RF switch circuit and RF front-end module

Abstract

This application discloses a radio frequency (RF) switch circuit and an RF front-end module. The RF switch circuit includes N transistors and at least one first protection module. The N transistors are connected in series between a signal port and a ground port. The first protection module includes a first protection unit and a second protection unit. The positive terminal of the first protection unit is connected to the positive terminal of the second protection unit to form a common node of the first protection module. The common node is connected to the body terminal of the i-th transistor. When the common node of the first protection module is connected to the body terminal of any one of the transistors from the 2nd to the (N-1)th transistor, the negative terminal of the first protection unit is connected to the gate of the m-th transistor, and the negative terminal of the second protection unit is connected to the gate of the n-th transistor. This application can improve the electrostatic discharge capability of the RF switch circuit, ensuring that the RF switch circuit has more reliable electrostatic discharge performance.

Description

Technical Field

[0001] This application relates to the field of radio frequency technology, and more specifically, to a radio frequency switching circuit 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, filtering, etc.) to complete the tasks of receiving and transmitting RF signals.

[0003] In the RF front-end module, the RF switching circuit is an important component. It is 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.

[0004] However, existing RF switching circuits suffer from poor electrostatic discharge capability. Summary of the Invention

[0005] This application provides an embodiment of a radio frequency switch circuit 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 circuit. The RF switch circuit has a signal port and a ground port, and includes N transistors and at least one first protection module. The N transistors are connected in series between the signal port and the ground port, and the transistors are field-effect transistors (FETs). The at least one first protection module is used for conducting static electricity. The first protection module includes a first protection unit and a second protection unit. The positive terminal of the first protection unit is connected to the positive terminal of the second protection unit to form a common node of the first protection module. When there is only one first protection module, the common node of the first protection module is connected to the body terminal of the i-th transistor in a specified direction; when there are multiple first protection modules, the common nodes of the multiple first protection modules are connected one-to-one to the body terminals of the multiple transistors; wherein, the specified direction is the direction from the signal port to the ground port.

[0007] When the common node of the first protection module is connected to the body of the first transistor, the negative terminal of the second protection unit is connected to the gate of the p-th transistor, and the negative terminal of the first protection unit is connected to the negative terminal of the second protection unit or the negative terminal of the first protection unit is left floating; where p is not 1. When the common node of the first protection module is connected to the body of any one of the second to (N-1)-th transistors, the negative terminal of the first protection unit is connected to the gate of the m-th transistor, and the negative terminal of the second protection unit is connected to the gate of the n-th transistor; where m is greater than or equal to 1 and less than i, and n is greater than i and less than or equal to N. When the common node of the first protection module is connected to the body of the N-th transistor, the negative terminal of the first protection unit is connected to the gate of the q-th transistor, and the negative terminal of the second protection unit is connected to the negative terminal of the first protection unit or the negative terminal of the second protection unit is left floating; where q is not N.

[0008] This application provides a radio frequency (RF) switch circuit, which includes N transistors connected in series between a signal port and a ground port, and at least one first protection module for conducting static electricity. The first protection module includes a first protection unit and a second protection unit. The positive terminal of the first protection unit is connected to the positive terminal of the second protection unit to form a common node, and the common node is connected to the body terminal of the i-th transistor. The negative terminals of the first and second protection units are respectively connected to the gates of other transistors.

[0009] In one aspect, this application connects the body of the i-th transistor and the gate of the n-th transistor through a second protection unit, where i is greater than 1 and less than N, and n is greater than i and less than or equal to N; or, it connects the body of the 1-th transistor and the gate of the p-th transistor through a second protection unit, where p is not 1. When the signal port is subjected to electrostatic discharge, the positive voltage static electricity will be quickly conducted through the second protection unit to the gate of the transistor closer to the ground port, enabling the transistor to conduct faster and thus conduct the static electricity to the ground port more efficiently. This accelerates the electrostatic discharge speed of the RF switching circuit, improves the electrostatic discharge capability of the RF switching circuit, and ensures that the RF switching circuit has more reliable electrostatic discharge (ESD) performance.

[0010] On the other hand, this application connects the body of the i-th transistor and the gate of the m-th transistor through a first protection unit, where i is greater than 1 and less than N, and m is greater than or equal to 1 and less than i; or, connects the body of the N-th transistor and the gate of the q-th transistor through a first protection unit, where q is not N. When the signal port is subjected to electrostatic discharge, the negative voltage static electricity will be quickly conducted through the first protection unit to the gate of the transistor closer to the signal port, enabling the transistor to conduct faster, thereby more efficiently conducting static electricity to the ground port, accelerating the electrostatic discharge speed of the RF switching circuit, improving the electrostatic discharge capability of the RF switching circuit, and ensuring that the RF switching circuit has more reliable ESD performance.

[0011] Furthermore, in this application, the positive terminals of the first protection unit and the second protection unit are connected to the body of the transistor, and the negative terminals of the first protection unit and the second protection unit are connected to the gate of the transistor. Taking the first protection unit as an example, when the RF switch circuit is in normal operation, because the DC voltage of the body of the transistor connected to the first protection unit is less than the DC voltage of the gate of the transistor connected to the first protection unit, when a control voltage is applied to the gate of the transistor, due to the unidirectional conductivity of the first protection unit, the control voltage cannot trigger the first protection unit to conduct, thus avoiding the situation where the first protection unit divides the control voltage, and ensuring the normal operation of the RF switch circuit. Similarly, for the second protection unit, the control voltage applied to the gate of the transistor also cannot trigger the second protection unit to conduct, thus ensuring the normal operation of the RF switch circuit.

[0012] According to a second aspect of this application, embodiments of this application also provide a radio frequency (RF) switch circuit. The RF switch circuit includes a signal port and a ground port, and comprises N transistors and a second protection module. The N transistors are connected in series between the signal port and the ground port, and the transistors are field-effect transistors (FETs). The second protection module is used to conduct positive voltage static electricity. The second protection module includes a third protection unit, the positive terminal of which is connected to the body of the first transistor; the negative terminal of the third protection unit is connected to the gate of the p-th transistor; wherein the first transistor is the transistor closest to the signal port among the N transistors, and p is not 1.

[0013] This application provides a radio frequency (RF) switch circuit, which includes N transistors connected in series between a signal port and a ground port, and a second protection module for conducting positive electrostatic discharge (ESD). The body of the first transistor and the gate of the p-th transistor are connected via a third protection unit. When the signal port is subjected to ESD, the positive ESD is rapidly conducted through the third protection unit to the gate of the transistor closer to the ground port (i.e., the p-th transistor), enabling the transistor to conduct more quickly and efficiently to the ground port. This accelerates the ESD discharge speed and improves the ESD discharge capability of the RF switch circuit, ensuring more reliable ESD performance.

[0014] Furthermore, in this application, the positive terminal of the third protection unit is connected to the body terminal of the transistor, and the negative terminal of the third protection unit is connected to the gate terminal of the transistor. When the RF switch circuit is in normal operation, since the DC voltage of the body terminal of the transistor connected to the third protection unit is less than the DC voltage of the gate terminal of the transistor connected to the third protection unit, when a control voltage is applied to the gate terminal of the transistor, due to the unidirectional conductivity of the third protection unit, the control voltage cannot trigger the third protection unit to conduct, thus avoiding the situation where the third protection unit divides the control voltage, thereby ensuring the normal operation of the RF switch circuit.

[0015] According to a third aspect of this application, embodiments of this application also provide a radio frequency (RF) switch circuit. The RF switch circuit includes a signal port and a ground port, and comprises N transistors and a third protection module. The N transistors are connected in series between the signal port and the ground port, and the transistors are field-effect transistors (FETs). The third protection module is used to conduct negative voltage static electricity. The third protection module includes a fourth protection unit, the positive terminal of which is connected to the body of the Nth transistor; the negative terminal of the fourth protection unit is connected to the gate of the qth transistor; wherein the Nth transistor is the transistor closest to the ground port among the N transistors, and q is not N.

[0016] This application provides a radio frequency (RF) switch circuit, which includes N transistors connected in series between a signal port and a ground port, and a third protection module for conducting negative electrostatic discharge (ESD). The body of the Nth transistor and the gate of the qth transistor are connected via a fourth protection unit. When the signal port is subjected to ESD, the negative ESD is rapidly conducted through the fourth protection unit to the gate of the transistor closer to the signal port (i.e., the qth transistor), enabling the transistor to conduct more quickly and efficiently to the ground port. This accelerates the ESD discharge speed and improves the ESD discharge capability of the RF switch circuit, ensuring more reliable ESD performance.

