RF2, so that the harmonic signals in the radio frequency switch circuit 21 can be effectively suppressed without adding an additional harmonic signal suppression circuit, the occupied area of the radio frequency switch circuit 21 can be reduced, the complexity of the radio frequency switch circuit 21 can be reduced, and the overall performance of the radio frequency switch circuit 21 can be improved.

In one embodiment, the inductance value of the second transmission line 42 is inversely related to the frequency of the rf signal transmitted by the first switch unit 211. Specifically, when the first switch unit 211 is turned on and the second switch unit 212 is turned off, the turned-off second switch unit 212 and the second transmission line 42 form an LC series resonant circuit, which can suppress a harmonic signal doped in the radio frequency signal transmitted through the first switch unit 211.

In an embodiment, when the first switch unit 211 of the rf switch circuit 21 is turned on and the second switch unit 212 is turned off, the capacitance C exhibited by the second switch unit 212 in the off state is fixed, so that the formula is calculated according to the resonant frequency:

wherein. 2fo is the resonant frequency of the harmonic signal to be suppressed by the LC, L is the inductance value exhibited by the second transmission line 42, and C is the capacitance value exhibited by the second switching unit 212 in the off state, the inductance value L exhibited by the second transmission line 42 is inversely related to the resonant frequency 2fo of the harmonic signal to be suppressed, that is, if the resonant frequency 2fo of the harmonic signal to be suppressed is larger, the inductance value L exhibited by the second transmission line 42 is smaller; if the resonant frequency 2fo of the harmonic signal to be suppressed is small, the inductance L exhibited by the second transmission line 42 needs to be large. Since in a specific application the resonance frequency of the harmonic signal is related to the frequency of the radio frequency signal (fundamental signal) transmitted on the first switching unit 211. Such as: if transmitted on the first switch unit 211The frequency of the rf signal is fo, and the harmonic signal to be suppressed is a resonant frequency of 2fo, 3fo or 4fo, etc., so that the inductance value exhibited by the second transmission line 42 is inversely related to the frequency of the rf signal transmitted through the first switch unit 211. When the frequency fo of the rf signal transmitted by the first switch unit 211 is larger, that is, the resonant frequency of the corresponding harmonic signal is also larger than 2fo, 3fo or 4fo, the inductance L exhibited by the second transmission line 42 needs to be smaller. When the frequency fo of the rf signal transmitted by the first switch unit 211 is small, that is, the resonant frequency of the harmonic signal is also small, i.e., 2fo, 3fo or 4fo, the inductance L exhibited by the second transmission line 42 needs to be large.

In a specific embodiment, since the inductance value exhibited by the second transmission line 42 is related to the length of the second transmission line 42, the longer the length of the second transmission line 42 is, the greater the inductance value exhibited by the second transmission line 42 is, so that the length of the second transmission line 42 can be adjusted to suppress the harmonic signal doped in the radio frequency signal transmitted on the first switch unit 211 due to the equivalent resonant circuit of the second switch unit 212 and the second transmission line 42 in the off state. It should be noted that, the suppression of the harmonic signals of any order is also selected according to the actual situation, for example: the resonance point of the resonance circuit equivalent to the second switching unit 212 and the second transmission line 42 in the off state is made to be 2fo to suppress the 2fo harmonic signal.

Likewise, the inductance value of the first transmission line 41 is inversely related to the frequency of the rf signal transmitted by the second switch unit 212. Specifically, when the second switch unit 212 is turned on and the first switch unit 211 is turned off, the turned-off first switch unit 211 and the first transmission line 41 form an LC series resonant circuit, and the LC series resonant circuit can suppress a harmonic signal doped in the radio frequency signal transmitted through the second switch unit 212.

It should be noted that a specific principle that the inductance value of the first transmission line 41 and the frequency of the radio frequency signal transmitted on the second switch unit 212 are in a negative correlation is the same as a specific principle that the inductance value of the second transmission line 42 and the frequency of the radio frequency signal transmitted on the first switch unit 211 are in a negative correlation, and redundant description is omitted here.

In this embodiment, the inductance value of the first transmission line 41 is inversely related to the frequency of the rf signal transmitted by the second switch unit 212; the inductance value presented by the first transmission line 41 is reasonably set to adapt to harmonic suppression of harmonic signals doped with radio-frequency signals of different frequency bands; the inductance value of the second transmission line 42 is inversely related to the frequency of the harmonic signal transmitted by the first switch unit 211, and the inductance value of the second transmission line 42 is reasonably set to adapt to harmonic suppression of the harmonic signal doped with the radio frequency signals of different frequency bands.

As shown in fig. 3, in an embodiment, the rf switch circuit 21 further includes a third switch unit 213; the transmission line network 40 further comprises a third transmission line 43; the third transmission line 43 couples the antenna port 30 to a first end of the third switching unit 213, and a second end of the third switching unit 213 is connected to the third signal transmission path RF 3.

The third switching unit 213 may be a radio frequency switch formed by stacking a plurality of transistors, but is not limited thereto, and may be any existing radio frequency switch. The third signal transmission path RF3 refers to a path for transmitting a radio frequency signal. The third signal transmission path RF3, the first signal transmission path RF1, and the second signal transmission path RF2 are independent transmission paths.

Specifically, the third transmission line 43 couples the antenna port 30 to a first end of the third switching unit 213, a second end of the third switching unit 213 is connected to the third signal transmission path RF3, and a second end of the third switching unit 213 is connected to the third signal transmission path RF3, thereby realizing reception and transmission of radio frequency signals.

In a specific embodiment, when the third switching unit 213 is turned on and the first switching unit 211 and the second switching unit 212 are turned off, a transmission channel is formed among the antenna port 30, the third transmission line 43, the third switching unit 213 and the third signal transmission path RF3 for transmitting the radio frequency signal of a certain frequency band, and since the first switching unit 211 and the second switching unit 212 are in the off state at this time, the first switching unit 211 and the second switching unit 212 in the off state can be equivalent to a capacitance to ground, and the first transmission line 41 and the second transmission line 42 can be equivalent to an inductance, the first switching unit 211 and the correspondingly connected first transmission line 41, and the second switching unit 212 and the correspondingly connected second transmission line 42 in the off state can be equivalent to forming an LC series resonant circuit capable of suppressing the harmonic signal in the radio frequency switching circuit 21.

In a specific embodiment, when the first switch unit 211 is turned on and the second switch unit 212 and the third switch unit 213 are turned off, a transmission channel is formed among the antenna port 30, the first transmission line 41, the first switch unit 211 and the first signal transmission path RF1 for transmitting the RF signal of a certain frequency band, and since the second switch unit 212 and the third switch unit 213 are in the off state at this time, the second switch unit 212 and the third switch unit 213 in the off state may be equivalent to a capacitance to ground, and the second transmission line 42 and the third transmission line 43 may be equivalent to an inductance, the second switch unit 212 and the correspondingly connected second transmission line 42 in the off state, and the third switch unit 213 and the correspondingly connected third transmission line 43 may be equivalent to form an LC series resonant circuit capable of suppressing the harmonic signal in the RF switch circuit 21.

In this embodiment, the rf switch circuit 21 further includes a third switch unit 213; the transmission line network 40 further comprises a third transmission line 43; the third transmission line 43 couples the antenna port 30 to the first end of the third switching unit 213, the second end of the third switching unit 213 is connected to the third signal transmission path RF3, and under the combined action of the first switching unit 211, the second switching unit 212, and the third switching unit 213, not only can the transmission of more radio frequency signals in different frequency bands be supported, but also the harmonic signals in the radio frequency switching circuit 21 can be suppressed by using the series resonant circuit equivalent to the switching unit and the corresponding transmission line in the off state, so as to improve the overall performance of the radio frequency switching circuit 21.

In this embodiment, the inductance value of the third transmission line 43 is negatively related to the frequency of the rf signal transmitted by the first switch unit 211, or the inductance value of the third transmission line 43 is negatively related to the frequency of the rf signal transmitted by the second switch unit 212. The inductance value exhibited by the third transmission line 43 is set reasonably to adapt to harmonic suppression of harmonic signals doped with radio-frequency signals of different frequency bands.

In one embodiment, the inductance value of the third transmission line 43 is inversely related to the frequency of the rf signal transmitted by the first switch unit 211. Specifically, when the first switching unit 211 is turned on and the second switching unit 212 and the third switching unit 213 are turned off, the turned-off second switching unit 212 forms a first LC series resonant circuit with the second transmission line 42, and the turned-off third switching unit 213 forms a second LC series resonant circuit with the third transmission line 43; the first LC series resonant circuit and the second LC series resonant circuit can suppress harmonic signals doped in the radio frequency signal transmitted on the first switching unit 211.

In this embodiment, a specific principle that the inductance value of the third transmission line 43 is negatively related to the frequency of the radio frequency signal transmitted by the first switch unit 211 is the same as a specific principle that the inductance value of the second transmission line 42 is negatively related to the frequency of the radio frequency signal transmitted by the first switch unit 211, and redundant description is omitted here.