[0017] Furthermore, in this application, the positive terminal of the fourth protection unit is connected to the body terminal of the transistor, and the negative terminal of the fourth protection unit is connected to the gate terminal of the transistor. When the RF switch circuit is in normal operation, since the DC voltage of the body terminal of the transistor connected to the fourth protection unit is less than the DC voltage of the gate terminal of the transistor connected to the fourth protection unit, when a control voltage is applied to the gate terminal of the transistor, due to the unidirectional conductivity of the fourth protection unit, the control voltage cannot trigger the fourth protection unit to conduct, thus avoiding the situation where the fourth protection unit divides the control voltage, and ensuring the normal operation of the RF switch circuit.

[0018] According to a fourth aspect of this application, embodiments of this application also provide a radio frequency (RF) switch circuit. The RF switch circuit includes a signal port and a ground port, comprising N transistors and at least one first protection module. The N transistors are connected in series between the signal port and the ground port, and the transistors are bipolar transistors. The at least one first protection module is used for conducting static electricity. The first protection module includes a first protection unit and a second protection unit, with the positive terminal of the first protection unit connected to the positive terminal of the second protection unit to form a common node of the first protection module. When there is only one first protection module, the common node of the first protection module is connected to the body terminal of the i-th transistor in a specified direction; when there are multiple first protection modules, the common nodes of the multiple first protection modules are connected one-to-one to the body terminals of the multiple transistors; wherein, the specified direction is the direction from the signal port to the ground port.

[0019] When the common node of the first protection module is connected to the body of the first transistor, the negative terminal of the second protection unit is connected to the base of the p-th transistor, and the negative terminal of the first protection unit is connected to the negative terminal of the second protection unit or the negative terminal of the first protection unit is left floating; where p is not 1. When the common node of the first protection module is connected to the body of any one of the second to (N-1)-th transistors, the negative terminal of the first protection unit is connected to the base of the m-th transistor, and the negative terminal of the second protection unit is connected to the base of the n-th transistor; where m is greater than or equal to 1 and less than i, and n is greater than i and less than or equal to N. When the common node of the first protection module is connected to the body of the N-th transistor, the negative terminal of the first protection unit is connected to the base of the q-th transistor, and the negative terminal of the second protection unit is connected to the negative terminal of the first protection unit or the negative terminal of the second protection unit is left floating; where q is not N.

[0020] This application provides a radio frequency (RF) switch circuit, which includes N transistors connected in series between a signal port and a ground port, and at least one first protection module for conducting static electricity. The first protection module includes a first protection unit and a second protection unit. The positive terminal of the first protection unit is connected to the positive terminal of the second protection unit to form a common node, and the common node is connected to the body terminal of the i-th transistor. The negative terminals of the first and second protection units are respectively connected to the bases of other transistors.

[0021] In one aspect, this application connects the body of the i-th transistor and the base of the n-th transistor through a second protection unit, where i is greater than 1 and less than N, and n is greater than i and less than or equal to N; or, it connects the body of the 1-th transistor and the base of the p-th transistor through a second protection unit, where p is not 1. When the signal port is subjected to electrostatic discharge, the positive voltage static electricity will be quickly conducted through the second protection unit to the base of the transistor closer to the ground port, enabling the transistor to conduct faster and thus conduct the static electricity to the ground port more efficiently. This accelerates the electrostatic discharge speed of the RF switching circuit, improves the electrostatic discharge capability of the RF switching circuit, and ensures that the RF switching circuit has more reliable ESD performance.

[0022] On the other hand, this application connects the body of the i-th transistor and the base of the m-th transistor through a first protection unit, where i is greater than 1 and less than N, and m is greater than or equal to 1 and less than i; or, connects the body of the N-th transistor and the base of the q-th transistor through a first protection unit, where q is not N. When the signal port is subjected to electrostatic discharge, the negative voltage static electricity will be quickly conducted through the first protection unit to the base of the transistor closer to the signal port, enabling the transistor to conduct faster and thus more efficiently conduct static electricity to the ground port, thereby accelerating the electrostatic discharge speed of the RF switching circuit, improving the electrostatic discharge capability of the RF switching circuit, and ensuring that the RF switching circuit has more reliable ESD performance.

[0023] Furthermore, in this application, the positive terminals of the first protection unit and the second protection unit are connected to the body of the transistor, and the negative terminals of the first protection unit and the second protection unit are connected to the base of the transistor. Taking the first protection unit as an example, when the RF switch circuit is in normal operation, since the DC voltage of the body of the transistor connected to the first protection unit is less than the DC voltage of the base of the transistor connected to the first protection unit, when a control voltage is applied to the base of the transistor, due to the unidirectional conductivity of the first protection unit, the control voltage cannot trigger the first and second protection units to conduct, thus avoiding the situation where the first protection unit divides the control voltage, and ensuring the normal operation of the RF switch circuit. Similarly, for the second protection unit, the control voltage applied to the base of the transistor also cannot trigger the second protection unit to conduct, ensuring the normal operation of the RF switch circuit.

[0024] According to a fifth aspect of this application, embodiments of this application also provide a radio frequency front-end module, which includes the radio frequency switching circuit described above. Attached Figure Description

[0025] 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.

[0026] Figure 1 This is a schematic diagram of the first circuit structure of the radio frequency switch circuit provided in the embodiments of this application.

[0027] Figure 2 This is a schematic diagram of the second circuit structure of the radio frequency switch circuit provided in the embodiments of this application.

[0028] Figure 3 This is a schematic diagram of the third circuit structure of the radio frequency switch circuit provided in the embodiments of this application.

[0029] Figure 4 This is a simulation diagram provided in the embodiments of this application.

[0030] Figure 5 yes Figure 1 The diagram shows a structural schematic of the first protection module in the radio frequency switch circuit shown.

[0031] Figure 6 yes Figure 1 The diagram shows another structural schematic of the first protection module in the RF switch circuit shown.

[0032] Figure 7This is a schematic diagram of the fourth circuit structure of the radio frequency switch circuit provided in the embodiments of this application.

[0033] Figure 8 yes Figure 7 The diagram shows the structure of the third protection unit in the radio frequency switch circuit.

[0034] Figure 9 This is a schematic diagram of the fifth circuit structure of the radio frequency switch circuit provided in the embodiments of this application.

[0035] Figure 10 yes Figure 9 The diagram shows the structure of the fourth protection unit in the radio frequency switch circuit.

[0036] Figure 11 This is a schematic diagram of the fifth circuit structure of the radio frequency switch circuit provided in the embodiments of this application.

[0037] Figure 12 This is a structural block diagram of the radio frequency front-end module provided in the embodiments of this application. Detailed Implementation

[0038] 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.

[0039] This application provides a radio frequency switch circuit 100, which is an electronic circuit used to control the conduction or disconnection of the transmission path of radio frequency signals. It can be a single-pole single-throw switch circuit, a single-pole double-throw switch circuit, a multi-pole multi-throw switch circuit, etc. This embodiment does not make specific limitations.

[0040] Please see Figure 1 The RF switch circuit 100 includes a signal port 12 and a ground port 14. The signal port 12 is used to transmit RF signals and can be either an input or output port for the RF signal. Furthermore, the signal port 12 can be any node on the RF signal transmission path, such as a node on the connection path between any two adjacent switching transistors. The ground port 14 is used for grounding. The RF switch circuit 100 may include N transistors 20 and at least one first protection module 30, where N is an integer greater than 1; for example, N can be 4, 6, 7, 8, 9, etc. Specifically... Figure 1 In this case, N is 9.

[0041] In at least one embodiment, transistor 20 is a switching transistor. By controlling the voltage or current signal at the control terminal of the switching transistor, its conduction and cutoff are controlled, thereby realizing the "on" and "off" of the radio frequency switching circuit 100, and thus completing functions such as signal path switching, enable control, power supply on / off, and mode switching.

[0042] In this embodiment, N transistors 20 are connected in series between the signal port 12 and the ground port 14, forming a ground path between the signal port 12 and the ground port 14. The transistors 20 are field-effect transistors, such as metal-oxide-semiconductor field-effect transistors (MOSFETs), metal-semiconductor field-effect transistors (MESFETs), etc.

[0043] It should be noted here that "sequentially connected in series" means that in two adjacent transistors 20, the source of one transistor 20 is connected to the drain of the other transistor 20. Furthermore, Figure 1 The circuit structure shown is only a partial circuit structure of the RF switch circuit 100, which forms the grounding path (parallel path) of the RF switch circuit 100. The RF switch circuit 100 may also include an RF signal transmission path, that is, a series path (not shown in the figure). Specifically, there are multiple signal ports 12, which may include signal input ports and signal output ports. The RF switch circuit 100 may also include multiple switching transistors (not shown in the figure), which are connected in series between the signal input ports and the signal output ports to form the aforementioned RF signal transmission path. This embodiment does not specifically limit this aspect.