In another embodiment, the inductance of the third transmission line 43 is inversely related to the frequency of the rf signal transmitted on the second switch unit 212. Specifically, when the second switching unit 212 is turned on and the first switching unit 211 and the third switching unit 213 are turned off, the turned-off first switching unit 211 forms a first LC series resonant circuit with the first transmission line 41, and the turned-off third switching unit 213 forms a second LC series resonant circuit with the third transmission line 43; the first LC series resonant circuit and the second LC series resonant circuit can suppress harmonic signals doped in the radio frequency signal transmitted on the second switching unit 212.

In this embodiment, the specific principle that the inductance value of the third transmission line 43 is negatively related to the frequency of the radio frequency signal transmitted by the second switch unit 212 is the same as the specific principle that the inductance value of the first transmission line 41 is negatively related to the frequency of the radio frequency signal transmitted by the second switch unit 212, and redundant description is omitted here.

As shown in fig. 4, in an embodiment, the rf switch module further includes a harmonic suppression circuit 50 disposed on the substrate 10; a harmonic rejection circuit 50 is provided between the antenna port 30 and the transmission line network 40, the harmonic rejection circuit 50 being configured to reject harmonic signals in the radio frequency switching circuit 21.

In this embodiment, the harmonic suppression circuit 50 is disposed between the antenna port 30 and the transmission line network 40 to suppress harmonic signals mixed in the radio frequency signals received from the antenna port 30, so as to improve the quality of the radio frequency signals input to the radio frequency switch circuit 21, or suppress harmonic signals mixed in the radio frequency signals transmitted from the signal transmission path, so as to improve the quality of the radio frequency signals transmitted to the antenna port 30, and further improve the overall performance of the radio frequency switch module.

As shown in fig. 4, in an embodiment, the harmonic suppression circuit 50 includes a first inductor L51 and a first capacitor C51 connected in parallel.

In this embodiment, the harmonic suppression circuit 50 includes a first inductor L51 and a first capacitor C51 connected in parallel, where the first inductor L51 and the first capacitor C51 form an LC parallel resonant circuit to suppress a harmonic signal included in the radio frequency signal received from the antenna port 30, so as to improve the quality of the radio frequency signal input to the radio frequency switch circuit 21, or suppress a harmonic signal included in the radio frequency signal transmitted from the signal transmission path, so as to improve the quality of the radio frequency signal transmitted to the antenna port 30, and further improve the overall performance of the radio frequency switch module.

In one embodiment, the first capacitor C51 is an adjustable capacitor.

In a specific embodiment, the harmonic suppression circuit 50 includes a first inductor L51 and a first capacitor C51 connected in parallel, and the first capacitor C51 is set as an adjustable capacitor, so that the resonant frequency point of the harmonic suppression circuit 50 is easily adjusted, harmonic signals with different frequency magnitudes are suppressed, and the flexibility of the harmonic suppression circuit 50 is improved.

As shown in fig. 5, in a specific embodiment, the adjustable capacitor includes a fourth capacitor C54, a fifth capacitor C55, a sixth capacitor C56, a seventh capacitor C57, a first control fet M1, a second control fet M2, and a third control fet M3.

A first end of the fourth capacitor C54 is connected to the antenna port 30, a second end of the fourth capacitor C54 is connected to the transmission line network 40, a source of the first control fet M1 is connected to the first end of the fourth capacitor C54, a drain of the first control fet M1 is connected to the first end of the fifth capacitor C55, a second end of the fifth capacitor C55 is connected to the second end of the fourth capacitor C54, and a gate of the first control fet M1 is not connected and is configured to control the first control fet M1 to be turned on and off, so that the capacitance value of the adjustable capacitor is adjustable. A source electrode of the second control field-effect transistor M2 is connected with a first end of the fifth capacitor C55, a drain electrode of the second control field-effect transistor M2 is connected with a first end of the sixth capacitor C56, a second end of the sixth capacitor C56 is connected with a second end of the fifth capacitor C55, and a gate electrode of the second control field-effect transistor M2 is not connected and configured to control the second control field-effect transistor M2 to be turned on and off; the source of the third control field-effect transistor M3 is connected to the first end of the sixth capacitor C56, the drain is connected to the first end of the seventh capacitor C57, the second end of the seventh capacitor C57 is connected to the second end of the sixth capacitor C56, and the gate of the third control field-effect transistor M3 is not connected and configured to control the third control field-effect transistor M3 to be turned on and off.