[0044] In related technologies, when signal port 12 is subjected to electrostatic discharge, the electrostatic voltage will sequentially trigger each transistor 20 to conduct through the parasitic capacitance of the transistor 20 itself (e.g., the parasitic capacitance between the gate and source), thereby allowing the electrostatic discharge to be discharged through ground port 14. However, when the electrostatic voltage passes through the parasitic capacitance, a large voltage drop is required, making it difficult for the transistor 20 to conduct quickly, resulting in poor electrostatic discharge capability.

[0045] To improve the electrostatic discharge capability of the radio frequency switch circuit 100, the inventors of this application provide at least one first protection module 30 on the grounding path formed by N transistors 20. The first protection module 30 is used to conduct electrostatic discharge. The first protection module 30 may include a first protection unit 320 and a second protection unit 340. In this embodiment, both the first protection unit 320 and the second protection unit 340 have unidirectional conductivity. Taking the first protection unit 320 as an example, current can flow smoothly from the positive terminal to the negative terminal; however, when flowing from the negative terminal to the positive terminal, the first protection unit 320 exhibits a high-resistance state. Specifically, the positive terminal of the first protection unit 320 is connected to the positive terminal of the second protection unit 340 to form a common node K of the first protection module 30.

[0046] As an example, when there is only one first protection module 30, the common node K of the first protection module 30 is connected to the body electrode of the i-th transistor 20 in a specified direction H. Here, the specified direction H is the direction from signal port 12 to ground port 14; i is an integer greater than or equal to 1 and less than or equal to N. That is, when there is only one first protection module 30, the common node K of the first protection module 30 can be connected to the body electrode of any transistor 20.

[0047] As another example, when there are multiple first protection modules 30, the common node K of the multiple first protection modules 30 is connected to the body electrode of the multiple transistors 20 in a one-to-one correspondence. That is, when there are multiple first protection modules 30, the common node K of different first protection modules 30 is connected to the body electrode of different transistors 20 respectively.

[0048] Please see Figure 2 When the common node K of the first protection module 30 is connected to the body of the first transistor 20 (i.e., i equals 1), the negative terminal of the second protection unit 340 is connected to the gate of the p-th transistor 20, where p is not 1. For example, p can be 2, 3, ..., N-1, N, etc.

[0049] As an example, such as Figure 2 As shown in region (a), the negative terminal of the first protection unit 320 is connected to the negative terminal of the second protection unit 340. In this case, the first protection unit 320 and the second protection unit 340 are connected in parallel. As another example, as... Figure 2 As shown in region (b), the negative terminal of the first protection unit 320 is left floating. At this time, the negative terminal of the first protection unit 320 is not connected to any component or any port (e.g., ground port), and the first protection unit 320 does not function in the RF switch circuit 100.

[0050] Please refer to it again. Figure 1When the common node K of the first protection module 30 is connected to the body of any one of the transistors 20 from the second to the (N-1)th transistors 20 (i.e., i is greater than 1 and less than N), the negative terminal of the first protection unit 320 is connected to the gate of the m-th transistor 20, and the negative terminal of the second protection unit 340 is connected to the gate of the n-th transistor 20. Here, m is greater than or equal to 1 and less than i, and n is greater than i and less than or equal to N. In this case, the negative terminal of the first protection unit 320 is connected to the gate of the transistor 20 connected between the signal port 12 and the i-th transistor 20, and the negative terminal of the second protection unit 340 is connected to the gate of the transistor 20 connected between the i-th transistor 20 and the ground port 14.

[0051] Please see Figure 3 When the common node K of the first protection module 30 is connected to the body of the Nth transistor 20 (i.e., i equals N), the negative terminal of the first protection unit 320 is connected to the gate of the qth transistor 20, where q is not N. For example, q can be 1, 2, ..., N-2, N-1, etc.

[0052] As an example, such as Figure 3 As shown in region (a), the negative terminal of the second protection unit 340 is connected to the negative terminal of the first protection unit 320. In this case, the first protection unit 320 and the second protection unit 340 are connected in parallel. As another example, as... Figure 3 As shown in region (b), the negative terminal of the second protection unit 340 is left floating. At this time, the negative terminal of the second protection unit 340 is not connected to any component or any port (e.g., ground port), and the second protection unit 340 does not function in the RF switch circuit 100.

[0053] On the one hand, this embodiment will Figure 1 The body of the i-th transistor 20 and the gate of the n-th transistor 20 are connected by a second protection unit 340, wherein i is greater than 1 and less than N, and n is greater than i and less than or equal to N; or, the ... Figure 2The body of the first transistor 20 and the gate of the p-th transistor 20 are connected by a second protection unit 340, where p is not 1. When the signal port 12 is subjected to electrostatic discharge, the positive static electricity will be quickly conducted through the second protection unit 340 to the gate of the transistor 20 (e.g., the n-th transistor 20, the p-th transistor 20) closer to the ground port 14, so that the transistor 20 can turn on faster, and thus conduct the static electricity to the ground port 14 more efficiently, thereby accelerating the electrostatic discharge speed of the RF switch circuit 100, improving the electrostatic discharge capability of the RF switch circuit 100, and ensuring that the RF switch circuit 100 has more reliable electrostatic discharge (ESD) performance.

[0054] On the other hand, this embodiment will Figure 1 The body of the i-th transistor 20 and the gate of the m-th transistor 20 are connected through a first protection unit 320, where i is greater than 1 and less than N, and m is greater than or equal to 1 and less than i; or, the body of the i-th transistor 20 and the gate of the m-th transistor 20 are connected through a first protection unit 320, where i is greater than 1 and less than N, and m is greater than or equal to 1 and less than i; Figure 3 The body of the Nth transistor 20 and the gate of the qth transistor 20 are connected through the first protection unit 320, where q is not N. When the signal port 12 is subjected to electrostatic discharge, the negative voltage static electricity will be quickly conducted through the first protection unit 320 to the gate of the transistor 20 closer to the signal port 12 (e.g., the mth transistor 20, the qth transistor 20), so that the transistor 20 can be turned on faster, and thus conduct the static electricity to the ground port 14 more efficiently, thereby accelerating the electrostatic discharge speed of the RF switch circuit 100, improving the electrostatic discharge capability of the RF switch circuit 100, and ensuring that the RF switch circuit 100 has more reliable ESD performance.

[0055] Therefore, by setting the first protection module 30, this embodiment can conduct static electricity to the gate of the corresponding transistor 20 more quickly, so that the transistor 20 can turn on faster, thereby improving the instantaneous discharge speed of static electricity and improving the ESD performance of the RF switch circuit 100.

[0056] Furthermore, in this embodiment, the positive terminals of the first protection unit 320 and the second protection unit 340 are connected to the body of the transistor 20, and the negative terminals of the first protection unit 320 and the second protection unit 340 are connected to the gate of the transistor 20. Taking the first protection unit 320 as an example, when the RF switch circuit 100 is in normal operation, since the DC voltage of the body of the transistor 20 connected to the first protection unit 320 is less than the DC voltage of the gate of the transistor 20 connected to the first protection unit 320, when a control voltage is applied to the gate of the transistor 20, due to the unidirectional conductivity of the first protection unit 320, the control voltage cannot trigger the first protection unit 320 to conduct, thus avoiding the situation where the first protection unit 320 divides the control voltage, ensuring the normal operation of the RF switch circuit 100. Similarly, for the second protection unit 340, the control voltage applied to the gate of the transistor 20 also cannot trigger the second protection unit 340 to conduct, ensuring the normal operation of the RF switch circuit 100.

[0057] In other words, when the N transistors 20 are in the conducting state under the applied control voltage, the first protection unit 320 and the second protection unit 340 are in a high-impedance state, and the first protection unit 320 and the second protection unit 340 will not be mis-conducted, ensuring that the grounding path of the RF switch circuit 100 can work smoothly.

[0058] The specific implementation of the first protection module 30 is explained below.

[0059] In this embodiment, as Figure 2 As shown, when the common node K of the first protection module 30 is connected to the body electrode of the first transistor 20, the second protection unit 340 is used to conduct positive voltage static electricity. Further, in Figure 2 In region (a), when the negative terminal of the first protection unit 320 is connected to the negative terminal of the second protection unit 340, the first protection unit 320 and the second protection unit 340 are used together to conduct positive voltage static electricity. Specifically, when one of the first protection unit 320 and the second protection unit 340 is damaged (e.g., open circuit), the other can still conduct positive voltage static electricity, thereby improving the operational reliability of the first protection module 30.

[0060] like Figure 1As shown, when the common node K of the first protection module 30 is connected to the body electrode of any one of the second to (N-1)th transistors 20, the first protection unit 320 is used to conduct negative electrostatic discharge (ESD), and the second protection unit 340 is used to conduct positive ESD. Therefore, in this embodiment, the first protection module 30 can conduct both positive and negative ESD, providing more comprehensive ESD protection to the RF switch circuit 100. Here, "positive ESD" refers to positively charged ESD with a corresponding voltage greater than 0V; "negative ESD" refers to negatively charged ESD with a corresponding voltage less than 0V.