In this example, when the first control fet M1 is turned on and the second control fet M2 and the third control fet M3 are turned off, the capacitance value of the adjustable capacitor is equal to the capacitance value of the fourth capacitor C54 and the fifth capacitor C55 connected in parallel; when the first control field effect transistor M1, the second control field effect transistor M2 and the third control field effect transistor M3 are all turned off, the capacitance value of the adjustable capacitor is the capacitance value of the fourth capacitor C54; when the first control field effect transistor M1, the second control field effect transistor M2, and the third control field effect transistor M3 are all turned on, the capacitance value of the adjustable capacitor is the capacitance value of the fourth capacitor C54, the fifth capacitor C55, the sixth capacitor C56, and the seventh capacitor C57 connected in parallel.

In this embodiment, the first capacitor C51 is an adjustable capacitor, so that the resonant frequency point of the harmonic suppression circuit 50 can be adjusted conveniently, harmonic signals with different frequencies can be suppressed, and the flexibility of the harmonic suppression circuit 50 can be improved.

As shown in fig. 6, in an embodiment, the harmonic suppression circuit 50 includes a first inductor L51 and a first metal line 52 disposed on a first metal layer 51 of the substrate 10, a first end of the first inductor L51 is connected to a first end of the first metal line 52, and a second end of the first inductor L51 is connected to a second end of the first metal line 52; a second metal line 53 is provided on a metal layer adjacent to the first metal layer 51, the second metal line 53 at least partially overlapping the first metal line 52 in a projection in the longitudinal direction, the second metal line 53 being connected to ground.

Wherein the substrate 10 comprises at least two metal layers. The first metal line 52 is a metal transmission line disposed on the first metal layer 51. The second metal line 53 is a metal transmission line disposed on a metal layer adjacent to the first metal layer 51. Alternatively, the metal material may be copper, steel, aluminum wire, or the like, for example.

In an embodiment, the harmonic suppression circuit 50 includes a first inductor L51 and a first metal line 52 disposed on a first metal layer 51 of the substrate 10, a first end of the first inductor L51 is connected to a first end of the first metal line 52, and a second end of the first inductor L51 is connected to a second end of the first metal line 52; a second metal line 53 is disposed on a metal layer adjacent to the first metal layer 51, the second metal line 53 is connected to a ground terminal, when a projection of the second metal line 53 and the first metal line 52 in the longitudinal direction at least partially overlap, the first metal line 52 and the second metal line 53 form an equivalent capacitance, the equivalent capacitance and the first inductor L51 form an LC parallel resonant circuit, and a harmonic signal in the radio frequency switch circuit 21 is suppressed. It should be noted that the larger the area of the second metal line 53 at least partially overlapping the projection of the first metal line 52 in the longitudinal direction, the larger the capacitance value of the equivalent capacitance, so that the resonance frequency of the LC parallel resonant circuit can be set by setting the area of the second metal line 53 at least partially overlapping the projection of the first metal line 52 in the longitudinal direction and the inductance value of the first inductance L51.

In the present embodiment, the harmonic suppression circuit 50 includes a first inductor L51 and a first metal line 52 disposed on a first metal layer 51 of the substrate 10, a first end of the first inductor L51 is connected to a first end of the first metal line 52, and a second end of the first inductor L51 is connected to a second end of the first metal line 52; a second metal line 53 is disposed on a metal layer adjacent to the first metal layer 51, a projection of the second metal line 53 and the first metal line 52 in the longitudinal direction at least partially overlaps, the second metal line 53 is connected to a ground terminal, the first metal line 52 and the second metal line 53 form an equivalent capacitor, the equivalent capacitor and the first inductor L51 form an LC parallel resonant circuit, and harmonic signals in the radio frequency switch circuit 21 are effectively suppressed.

As shown in fig. 7, the present embodiment provides a radio frequency switch circuit 21, which includes a selection switch network 60 and an antenna port 30, where the selection switch network 60 includes a common port, a first selection switch branch 61 and a second selection switch branch 62, a first end of the first selection switch branch 61 is coupled to the common port, a first end of the second selection switch branch 62 is coupled to the common port, the common port is connected to the antenna port 30, a second end of the first selection switch branch 61 is connected to a first signal transmission path RF1, and a second end of the selection switch branch is connected to a second signal transmission path RF 2; the first selection switch branch 61 includes a first switch unit 211 and a second inductor connected in series; the first selection switch leg 61 comprises a second switch unit 212 and a third inductance connected in series.