[0061] like Figure 3 As shown, when the common node K of the first protection module 30 is connected to the body electrode of the Nth transistor 20, the first protection unit 320 is used to conduct negative voltage static electricity. Further, in Figure 3 In region (a), when the negative terminal of the first protection unit 320 is connected to the negative terminal of the second protection unit 340, the first protection unit 320 and the second protection unit 340 work together to conduct negative static electricity. Specifically, when one of the first protection unit 320 and the second protection unit 340 is damaged (e.g., open circuit), the other can still conduct negative static electricity, thereby improving the operational reliability of the first protection module 30.

[0062] In some possible examples, the i-th transistor 20 and the m-th transistor 20 are two adjacent transistors 20, that is, the m-th transistor 20 is the (i-1)-th transistor 20. In other possible examples, the N-th transistor 20 and the q-th transistor 20 are two adjacent transistors 20, that is, the q-th transistor 20 is the (N-1)-th transistor 20. In this case, the first protection unit 320 is connected between two adjacent transistors 20, which can reduce the number of unidirectional conducting elements (e.g., diodes) in the first protection unit 320. This avoids the situation where an excessive number of unidirectional conducting elements connected in series leads to an increase in the overall conduction threshold of the first protection unit 320, thereby affecting ESD performance. It is easy to understand that if the first protection unit 320 is connected between two non-adjacent transistors 20, then a larger number of unidirectional conducting elements need to be connected in series in the first protection unit 320, leading to an increase in the overall conduction threshold and increasing the difficulty of electrostatic conduction.

[0063] In some possible examples, the i-th transistor 20 and the n-th transistor 20 are two adjacent transistors 20, that is, the n-th transistor 20 is the (i+1)-th transistor 20. In other possible examples, the 1-th transistor 20 and the p-th transistor 20 are two adjacent transistors 20, that is, the p-th transistor 20 is the 2-th transistor 20. In this case, the second protection unit 340 is connected between two adjacent transistors 20, which can reduce the number of unidirectional conducting elements (e.g., diodes) in the second protection unit 340. This avoids the situation where an excessive number of unidirectional conducting elements connected in series leads to an increase in the overall conduction threshold of the second protection unit 340, thereby affecting ESD performance. It is easy to understand that if the second protection unit 340 is connected between two non-adjacent transistors 20, then a larger number of unidirectional conducting elements need to be connected in series in the second protection unit 340, leading to an increase in the overall conduction threshold and increasing the difficulty of electrostatic conduction.

[0064] In some possible embodiments, the number of first protection modules 30 is N, and the body electrodes of the N transistors 20 are connected one-to-one with the common node K of the N first protection modules 30. In this case, each first protection module 30 can conduct static electricity to the gate of the next transistor 20, so that the N transistors 20 can be turned on quickly and sequentially under the action of the N first protection modules 30, so that the static discharge speed can be maximized.

[0065] Furthermore, when there are N first protection modules 30, each of the N first protection units 320 is connected between two adjacent transistors 20, and each of the N second protection units 340 is connected between two adjacent transistors 20, so as to maximize the electrostatic discharge speed.

[0066] Please see Figure 4 The diagram illustrates a simulation provided in this embodiment. Curve 41 (pink line) corresponds to the electrostatic response curve of signal port 12 in the related art when the first protection module 30 is not provided; curve 43 (blue line) corresponds to the electrostatic response curve of signal port 12 in this embodiment when the first protection module 30 is provided. The amount of static charge applied to signal port 12 is the same in both cases.

[0067] On the one hand, at the instant of electrostatic application, the peak value of curve 41 is about 135V and the peak value of curve 43 is about 90V, indicating that at the instant of electrostatic impact, the first protection module 30 in this embodiment can make the transistor 20 conduct faster, thereby reducing the overall resistance value of the branch where the N transistors 20 are located, so as to reduce the instantaneous electrostatic voltage value applied to the signal port 12 (the overall voltage drop across the N transistors 20), thereby significantly reducing the damage caused by electrostatics.

[0068] On the other hand, with the first protection module 30 in place, the discharge speed of static electricity is much faster than without the first protection module 30. For example, curve 43 shows that the static voltage at signal port 12 drops to 20V in just 0.1µs; while curve 41 takes 0.2µs to drop to the same level. This indicates that the static discharge speed of the RF switch circuit 100 in this embodiment is twice that of related technologies, which can significantly improve the instantaneous discharge speed of static electricity and improve the ESD performance of the RF switch circuit 100.

[0069] In some other possible embodiments, the number of first protection modules 30 is M, where M is less than N. For example, M can be 1, 2, ..., N-1. The body terminals of the M transistors 20 are connected one-to-one with the common node K of the M first protection modules 30. As an example, the M transistors 20 are the transistors 20 closest to the ground port 14 among the N transistors 20. Specifically, the M transistors 20 can be the Nth transistor 20, the (N-1)th transistor 20, ..., the (N-M+1)th transistor 20. Therefore, this embodiment only sets the first protection modules 30 on the body terminals of some transistors 20, which can save the hardware cost of the RF switch circuit 100 and is also beneficial for the miniaturization design of the RF switch chip configured with the RF switch circuit 100. In other possible examples, the M transistors 20 can be any M of the N transistors 20.

[0070] It should be noted that for transistors 20 whose body electrodes do not have the first protection module 30, static electricity still needs to be conducted to the gate through parasitic capacitance to turn on these transistors 20. When static electricity is transmitted to transistors 20 whose body electrodes have the first protection module 30, under the action of the first protection module 30, the static electricity can be conducted to the gate of the corresponding transistor 20 more quickly, thereby turning on the corresponding transistor 20. Therefore, compared with related technologies, even if the first protection module 30 is provided on the body electrodes of some transistors 20, the electrostatic discharge capability of the RF switching circuit 100 can be improved to a certain extent.

[0071] Please see Figure 5 The first protection unit 320 may include multiple first protection sub-units 3210 connected in the same direction. "Connected in the same direction" means that in two adjacent first protection sub-units 3210, the positive terminal of one first protection sub-unit 3210 is connected to the negative terminal of the other first protection sub-unit 3210. Multiple first protection sub-units 3210 are connected in series to form a first series branch (not shown in the figure). The part connected to one side of the first series branch (…) Figure 5 The positive terminal of the first protection subunit 3210 (the rightmost part of the first protection unit 320) serves as the positive terminal of the first protection unit 320 and is connected to the other side of the first series branch ( Figure 5 The negative terminal of the first protection subunit 3210 (the leftmost part of the first protection unit 320) is used as the negative terminal of the first protection unit 320. For example, the number of first protection subunits 3210 can be 2, 3, 4, 6, etc.

[0072] This embodiment mitigates the harmonic problems generated by a single first protection subunit 3210 by connecting multiple first protection subunits 3210 in series to form a first protection unit 320. Taking a diode as an example, harmonics are generated when the diode is conducting in one direction. When the harmonic level is low, the harmonics generated by the diode will not affect the harmonics generated by the RF switching circuit 100 itself, but will instead have a certain suppression effect on the harmonics generated by the RF switching circuit 100 itself.

[0073] However, when the number of diodes is a single diode, compared to a scheme where multiple diodes are connected in series, the voltage across a single diode becomes two or even three times higher. This increases the third harmonic by at least 9 dB, exceeding the harmonics of the RF switch circuit 100 itself and becoming the main contributor to harmonics, thus worsening the overall harmonics of the RF switch circuit 100. Therefore, this embodiment, by increasing the number of first protection sub-units 3210, can reduce the voltage across a single first protection sub-unit 3210, preventing the overall harmonics from deteriorating.

[0074] Specifically, the first protection subunit 3210 is a component with unidirectional conductivity. As an example, such as... Figure 5 As shown, the first protection subunit 3210 is a diode. For another example, please refer to... Figure 6 The first protection sub-unit 3210 is a field-effect transistor. The gate and drain of the field-effect transistor are shorted to form the positive terminal of the first protection sub-unit 3210, and the source of the field-effect transistor is the negative terminal of the first protection sub-unit 3210.

[0075] In this embodiment, the second protection unit 340 may include multiple second protection sub-units 3410 connected in the same direction. "Connected in the same direction" means that in two adjacent second protection sub-units 3410, the positive terminal of one second protection sub-unit 3410 is connected to the negative terminal of the other second protection sub-unit 3410. Multiple second protection sub-units 3410 are connected in series to form a second series branch (not shown in the figure). The connection to one side of the second series branch (…) Figure 5 The positive terminal of the second protection subunit 3410 (the leftmost part of the second protection unit 340) serves as the positive terminal of the second protection unit 340 and is connected to the other side of the second series branch. Figure 5The negative terminal of the second protection subunit 3410 (the rightmost part of the second protection unit 340) is used as the negative terminal of the second protection unit 340. For example, the number of second protection subunits 3410 can be 2, 3, 4, 6, etc.

[0076] This embodiment uses multiple second protection sub-units 3410 connected in series to form a second protection unit 340, which can alleviate the harmonic problem generated by a single second protection sub-unit 3410. For related information, please refer to the detailed explanation in the specification above, which will not be elaborated further here.

[0077] Specifically, the second protection subunit 3410 is a component with unidirectional conductivity. As an example, such as... Figure 5 As shown, the second protection subunit 3410 is a diode. As another example, such as... Figure 6 As shown, the second protection sub-unit 3410 is a field-effect transistor. The gate and drain of the field-effect transistor are shorted together to form the positive terminal of the second protection sub-unit 3410, and the source of the field-effect transistor is the negative terminal of the second protection sub-unit 3410.

[0078] As an example, when the i-th transistor 20 and the m-th transistor 20 are two adjacent transistors 20, the number of first protection sub-units 3210 is less than or equal to 3. As another example, when the N-th transistor 20 and the q-th transistor 20 are two adjacent transistors 20, the number of first protection sub-units 3210 is less than or equal to 3. Exemplarily, the number of first protection sub-units 3210 can be 2 or 3.

[0079] Since the first protection unit 320 is connected between two adjacent transistors 20, if the number of first protection sub-units 3210 is too large, it will lead to an increase in the overall conduction threshold of the first protection unit 320, thereby affecting ESD performance. Specifically in Figure 5 and Figure 6 In this design, the number of first protection sub-units 3210 is 2, which can reduce the overall conduction threshold of the first protection unit 320, so that static electricity can be conducted to the gate of the corresponding transistor 20 more quickly through the first protection unit 320, thereby improving the conduction speed of the transistor 20 and achieving efficient discharge of static electricity.

[0080] As an example, when the i-th transistor 20 and the n-th transistor 20 are two adjacent transistors 20, the number of second protection sub-units 3410 is less than or equal to 3. As another example, when the 1-th transistor 20 and the p-th transistor 20 are two adjacent transistors 20, the number of second protection sub-units 3410 is less than or equal to 3. Exemplarily, the number of second protection sub-units 3410 can be 2 or 3.

[0081] Since the second protection unit 340 is connected between two adjacent transistors 20, if the number of second protection sub-units 3410 is too large, it will lead to an increase in the overall conduction threshold of the second protection unit 340, thereby affecting ESD performance. Specifically... Figure 5 and Figure 6 In this design, the number of second protection sub-units 3410 is 2, which can reduce the overall conduction threshold of the second protection unit 340, allowing static electricity to be conducted to the gate of the corresponding transistor 20 more quickly through the second protection unit 340, thereby improving the conduction speed of the transistor 20 and achieving efficient discharge of static electricity.

[0082] In some possible embodiments, when the difference between i and m and the difference between n and i are equal, that is, when m, i and n form an arithmetic sequence, the number of the first protection subunit 3210 and the number of the second protection subunit 3410 are equal, so as to improve the symmetry of the overall structure of the first protection module 30.

[0083] In some possible embodiments, when the negative terminal of the first protection unit 320 is connected to the negative terminal of the second protection unit 340, the number of first protection sub-units 3210 and the number of second protection sub-units 3410 are equal. Since the first protection unit 320 and the second protection unit 340 are connected in parallel, when the number of first protection sub-units 3210 and the number of second protection sub-units 3410 are equal, it can be ensured that the overall conduction threshold of the first protection unit 320 and the overall conduction threshold of the second protection unit 340 are approximately equal, thus improving the uniformity of electrostatic conduction.

[0084] In some possible embodiments, the RF switch circuit 100 is applied to an RF front-end module, which has an antenna port (not shown in the figure), and the signal port 12 of the RF switch circuit 100 is connected to the antenna port. Therefore, in this embodiment, the RF switch circuit 100 is a tune switch directly connected to the antenna port. Since the tune switch is directly connected to the antenna port, and the presence of static electricity at the antenna port is particularly significant and the intensity of the static electricity is greater, this embodiment has higher requirements for the electrostatic discharge protection of the RF switch circuit 100.

[0085] As an example, signal port 12 is a signal output port, and the RF switch circuit 100 also has a signal input port, which is connected to the power amplifier (PA) in the RF front-end module. Therefore, in this example, the RF switch circuit 100 is located in the signal transmission path (TX). By improving the ESD performance of the RF switch circuit 100, static electricity at the antenna port can be quickly discharged through the RF switch circuit 100, thereby preventing static electricity from damaging the internal components of the RF front-end module (e.g., the power amplifier), and ensuring the operational reliability of the RF front-end module.

[0086] As another example, signal port 14 is a signal input port, and the RF switch circuit 100 also has a signal output port, which is connected to the low-noise amplifier (LNA) in the RF front-end module. Therefore, in this example, the RF switch circuit 100 is located in the signal receiving path (RX). By improving the ESD performance of the RF switch circuit 100, static electricity at the antenna port can be quickly discharged through the RF switch circuit 100, thereby preventing static electricity from damaging the internal components of the RF front-end module (e.g., the low-noise amplifier), and ensuring the operational reliability of the RF front-end module.

[0087] This application provides a radio frequency (RF) switch circuit 100, which includes a signal port 12 and a ground port 14. The RF switch circuit 100 may include N transistors 20 and at least one first protection module 30. The N transistors 20 are connected in series between the signal port 12 and the ground port 14, and the at least one first protection module 30 is used for conducting static electricity. The first protection module 30 may include a first protection unit 320 and a second protection unit 340. On the one hand, when the signal port 12 is subjected to electrostatic discharge, the positive static electricity will be quickly conducted through the second protection unit 340 to the gate of the transistor 20 (e.g., the nth transistor 20, the pth transistor 20) which is closer to the ground port 14, so that the transistor 20 can be turned on faster, thereby conducting the static electricity to the ground port 14 more efficiently, so as to accelerate the electrostatic discharge speed of the RF switch circuit 100, improve the electrostatic discharge capability of the RF switch circuit 100, and ensure that the RF switch circuit 100 has more reliable ESD performance.

[0088] On the other hand, when the signal port 12 is subjected to electrostatic discharge, the negative voltage static electricity will be quickly conducted through the first protection unit 320 to the gate of the transistor 20 (e.g., the m-th transistor 20, the q-th transistor 20) closer to the signal port 12, so that the transistor 20 can turn on faster, thereby conducting the static electricity to the ground port 14 more efficiently, so as to accelerate the electrostatic discharge speed of the RF switch circuit 100, improve the electrostatic discharge capability of the RF switch circuit 100, and ensure that the RF switch circuit 100 has more reliable ESD performance.

[0089] Furthermore, in this embodiment, the positive terminals of the first protection unit 320 and the second protection unit 340 are connected to the body of the transistor 20, and the negative terminals of the first protection unit 320 and the second protection unit 340 are connected to the gate of the transistor 20. When a control voltage is applied to the gate of the transistor 20, due to the unidirectional conductivity of the first protection unit 320 and the second protection unit 340, the control voltage cannot trigger the first protection unit 320 and the second protection unit 340 to conduct, thus avoiding the situation where the first protection unit 320 and the second protection unit 340 divide the control voltage, and ensuring the normal operation of the RF switching circuit 100.

[0090] Please see Figure 7 This application also provides a radio frequency (RF) switch circuit 100, which has a signal port 12 and a ground port 14. The RF switch circuit 100 may include N transistors 20 and a second protection module 40. The N transistors 20 are connected in series between the signal port 12 and the ground port 14, wherein the transistors 20 are field-effect transistors. For details regarding the transistors 20, please refer to the above description in the specification. To save space, further details are not provided here.

[0091] In this embodiment, the second protection module 40 is used to conduct positive voltage static electricity, and the second protection module 40 has unidirectional conductivity. The second protection module 40 may include a third protection unit 410, the positive terminal of the third protection unit 410 is connected to the body terminal of the first transistor 20, and the negative terminal of the third protection unit 410 is connected to the gate terminal of the p-th transistor 20. The first transistor 20 is the transistor 20 closest to the signal port 12 among the N transistors 20, and p is not 1. Specifically... Figure 7 In the first transistor 20, the source is directly connected to the signal port 12.

[0092] When signal port 12 is subjected to electrostatic discharge, the positive static electricity will be quickly conducted through the third protection unit 410 to the gate of transistor 20 (i.e., the p-th transistor 20) which is closer to ground port 14, so that transistor 20 can turn on faster and conduct static electricity to ground port 14 more efficiently, thereby accelerating the electrostatic discharge speed of RF switch circuit 100, improving the electrostatic discharge capability of RF switch circuit 100, and ensuring that RF switch circuit 100 has more reliable ESD performance.