The selection switch network 60 may support transmission of radio frequency signals of different frequency bands, that is, the selection switch network 60 may selectively receive a radio frequency input signal of a certain frequency band, or may selectively output a radio frequency amplified signal of a certain frequency band. For example, the rf switch circuit 21 may support transmission of a 1G band rf signal, a 2G band rf signal, a 3G band rf signal, a 4G band rf signal, a 5G band rf signal, and the like. The first selection switch branch 61 and the second selection switch branch 62 refer to branches for transmitting radio frequency signals. The first selection switch branch 61 and the second selection switch branch 62 are two independent transmission branches. Preferably, in this embodiment, the frequency band of the rf signal transmitted by the first selection switch branch 61 is different from the frequency band of the rf signal transmitted by the second selection switch branch 62. For example: the first selection switch branch 61 is a path for transmitting a radio frequency signal of a first frequency band, and the second selection switch branch 62 is a path for transmitting a radio frequency signal of a second frequency band. For example: the first frequency band may be an n77 frequency band and the second frequency band may be an n79 frequency band.

In a specific embodiment, a first end of the first selection switch branch 61 is coupled to the common port, a first end of the second selection switch branch 62 is coupled to the common port, the common port is connected to the antenna port 30, a second end of the first selection switch branch 61 is connected to the first signal transmission path RF1, a second end of the selection switch branch is connected to the second signal transmission path RF2, the first selection switch branch 61 includes a first switch unit 211 and a second inductor L61 connected in series, and the second selection switch branch 62 includes a second switch unit 212 and a third inductor L62 connected in series. When the first switch unit 211 is turned on and the second switch unit 212 is turned off, a transmission channel is formed among the antenna port 30, the first switch unit 211 and the third inductor L62 for transmitting the radio frequency signal of a certain frequency band, and since the second switch unit 212 in the off state is capacitive, the second switch unit 212 and the third inductor L62 in the off state form an LC series resonant circuit capable of suppressing the harmonic signal in the radio frequency switch circuit 21.

In this embodiment, the radio frequency switch circuit 21 includes a selection switch network 60, the selection switch network 60 includes a common port, a first selection switch branch 61 and a second selection switch branch 62, a first end of the first selection switch branch 61 is coupled to the common port, a first end of the second selection switch branch 62 is coupled to the common port, the common port is connected to the antenna port 30, a second end of the first selection switch branch 61 is connected to the first signal transmission path RF1, and a second end of the selection switch branch is connected to the second signal transmission path RF 2; the first selection switch branch 61 includes a first switch unit 211 and a second inductor connected in series; the first selection switch branch 61 includes a second switch unit 212 and a third inductor connected in series to suppress a harmonic signal included in the radio frequency signal received from the antenna port 30, so as to improve the quality of the radio frequency signal input to the selection switch network 60, or suppress a harmonic signal included in the radio frequency signal transmitted from the selection switch network 60, so as to improve the quality of the radio frequency signal transmitted to the antenna port 30, thereby improving the overall performance of the radio frequency switch circuit 21.

In an embodiment, the second inductor is negatively correlated with the frequency of the rf signal transmitted by the second selection switch branch 62, and the third inductor L62 is negatively correlated with the frequency of the rf signal transmitted by the first selection switch branch 61 and the first switch unit 211.

In an embodiment, the third inductor L62 and the frequency of the rf signal transmitted by the first switch unit 211 of the first selection switch branch 61 are inversely related to each other. Specifically, when the first switch unit 211 is turned on and the second switch unit 212 is turned off, since the capacitance C exhibited by the second switch unit 212 in the off state is fixed, the formula is calculated according to the resonant frequency:

wherein. 2fo is the resonant frequency of the harmonic signal to be suppressed by the LC, L is the inductance value exhibited by the second transmission line 42, and C is the capacitance value exhibited by the second switching unit 212 in the off state, so that the inductance value L of the third inductor L62 is negatively correlated with the resonant frequency 2fo of the harmonic signal to be suppressed, that is, if the resonant frequency 2fo of the harmonic signal to be suppressed is large, the inductance value L exhibited by the third inductor L62 needs to be small, and if the resonant frequency 2fo of the harmonic signal to be suppressed is small, the inductance value L exhibited by the third inductor L62 needs to be large. Since in a specific application the resonance frequency of the harmonic signal is related to the frequency of the radio frequency signal (fundamental signal) transmitted on the first switching unit 211. Such as: if the frequency of the rf signal transmitted by the first switch unit 211 is fo, the harmonic signal to be suppressed has a resonant frequency of 2fo, 3fo, or 4fo, and thus the inductance of the third inductor L62 and the first switch of the first selection switch branch 61 are obtainedThe frequencies of the rf signals transmitted on the off-units 211 are inversely related. When the frequency fo of the rf signal transmitted by the first switch unit 211 is larger, that is, the resonant frequency of the corresponding harmonic signal is also larger than 2fo, 3fo or 4fo, the inductance L of the first selection switch branch 61 needs to be smaller. When the frequency fo of the rf signal transmitted by the first switch unit 211 is small, that is, the resonant frequency of the corresponding harmonic signal is also small, i.e., 2fo, 3fo or 4fo, the inductance L of the first selection switch branch 61 needs to be large.