[0093] Furthermore, in this embodiment, the positive terminal of the third protection unit 410 is connected to the body terminal of the transistor 20, and the negative terminal of the third protection unit 410 is connected to the gate terminal of the transistor 20. When the RF switch circuit 100 is in normal operation, since the DC voltage of the body terminal of the transistor 20 to which the third protection unit 410 is connected is less than the DC voltage of the gate terminal of the transistor 20 to which the third protection unit 410 is connected, when a control voltage is applied to the gate terminal of the transistor 20, due to the unidirectional conductivity of the third protection unit 410, the control voltage cannot trigger the third protection unit 410 to conduct, thus avoiding the situation where the third protection unit 410 divides the control voltage, thereby ensuring the normal operation of the RF switch circuit 100.

[0094] In some possible embodiments, please refer to Figure 8 The third protection unit 410 may include multiple third protection sub-units 4120 connected in the same direction. "Connected in the same direction" means that in two adjacent third protection sub-units 4120, the positive terminal of one third protection sub-unit 4120 is connected to the negative terminal of the other third protection sub-unit 4120. Multiple third protection sub-units 4120 are connected in series to form a third series branch (not shown in the figure). The connection on one side of the third series branch (…) Figure 8 The positive terminal of the third protection subunit 4120 (the leftmost part of the third protection unit 410) is connected to the body terminal of the first transistor 20, and is connected to the other side of the third series branch ( Figure 8 The negative terminal of the third protection sub-unit 4120 (the rightmost part of the third protection unit 410) is connected to the gate of the p-th transistor 20. For example, the number of third protection sub-units 4120 can be 2, 3, 4, 6, etc.

[0095] This embodiment uses multiple third protection sub-units 4120 connected in series to form a third protection unit 410, which can alleviate the harmonic problem generated by a single third protection sub-unit 4120. For related information, please refer to the detailed explanation in the specification above, which will not be elaborated on here.

[0096] Specifically, the third protection subunit 4120 is a unidirectional conductive element. As an example, such as... Figure 8As shown in region (a), the third protection subunit 4120 is a diode. As another example, such as... Figure 8 As shown in region (b), the third protection sub-unit 4120 is a field-effect transistor. The gate and drain of the field-effect transistor are shorted to form the positive terminal of the third protection sub-unit 4120, and the source of the field-effect transistor is the negative terminal of the third protection sub-unit 4120.

[0097] In some possible embodiments, the first transistor 20 and the p-th transistor 20 are two adjacent transistors 20, that is, the p-th transistor 20 is the second transistor 20. In this case, the third protection unit 410 is connected between the two adjacent transistors 20, which can reduce the number of third protection sub-units 4120 (e.g., diodes) and avoid the situation where an excessive number of third protection sub-units 4120 connected in series leads to an increase in the overall conduction threshold of the third protection unit 410, thereby affecting ESD performance. Exemplarily, the number of third protection sub-units 4120 can be less than or equal to 3, for example, 2 or 3, and this embodiment does not specifically limit this.

[0098] It should be noted that, without conflict, the relevant technical features of the above embodiments can also be incorporated into this embodiment. Taking the first protection module 30 as an example, since the body of the first transistor 20 in this embodiment is connected to the second protection module 40, the common node K of the first protection module 30 can be connected to the body of any one of the second to Nth transistors 20. There can be multiple first protection modules 30, and the common node K of the multiple first protection modules 30 is connected one-to-one to the body of the multiple transistors 20, with the common node K of different first protection modules 30 connected to the body of different transistors 20. For a detailed description of the first protection module 30, please refer to the specific explanation above; for brevity, it will not be elaborated further here.

[0099] Please see Figure 9 This application also provides a radio frequency (RF) switch circuit 100, which has a signal port 12 and a ground port 14. The RF switch circuit 100 may include N transistors 20 and a third protection module 50. The N transistors 20 are connected in series between the signal port 12 and the ground port 14, wherein the transistors 20 are field-effect transistors. For details regarding the transistors 20, please refer to the above description in the specification. To save space, further details are not provided here.

[0100] In this embodiment, the third protection module 50 is used to conduct negative voltage static electricity, and the third protection module 50 has unidirectional conductivity. The third protection module 50 may include a fourth protection unit 520, the positive terminal of which is connected to the body of the Nth transistor 20, and the negative terminal of which is connected to the gate of the qth transistor 20. The Nth transistor 20 is the transistor 20 closest to the ground port 14 among the N transistors 20, and q is not N. Specifically... Figure 9 In the Nth transistor 20, the drain is directly connected to the ground port 14.

[0101] When signal port 12 is subjected to electrostatic discharge, the negative voltage static electricity will be quickly conducted through the fourth protection unit 520 to the gate of transistor 20 (i.e., the qth transistor 20) which is closer to signal port 12, so that transistor 20 can turn on faster and conduct static electricity to ground port 14 more efficiently, thereby accelerating the electrostatic discharge speed of RF switch circuit 100, improving the electrostatic discharge capability of RF switch circuit 100, and ensuring that RF switch circuit 100 has more reliable ESD performance.

[0102] Furthermore, in this embodiment, the positive terminal of the fourth protection unit 520 is connected to the body terminal of the transistor 20, and the negative terminal of the fourth protection unit 520 is connected to the gate terminal of the transistor 20. When the RF switch circuit 100 is in normal operation, since the DC voltage of the body terminal of the transistor 20 to which the fourth protection unit 520 is connected is less than the DC voltage of the gate terminal of the transistor 20 to which the fourth protection unit 520 is connected, when a control voltage is applied to the gate terminal of the transistor 20, due to the unidirectional conductivity of the fourth protection unit 520, the control voltage cannot trigger the fourth protection unit 520 to conduct, thus avoiding the situation where the fourth protection unit 520 divides the control voltage, thereby ensuring the normal operation of the RF switch circuit 100.

[0103] In some possible embodiments, please refer to Figure 10 The fourth protection unit 520 may include multiple fourth protection sub-units 5210 connected in the same direction. "Connected in the same direction" means that in two adjacent fourth protection sub-units 5210, the positive terminal of one fourth protection sub-unit 5210 is connected to the negative terminal of the other fourth protection sub-unit 5210. Multiple fourth protection sub-units 5210 are connected in series to form a fourth series branch (not shown in the figure). The connection on one side of the fourth series branch (…) Figure 10 The positive terminal of the fourth protection subunit 5210 (the rightmost part of the fourth protection unit 520) is connected to the body terminal of the Nth transistor 20, and is connected to the other side of the fourth series branch ( Figure 10The negative terminal of the fourth protection sub-unit 5210 (the leftmost part of the fourth protection unit 520) is connected to the gate of the q-th transistor 20. For example, the number of fourth protection sub-units 5210 can be 2, 3, 4, 6, etc.

[0104] This embodiment uses multiple fourth protection sub-units 5210 connected in series to form a fourth protection unit 520, which can alleviate the harmonic problem generated by a single fourth protection sub-unit 5210. For related information, please refer to the detailed explanation in the specification above, which will not be elaborated further here.

[0105] Specifically, the fourth protection subunit 5210 is a component with unidirectional conductivity. As an example, such as... Figure 10 As shown in region (a), the fourth protection subunit 5210 is a diode. As another example, such as... Figure 10 As shown in region (b), the fourth protection sub-unit 5210 is a field-effect transistor. The gate and drain of the field-effect transistor are shorted to form the positive terminal of the fourth protection sub-unit 5210, and the source of the field-effect transistor is the negative terminal of the fourth protection sub-unit 5210.

[0106] In some possible embodiments, the Nth transistor 20 and the qth transistor 20 are two adjacent transistors 20, that is, the qth transistor 20 is the (N-1)th transistor 20. In this case, the fourth protection unit 520 is connected between two adjacent transistors 20, which can reduce the number of fourth protection sub-units 5210 (e.g., diodes). This can avoid the situation where an excessive number of fourth protection sub-units 5210 connected in series leads to an increase in the overall conduction threshold of the fourth protection unit 520, thereby affecting ESD performance. Exemplarily, the number of fourth protection sub-units 5210 can be less than or equal to 3, for example, 2 or 3, and this embodiment does not specifically limit this.

[0107] It should be noted that, without conflict, the relevant technical features in the above embodiments can also be incorporated into this embodiment. For example, the first protection module 30 and the second protection module 40 in the above embodiments can both be incorporated into this embodiment.

[0108] Taking the first protection module 30 as an example, since the body of the first transistor 20 in this embodiment is connected to the second protection module 40, and the body of the Nth transistor 20 is connected to the third protection module 50, in this case, the common node K of the first protection module 30 can be connected to the body of any one of the transistors 20 from the second transistor 20 to the (N-1)th transistor 20. There can be multiple first protection modules 30, and the common node K of multiple first protection modules 30 is connected one-to-one to the body of multiple transistors 20, with the common node K of different first protection modules 30 connected to the body of different transistors 20. Specifically, for a detailed description of the first protection module 30 and the second protection module 40, please refer to the above description in the specification; for the sake of brevity, further details will not be provided here.

[0109] Please see Figure 11 This application also provides a radio frequency (RF) switch circuit 100, which has a signal port 12 and a ground port 14. The RF switch circuit 100 may include N transistors 20 and at least one first protection module 30, where N is an integer greater than 1; for example, N can be 4, 6, 7, 8, 9, etc. Specifically... Figure 11 In this case, N is 9.

[0110] In this embodiment, N transistors 20 are connected in series between the signal port 12 and the ground port 14. The transistors 20 are bipolar transistors, such as heterojunction bipolar transistors (HBTs), bipolar junction transistors (BJTs), etc. It should be noted that "connected in series" means that in two adjacent transistors 20, the collector of one transistor 20 is connected to the emitter of the other transistor 20.

[0111] In this embodiment, at least one first protection module 30 is used for conducting static electricity. The first protection module 30 may include a first protection unit 320 and a second protection unit 340. The positive terminal of the first protection unit 320 is connected to the positive terminal of the second protection unit 340 to form a common node K of the first protection module 30. As an example, when there is only one first protection module 30, the common node K of the first protection module 30 is connected to the body terminal of the i-th transistor 20 in a specified direction H. As another example, when there are multiple first protection modules 30, the common nodes K of the multiple first protection modules 30 are connected one-to-one to the body terminals of the multiple transistors 20; wherein, the specified direction H is the direction from the signal port 12 to the ground port 14.

[0112] When the common node K of the first protection module 30 is connected to the body of the first transistor 20, the negative terminal of the second protection unit 340 is connected to the base of the p-th transistor 20, and the negative terminal of the first protection unit 320 is connected to the negative terminal of the second protection unit 340, or the negative terminal of the first protection unit 320 is left floating. Here, p is not 1.

[0113] When the common node K of the first protection module 30 is connected to the body of any one of the transistors 20 from the second to the (N-1)th transistors 20, the negative terminal of the first protection unit 320 is connected to the base of the m-th transistor 20, and the negative terminal of the second protection unit 340 is connected to the base of the n-th transistor 20. Here, m is greater than or equal to 1 and less than i, and n is greater than i and less than or equal to N.

[0114] When the common node K of the first protection module 30 is connected to the body of the Nth transistor 20, the negative terminal of the first protection unit 320 is connected to the base of the qth transistor 20, and the negative terminal of the second protection unit 340 is connected to the negative terminal of the first protection unit 320 or the negative terminal of the second protection unit 340 is left floating. Here, q is not N.

[0115] In one embodiment, the body of the i-th transistor 20 and the base of the n-th transistor 20 are connected through a second protection unit 340, where i is greater than 1 and less than N, and n is greater than i and less than or equal to N; or, the body of the 1-th transistor 20 and the base of the p-th transistor 20 are connected through the second protection unit 340, where p is not 1. When the signal port 12 is subjected to electrostatic discharge, the positive voltage static electricity will be quickly conducted through the second protection unit 340 to the base of the transistor 20 closer to the ground port 14, enabling the transistor 20 to conduct faster, thereby conducting the static electricity to the ground port 14 more efficiently, accelerating the electrostatic discharge speed of the RF switch circuit 100, improving the electrostatic discharge capability of the RF switch circuit, and ensuring that the RF switch circuit has more reliable ESD performance.

[0116] On the other hand, in this embodiment, the body of the i-th transistor 20 and the base of the m-th transistor 20 are connected through a first protection unit 320, where i is greater than 1 and less than N, and m is greater than or equal to 1 and less than i; or, the body of the N-th transistor 20 and the base of the q-th transistor 20 are connected through the first protection unit 320, where q is not N. When the signal port 12 is subjected to electrostatic discharge, the negative voltage static electricity will be quickly conducted through the first protection unit 320 to the base of the transistor 20 closer to the signal port 12, so that the transistor 20 can conduct faster, thereby conducting the static electricity to the ground port 14 more efficiently, thereby accelerating the electrostatic discharge speed of the RF switch circuit 100, improving the electrostatic discharge capability of the RF switch circuit, and ensuring that the RF switch circuit has more reliable ESD performance.

[0117] Furthermore, in this embodiment, the positive terminals of the first protection unit 320 and the second protection unit 340 are connected to the body terminal of the transistor 20, and the negative terminals of the first protection unit 320 and the second protection unit 340 are connected to the base terminal of the transistor 20. Taking the first protection unit 320 as an example, when the RF switch circuit 100 is in normal operation, since the DC voltage of the body terminal of the transistor 20 connected to the first protection unit 320 is less than the DC voltage of the base terminal of the transistor 20 connected to the first protection unit 320, when a control voltage is applied to the base terminal of the transistor 20, due to the unidirectional conductivity of the first protection unit 320, the control voltage cannot trigger the first protection unit 320 to conduct, thus avoiding the situation where the first protection unit 320 divides the control voltage, ensuring the normal operation of the RF switch circuit. Similarly, for the second protection unit 340, the control voltage applied to the base terminal of the transistor 20 also cannot trigger the second protection unit 340 to conduct, ensuring the normal operation of the RF switch circuit 100.

[0118] In some possible embodiments, the i-th transistor 20 and the m-th transistor 20 are two adjacent transistors 20.

[0119] In some possible embodiments, the i-th transistor 20 and the n-th transistor 20 are two adjacent transistors 20.

[0120] In some possible embodiments, the first transistor 20 and the p-th transistor 20 are two adjacent transistors 20.

[0121] In some possible embodiments, the Nth transistor 20 and the qth transistor 20 are two adjacent transistors 20.

[0122] In some possible embodiments, the number of first protection modules 30 is N, and the body electrodes of the N transistors 20 are connected one-to-one with the common node K of the N first protection modules 30.

[0123] Specifically, the implementation of the first protection unit 320 can be found in the relevant description above. Where there is no conflict, the technical features of the first protection unit 320 in the above embodiments, as well as other technical features included in the RF switch circuit 100, can be incorporated into this embodiment. To save space, they will not be elaborated upon here.

[0124] Please see Figure 12 This application provides a radio frequency (RF) front-end module 200, which is a component that integrates two or more discrete devices such as RF switches, low-noise amplifiers, filters, duplexers, and power amplifiers into a single independent module, thereby improving integration and hardware performance, and miniaturizing the size. In this embodiment, the RF front-end module 200 may include the RF switch circuit 100 described in the previous embodiment.

[0125] This application also provides an electronic device, which can be a 4G or 5G communication device such as a smartphone, tablet, or smartwatch. Specifically, the electronic device may include the radio frequency front-end module 200 from the above embodiments.

[0126] 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 of this application can be applied to 5G radio frequency front-end modules to improve the communication performance of 5G communication equipment.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions 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 this application.

Claims

1. A radio frequency switch circuit, characterized by The radio frequency switch circuit includes a signal port and a ground port, and comprises: N transistors are connected in series between the signal port and the ground port; wherein, the transistors are field-effect transistors; and At least one first protection module for conducting static electricity, the first protection module includes a first protection unit and a second protection unit, the positive terminal of the first protection unit is connected to the positive terminal of the second protection unit to form a common node of the first protection module; When there is only one first protection module, the common node of the first protection module is connected to the body electrode of the i-th transistor in a specified direction; when there are multiple first protection modules, the common nodes of the multiple first protection modules are connected to the body electrodes of the multiple transistors in a one-to-one correspondence; wherein, the specified direction is the direction from the signal port to the ground port. When the common node of the first protection module is connected to the body of the first transistor, the negative terminal of the second protection unit is connected to the gate of the p-th transistor, and the negative terminal of the first protection unit is connected to the negative terminal of the second protection unit or the negative terminal of the first protection unit is left floating; wherein, p is not 1; When the common node of the first protection module is connected to the body of any one of the transistors from the second to the (N-1)th transistor, the negative terminal of the first protection unit is connected to the gate of the mth transistor, and the negative terminal of the second protection unit is connected to the gate of the nth transistor; wherein, m is greater than or equal to 1 and less than i, and n is greater than i and less than or equal to N. When the common node of the first protection module is connected to the body of the Nth transistor, the negative terminal of the first protection unit is connected to the gate of the qth transistor, and the negative terminal of the second protection unit is connected to the negative terminal of the first protection unit or the negative terminal of the second protection unit is left floating; wherein, q is not N.

2. The radio frequency switch circuit of claim 1, wherein, When the common node of the first protection module is connected to the body electrode of the first transistor, the second protection unit is used to conduct positive voltage static electricity; When the common node of the first protection module is connected to the body electrode of any one of the second to N-1 transistors, the first protection unit is used to discharge negative voltage static electricity, and the second protection unit is used to discharge positive voltage static electricity. When the common node of the first protection module is connected to the body electrode of the Nth transistor, the first protection unit is used to conduct negative voltage static electricity.