In this embodiment, the third inductor L62 is inversely related to the frequency of the rf signal transmitted by the first switch unit 211, and the inductance of the third inductor L62 is set reasonably to adapt to harmonic suppression of harmonic signals doped with the rf signals of different frequency bands.

Similarly, the specific principle that the frequency of the radio frequency signal transmitted by the second inductor and the frequency of the radio frequency signal transmitted by the second selection switch branch 62 are in a negative correlation is the same as the specific principle that the frequency of the radio frequency signal transmitted by the third inductor and the frequency of the radio frequency signal transmitted by the first selection switch branch 61 are in a negative correlation, and redundant description is omitted here. The inductance value of the second inductor can be reasonably set to adapt to harmonic suppression of harmonic signals doped with radio-frequency signals of different frequency bands.

As shown in fig. 8, in one embodiment, the rf switch circuit 21 further includes a harmonic rejection circuit 50 disposed between the selection switch network 60 and the antenna port 30; the harmonic suppression circuit 50 includes a fourth inductor L52, a second capacitor C52, and a third capacitor C53; a first end of the fourth inductor L52 is connected to the antenna port 30, and a second end of the fourth inductor L52 is connected to the selection switch network 60; one end of the second capacitor C52 is coupled to the first end of the fourth inductor L52, and the other end of the second capacitor C52 is connected to the ground terminal; one end of the third capacitor C53 is coupled to the second end of the fourth inductor L52, and the other end of the third capacitor C53 is connected to the ground terminal.

In a specific embodiment, the harmonic suppression circuit 50 includes a fourth inductor L52, a second capacitor C52, and a third capacitor C53; a first end of the fourth inductor L52 is connected to the antenna port 30, and a second end of the fourth inductor L52 is connected to the selection switch network 60; one end of the second capacitor C52 is coupled to the first end of the fourth inductor L52, and the other end of the second capacitor C52 is connected to the ground terminal; one end of the third capacitor C53 is coupled to the second end of the fourth inductor L52, the other end of the third capacitor C53 is connected to the ground, the fourth inductor L52, the second capacitor C52 and the third capacitor C53 are equivalent to an LC parallel resonant circuit, so as to suppress harmonic signals included in the radio frequency signals received from the antenna port 30, improve the quality of the radio frequency signals input into the selection switch network 60, or suppress harmonic signals included in the radio frequency signals transmitted from the selection switch network 60, improve the quality of the radio frequency signals transmitted to the antenna port 30, and further improve the overall performance of the radio frequency switch circuit 21.

In the present embodiment, the radio frequency switch circuit 21 further includes a harmonic suppression circuit 50 disposed between the selection switch network 60 and the antenna port 30; the harmonic suppression circuit 50 includes a fourth inductor L52, a second capacitor C52, and a third capacitor C53; a first end of the fourth inductor L52 is connected to the antenna port 30, and a second end of the fourth inductor L52 is connected to the selection switch network 60; one end of the second capacitor C52 is coupled to the first end of the fourth inductor L52, and the other end of the second capacitor C52 is connected to the ground terminal; one end of the third capacitor C53 is coupled to the second end of the fourth inductor L52, the other end of the third capacitor C53 is connected to the ground, and the harmonic suppression circuit 50 can suppress a harmonic signal included in the radio frequency signal received from the antenna port 30, thereby improving the quality of the radio frequency signal input to the selection switch network 60, or suppress a harmonic signal included in the radio frequency signal transmitted from the selection switch network 60, thereby improving the quality of the radio frequency signal transmitted to the antenna port 30, and further improving the overall performance of the radio frequency switch circuit 21.

As shown in fig. 9, the present embodiment provides a radio frequency switch circuit, which includes a selection switch network 60 and an antenna port 30, where the selection switch network 60 includes a common port, a fifth inductor L63, a sixth inductor L64, a first selection switch branch 61, a second selection switch branch 62, and a third selection switch branch; a first end of the second selective switch branch 62 is coupled to the common port, a first end of the fifth inductor L63 is coupled to the common port, a first end of the sixth inductor L64 is coupled to the common port, a second end of the fifth inductor L63 is connected to the first end of the first selective switch branch 61, and a second end of the sixth inductor L64 is connected to the first end of the third selective switch branch; a second end of the first selection switch branch 61 is connected to a first signal transmission path RF1, a second end of the second selection switch branch 62 is connected to a second signal transmission path RF2, and a second end of the third selection switch branch is connected to a third signal transmission path RF 3; the first selection switch branch 61 includes a first switch unit 211, the second selection switch branch 62 includes a second switch unit 212, and the third selection switch branch includes a third switch unit 213.

The selection switch network 60 may support transmission of radio frequency signals of different frequency bands, that is, the selection switch network 60 may selectively receive a radio frequency input signal of a certain frequency band, or may selectively output a radio frequency amplified signal of a certain frequency band. For example, the rf switch circuit 21 may support transmission of a 1G band rf signal, a 2G band rf signal, a 3G band rf signal, a 4G band rf signal, a 5G band rf signal, and the like. The first selection switch branch 61, the second selection switch branch 62 and the third selection switch branch 63 refer to branches for transmitting radio frequency signals. The first selection switch branch 61, the second selection switch branch 62 and the third selection switch branch 63 are three independent transmission branches. Preferably, in this embodiment, the frequency band of the radio frequency signal transmitted by the first selection switch branch 61, the frequency band of the radio frequency signal transmitted by the second selection switch branch 62 and the frequency band of the radio frequency signal transmitted by the first selection switch branch 61 are different. For example: the first selection switch branch 61 is a path for transmitting a radio frequency signal of a first frequency band, the second selection switch branch 62 is a path for transmitting a radio frequency signal of a second frequency band, and the third selection switch branch 63 is a path for transmitting a radio frequency signal of a third frequency band. For example: the first band may be an n77 band, the second band may be an n79 band, and the third band may be an n78 band.

In a specific embodiment, a first terminal of the second selective switch branch 62 is coupled to the common port, a first terminal of the fifth inductor L63 is coupled to the common port, a first terminal of the sixth inductor L64 is coupled to the common port, a second terminal of the fifth inductor L63 is connected to the first terminal of the first selective switch branch 61, and a second terminal of the sixth inductor L64 is connected to the first terminal of the third selective switch branch 63; a second end of the first selection switch branch 61 is connected to a first signal transmission path RF1, a second end of the second selection switch branch 62 is connected to a second signal transmission path RF2, and a second end of the third selection switch branch 63 is connected to a third signal transmission path RF 3; the first selection switch branch 61 includes a first switch unit 211, the second selection switch branch 62 includes a second switch unit 212, and the third selection switch branch includes a third switch unit 213.

As an example, when the third switching unit 213 is turned on and the first and

second switching units

211 and 212 are turned off, the first and

second switching units

211 and 212 in the off state may be equivalent to one capacitance to ground, and thus, the first and

second switching units

211 and 212 in the off state form a resonance circuit with the fifth inductance L63, which is capable of suppressing harmonic signals in the radio frequency switching circuit 21. Calculating formula according to resonance frequency:

wherein. 2fo is the resonant frequency of the harmonic signal to be suppressed by the resonant circuit, L is the inductance presented by the fifth inductor L63, and C is the total capacitance obtained by connecting the capacitor presented by the first switch unit 211 in the off state and the capacitor of the second switch unit 212 in the off state in parallel.

As another example, when the second switching unit 212 is turned on and the first and

third switching units

211 and 213 are turned off, the first and

second switching units

211 and 212 in the off state may be equivalent to a capacitance to ground, and thus the first and fifth inductors L63 and 212 in the off state form a first resonant circuit, and the second and sixth inductors L64 and 212 in the off state form a second resonant circuit, which can suppress harmonic signals in the radio frequency switching circuit 21.

As another example, when the first switching unit 211 is turned on and the second and

third switching units

212 and 213 are turned off, the second and

third switching units

212 and 213 in the off state may be equivalent to a capacitance to ground, and thus, the second and

third switching units

212 and 213 in the off state form a resonance circuit with the sixth inductance L64, which is capable of suppressing harmonic signals in the radio frequency switching circuit 21. Calculating formula according to resonance frequency:

wherein. 2fo is the resonant frequency of the harmonic signal to be suppressed by the resonant circuit, L is the inductance presented by the sixth inductor L64, and C is the total capacitance obtained by connecting the capacitor presented by the second switching unit 212 in the off state and the capacitor of the third switching unit 213 in the off state in parallel.

In this embodiment, under the combined action of the first switch unit 211, the second switch unit 212, and the third switch unit 213, not only can the rf signals of more different frequency bands be supported for transmission, but also the harmonic signals in the rf switch circuit 21 can be suppressed by using the resonant circuit equivalent to the switch unit and the corresponding inductor in the off state, so as to improve the overall performance of the rf switch circuit 21.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein.