3. The radio frequency switch circuit of claim 1, wherein, The i-th transistor and the m-th transistor are two adjacent transistors; or / and, The i-th transistor and the n-th transistor are two adjacent transistors; or / and, The first transistor and the p-th transistor are two adjacent transistors; or / and, The Nth transistor and the qth transistor are two adjacent transistors.

4. The radio frequency switch circuit of any one of claims 1 to 3, wherein, The number of the first protection modules is N, and the body electrodes of the N transistors are connected one-to-one with the common node of the N first protection modules.

5. The radio frequency switch circuit of any one of claims 1 to 3, wherein, The number of the first protection modules is M, and the body electrodes of the M transistors are connected one-to-one with the common node of the M first protection modules; Wherein, M is less than N, and the M transistors are the transistors closest to the ground port among the N transistors.

6. The radio frequency switch circuit of any one of claims 1 to 3, wherein, The first protection unit includes multiple first protection sub-units connected in series in the same direction, and the first protection sub-units have unidirectional conductivity; in two adjacent first protection sub-units, the positive terminal of one first protection sub-unit is connected to the negative terminal of the other first protection sub-unit; Multiple first protection sub-units are connected in series to form a first series branch; wherein, the positive terminal of the first protection sub-unit connected to one side of the first series branch is the positive terminal of the first protection unit, and the negative terminal of the first protection sub-unit connected to the other side of the first series branch is the negative terminal of the first protection unit. The second protection unit includes multiple second protection sub-units connected in series in the same direction. Each second protection sub-unit has unidirectional conductivity. In two adjacent second protection sub-units, the positive terminal of one second protection sub-unit is connected to the negative terminal of the other second protection sub-unit. Multiple second protection sub-units are connected in series to form a second series branch; wherein, the positive terminal of the second protection sub-unit connected to one side of the second series branch serves as the positive terminal of the second protection unit, and the negative terminal of the second protection sub-unit connected to the other side of the second series branch serves as the negative terminal of the second protection unit.

7. The radio frequency switch circuit of claim 6, wherein, The first protection subunit is a diode; or, The first protection sub-unit is a field-effect transistor; wherein the gate and drain of the field-effect transistor are shorted to form the positive electrode of the first protection sub-unit, and the source of the field-effect transistor is the negative electrode of the first protection sub-unit.

8. The radio frequency switch circuit of claim 6, wherein, The second protection subunit is a diode; or, The second protection sub-unit is a field-effect transistor; wherein the gate and drain of the field-effect transistor are shorted to form the positive electrode of the second protection sub-unit, and the source of the field-effect transistor is the negative electrode of the second protection sub-unit.

9. The radio frequency switch circuit of claim 6, wherein, When the i-th transistor and the m-th transistor are two adjacent transistors, the number of the first protection sub-units is less than or equal to 3; or / and, When the i-th transistor and the n-th transistor are two adjacent transistors, the number of the second protection sub-units is less than or equal to 3; or / and, When the first transistor and the p-th transistor are two adjacent transistors, the number of the second protection subunits is less than or equal to 3; or / and, When the Nth transistor and the qth transistor are two adjacent transistors, the number of the first protection sub-units is less than or equal to 3.

10. The radio frequency switch circuit of claim 6, wherein, When the difference between i and m and the difference between n and i are equal, the number of the first protection subunit and the number of the second protection subunit are equal; or / and, When the negative terminal of the first protection unit is connected to the negative terminal of the second protection unit, the number of the first protection sub-unit and the number of the second protection sub-unit are equal.

11. The radio frequency switch circuit of any one of claims 1 to 3, wherein, It is used in radio frequency front-end modules, wherein the radio frequency front-end module is provided with an antenna port; The signal port of the radio frequency switch circuit is connected to the antenna port.

12. A radio frequency switch circuit, characterized by The radio frequency switch circuit includes a signal port and a ground port, and comprises: N transistors are connected in series between the signal port and the ground port; wherein, the transistors are field-effect transistors; and The second protection module is used to discharge positive voltage static electricity; the second protection module includes a third protection unit, the positive terminal of which is connected to the body terminal of the first transistor; the negative terminal of which is connected to the gate terminal of the p-th transistor; wherein, the first transistor is the transistor closest to the signal port among the N transistors, and p is not 1.

13. The radio frequency switch circuit of claim 12, wherein, The third protection unit includes multiple third protection sub-units connected in series in the same direction. In two adjacent third protection sub-units, the positive terminal of one third protection sub-unit is connected to the negative terminal of the other third protection sub-unit. Multiple third protection sub-units are connected in series to form a third series branch; wherein, the positive terminal of the third protection sub-unit connected to one side of the third series branch is connected to the body terminal of the first transistor, and the negative terminal of the third protection sub-unit connected to the other side of the third series branch is connected to the gate of the p-th transistor. The third protection sub-unit is a diode; or, the third protection sub-unit is a field-effect transistor, wherein the gate and drain of the field-effect transistor are shorted to form the positive terminal of the third protection sub-unit, and the source of the field-effect transistor is the negative terminal of the third protection sub-unit.

14. A radio frequency switching circuit, characterized in that, The radio frequency switch circuit includes a signal port and a ground port, and comprises: N transistors are connected in series between the signal port and the ground port; wherein, the transistors are field-effect transistors; and The third protection module is used to discharge negative voltage static electricity; the third protection module includes a fourth protection unit, the positive terminal of which is connected to the body terminal of the Nth transistor; the negative terminal of which is connected to the gate terminal of the qth transistor; wherein the Nth transistor is the transistor closest to the grounding port among the N transistors, and q is not N.

15. The radio frequency switching circuit according to claim 14, characterized in that, The fourth protection unit includes multiple fourth protection sub-units connected in series in the same direction. In two adjacent fourth protection sub-units, the positive terminal of one fourth protection sub-unit is connected to the negative terminal of the other fourth protection sub-unit. Multiple fourth protection sub-units are connected in series to form a fourth series branch; wherein, the positive terminal of the fourth protection sub-unit connected to one side of the fourth series branch is connected to the body terminal of the Nth transistor, and the negative terminal of the fourth protection sub-unit connected to the other side of the fourth series branch is connected to the gate terminal of the qth transistor. The fourth protection sub-unit is a diode; or, the fourth protection sub-unit is a field-effect transistor, wherein the gate and drain of the field-effect transistor are shorted to form the positive terminal of the fourth protection sub-unit, and the source of the field-effect transistor is the negative terminal of the fourth protection sub-unit.

16. A radio frequency switching circuit, characterized in that, The radio frequency switch circuit includes a signal port and a ground port, and comprises: N transistors are connected in series between the signal port and the ground port; wherein, the transistors are bipolar transistors; and At least one first protection module for conducting static electricity, the first protection module includes a first protection unit and a second protection unit, the positive terminal of the first protection unit is connected to the positive terminal of the second protection unit to form a common node of the first protection module; When there is only one first protection module, the common node of the first protection module is connected to the body electrode of the i-th transistor in a specified direction; when there are multiple first protection modules, the common nodes of the multiple first protection modules are connected to the body electrodes of the multiple transistors in a one-to-one correspondence; wherein, the specified direction is the direction from the signal port to the ground port. When the common node of the first protection module is connected to the body of the first transistor, the negative terminal of the second protection unit is connected to the base of the p-th transistor, and the negative terminal of the first protection unit is connected to the negative terminal of the second protection unit or the negative terminal of the first protection unit is left floating; wherein, p is not 1. When the common node of the first protection module is connected to the body of any one of the transistors from the second to the (N-1)th transistor, the negative terminal of the first protection unit is connected to the base of the mth transistor, and the negative terminal of the second protection unit is connected to the base of the nth transistor; wherein, m is greater than or equal to 1 and less than i, and n is greater than i and less than or equal to N. When the common node of the first protection module is connected to the body of the Nth transistor, the negative terminal of the first protection unit is connected to the base of the qth transistor, and the negative terminal of the second protection unit is connected to the negative terminal of the first protection unit or the negative terminal of the second protection unit is left floating; wherein, q is not N.

17. The radio frequency switching circuit according to claim 16, characterized in that, The i-th transistor and the m-th transistor are two adjacent transistors; or / and The i-th transistor and the n-th transistor are two adjacent transistors; or / and, The first transistor and the p-th transistor are two adjacent transistors; or / and, The Nth transistor and the qth transistor are two adjacent transistors.

18. The radio frequency switching circuit according to claim 16, characterized in that, The number of the first protection modules is N, and the body electrodes of the N transistors are connected one-to-one with the common node of the N first protection modules.

19. A radio frequency front-end module, characterized in that, include: The radio frequency switching circuit as described in any one of claims 1 to 18.

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