Claims

1. A radio frequency switch module is characterized by comprising a substrate, a radio frequency switch chip arranged on the substrate, an antenna port and a transmission line network;

the transmission line network includes a first transmission line coupling the antenna port to a first end of the first switch element and a second transmission line coupling the antenna port to a first end of the second switch element, a second end of the first switch element being connected to a first signal transmission path and a second end of the second switch element being connected to a second signal transmission path;

the first switch unit and the first transmission line which is correspondingly connected form an LC series resonance circuit in the disconnected state, or the second switch unit and the second transmission line which is correspondingly connected form an LC series resonance circuit in the disconnected state.

2. The RF switch module of claim 1, wherein the inductance value exhibited by the first transmission line is inversely related to the frequency of the RF signal transmitted on the second switch unit; the inductance value of the second transmission line is inversely related to the frequency of the radio-frequency signal transmitted on the first switch unit.

3. The rf switch module of claim 1, wherein the rf switch circuit further includes a third switch unit; the transmission line network further comprises a third transmission line;

4. The RF switch module as claimed in claim 3, wherein the third transmission line exhibits an inductance value that is inversely related to the frequency of the RF signal transmitted through the first switch unit, or the third transmission line exhibits an inductance value that is inversely related to the frequency of the RF signal transmitted through the second switch unit.

5. The rf switch module of claim 1, further comprising a harmonic rejection circuit disposed on the substrate; the harmonic suppression circuit is disposed between the antenna port and the transmission line network, and the harmonic suppression circuit is configured to suppress harmonic signals in the radio frequency switching circuit.

6. The radio frequency switch module of claim 5, wherein the harmonic rejection circuit includes a first inductor and a first capacitor connected in parallel.

7. The RF switch module of claim 6, wherein the first capacitor is an adjustable capacitor.

8. The RF switch module of claim 5, wherein the harmonic rejection circuit includes a first inductor and a first metal line disposed on a first metal layer of a substrate, a first end of the first inductor being connected to a first end of the first metal line, a second end of the first inductor being connected to a second end of the first metal line;

and a second metal wire is arranged on the metal layer adjacent to the first metal layer, the second metal wire and the first metal wire are at least partially overlapped in the projection in the longitudinal direction, and the second metal wire is connected with a ground terminal.

9. A radio frequency switch circuit is characterized by comprising a selection switch network and an antenna port, wherein the selection switch network comprises a public port, a first selection switch branch and a second selection switch branch, a first end of the first selection switch branch is coupled to the public port, a first end of the second selection switch branch is coupled to the public port, the public port is connected with the antenna port, a second end of the first selection switch branch is connected with a first signal transmission path, and a second end of the second selection switch branch is connected with a second signal transmission path;

the first selection switch branch comprises a first switch unit and a second inductor which are connected in series; the second selection switch branch comprises a second switch unit and a third inductor which are connected in series;

the first switch unit and the second inductor which is correspondingly connected form an LC series resonance circuit in the off state, or the second switch unit and the third inductor which is correspondingly connected form an LC series resonance circuit in the off state.

10. The radio frequency switch circuit of claim 9, wherein the second inductance is inversely related to a frequency of the radio frequency signal transmitted on the second selector switch leg, and the third inductance is inversely related to a frequency of the radio frequency signal transmitted on the first selector switch leg.

11. The radio frequency switching circuit of claim 9, further comprising a harmonic rejection circuit disposed between the selection switch network and the antenna port;

12. A radio frequency switch circuit is characterized by comprising a selection switch network and an antenna port, wherein the selection switch network comprises a public port, a fifth inductor, a sixth inductor, a first selection switch branch, a second selection switch branch and a third selection switch branch; a first end of the second selection switch branch is coupled to the common port, a first end of the fifth inductor is coupled to the common port, a first end of the sixth inductor is coupled to the common port, a second end of the fifth inductor is connected to the first end of the first selection switch branch, and a second end of the sixth inductor is connected to the first end of the third selection switch branch;

the first selection switch branch comprises a first switch unit, the second selection switch branch comprises a second switch unit, and the third selection switch branch comprises a third switch unit;

when the first switching unit is turned on and the second switching unit and the third switching unit are turned off, the second switching unit, the third switching unit and the sixth inductor form a resonant circuit;

when the second switching unit is turned on and the first switching unit and the third switching unit are turned off, the first switching unit and the fifth inductor form a first resonant circuit, and the third switching unit and the sixth inductor form a second resonant circuit;

when the third switching unit is turned on and the first switching unit and the second switching unit are turned off, the first switching unit, the second switching unit and the fifth inductor form a resonant circuit.