RF switching circuit and chip for optimizing voltage distribution balance of stacked switching transistors

Abstract

The present invention discloses an RF switching circuit and a chip for optimizing the voltage distribution balance of a stacked switching transistor. The RF switching circuit is configured such that the source-drain connections of N switching transistors are stacked, where N is a positive integer and N≥3. Here, the source terminal and the drain terminal of each switching transistor are both connected through a single source-drain bias resistor; the body node of each switching transistor is all connected to a single body node bias resistor, and the bias resistors of the N body nodes are sequentially connected in series, after which the start terminal is connected to the bias voltage source of the body node. Simultaneously, a series-connected diode branch circuit connected to the body node of the switching transistor in an even numbered stage is connected to the source-drain terminal of its own switching transistor, and a series-connected diode branch circuit connected to the body node of the switching transistor in an odd numbered stage is connected to the source-drain terminal of an adjacent switching transistor. When the RF switching circuit is switched off, the leakage current at the body node generated by the switching transistor in each stage flows into the RF main path through the series-connected diode branch circuit and cancels each other out, thereby optimizing the voltage distribution balance of the stacked switching transistor.

Description

Technology Field

[0001] The present invention relates to an RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor, and at the same time, to a chip including said RF switching circuit and a corresponding electronic device, and belongs to the field of RF integrated circuit technology. Background Technology

[0002] The RF switching circuit is a critical component of the RF front-end module, playing a role in accurately switching the transmission path of RF signals to select and open the corresponding RF path; when using a common antenna in a wireless communication system, it enables the reception and transmission of RF signals; and it can also be applied to antenna impedance tuning to improve antenna efficiency. In conventional technology, RF switching circuits generally operate in high-voltage and high-power environments and must withstand significant voltage fluctuations. A common method to improve the power and voltage withstand capabilities of RF switching circuits is the use of a stacked structure of switching transistors. That is, the RF switching circuit is composed of multiple stages of switching transistors connected in series. However, uneven voltage distribution exists in RF switching circuits with such a stacked structure, generating a large amount of harmonics, which limits the power and voltage withstand capabilities of the RF switching circuit. This affects the signal processing capabilities of the RF transceiver, degrading the communication quality of the communication system, and reduces antenna efficiency when the RF switching circuit is used for antenna impedance tuning. The problem to be solved

[0003] The main technical problem that the present invention aims to solve is to provide an RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor.

[0004] Another technical problem that the present invention aims to solve is to provide a chip including the said RF switching circuit and a corresponding electronic device. means of solving the problem

[0005] To achieve the above-mentioned purpose, the present invention adopts the technical solution described below.

[0006] According to a first aspect of an embodiment of the present invention, an RF switching circuit is provided that optimizes the voltage distribution balance of stacked switching transistors, wherein the source-drain connections of N switching transistors are stacked, N is a positive integer and N≥3.

[0007] The source terminal and drain terminal of each of the above switching transistors are both connected through a single source-drain bias resistor; the body node of each of the above switching transistors is all connected to a single body node bias resistor, and N body node bias resistors are sequentially connected in series, and then the start terminal is connected to the body node bias voltage source.

[0008] At the same time, the body nodes of the switching transistors in the first stage are all connected to the drain terminals of the switching transistors in the second stage through a one- or two-strand branch circuit composed of the positive and negative terminals of X diodes connected in series.

[0009] The body node of the switching transistor in the middle even-numbered terminal is connected to the source and drain terminals of each switching transistor through a single-strand branch circuit composed of the positive and negative terminals of X or Y diodes connected in series; the body node of the switching transistor in the middle odd-numbered terminal is connected to the source terminal of the switching transistor in the previous terminal and the drain terminal of the switching transistor in the next terminal through a single-strand branch circuit composed of the positive and negative terminals of X diodes connected in series.

[0010] The body nodes of the switching transistors in the Nth stage are all connected to the source terminals of the switching transistors in the N-1th stage through a one- or two-strand branch circuit composed of the positive and negative terminals of X diodes connected in series.

[0011] X and Y are both positive integers, and also X≥1 and Y≤X; and the positive terminals of the branch circuits formed by connecting the positive and negative terminals of the diodes in series are all connected to the body nodes of the switching transistors.

[0012] Preferably, when the RF switching circuit is in a cut-off state, if the voltage difference between the source and drain terminals of the switching transistor reaches the conduction voltage of the series-connected diode branch circuit, the series-connected diode branch circuit conducts and becomes a low-impedance path, and the current leaking from the body node of the switching transistor flows through the low-impedance path to the source and drain terminals of the switching transistor itself or to the source and drain terminals of an adjacent switching transistor, and then cancels each other out. This prevents the performance of the RF switching circuit from degrading due to an increase in the body node bias voltage of the switching transistor and optimizes the voltage distribution balance of the stacked switching transistor.

[0013] Preferably, when the RF switching circuit is in a conducting state, the voltages across the series-connected diode branch circuits become equal and short-circuited, resulting in an open circuit state.

[0014] Preferably, the gate terminals of each of the switching transistors are all connected to a bias resistor of a single gate terminal, and N bias resistors of the gate terminals are sequentially connected in series, after which the start terminal is connected to a bias voltage source of the gate terminal.

[0015] Preferably, if the source-drain voltage difference of the switching transistor satisfies the conduction condition of the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal but does not satisfy the conduction condition of the series-connected diode branch circuit connected to the body node of the switching transistor in the even-numbered terminal, the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal conducts first, and the current leaking from the body node of the switching transistor in the even-numbered terminal first passes through one body node bias resistor, then passes through the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal, and flows to the source-drain node of the transistor in the RF switching circuit.

[0016] Preferably, when the source-drain voltage difference of the switching transistor simultaneously satisfies the conduction condition of the series-connected diode branch circuit connected to the body node of the switching transistor at the odd-numbered terminal and the switching transistor at the even-numbered terminal, the series-connected diode branch circuit connected to the body node of the switching transistor at the odd-numbered terminal and the switching transistor at the even-numbered terminal conducts simultaneously, and the current leaking from the body node of the switching transistor flows to the source-drain node of the transistor in the RF switching circuit through a low-impedance path.

[0017] Preferably, in a series-connected diode branch circuit connected to the body node of the switching transistor, the number of diodes is determined by the difference between the conduction voltage of the series-connected diode branch circuit and the source-drain voltage of the switching transistor.

[0018] According to a second aspect of an embodiment of the present invention, an integrated circuit chip comprising an RF switching circuit that optimizes the voltage distribution balance of the stacked switching transistors described above is provided.

[0019] According to a third aspect of an embodiment of the present invention, an electronic device comprising an RF switching circuit that optimizes the voltage distribution balance of the stacked switching transistor described above is provided. Effects of the invention

[0020] Compared to conventional technology, the RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor provided in the present invention utilizes a technical solution in which a series-connected diode branch circuit is installed at the body node of the switching transistor in each stage, thereby introducing the leakage current generated at the body node of the switching transistor in each stage into the RF main path and canceling each other out. This optimizes the voltage distribution balance of the stacked switching transistor, further improving the linearity and power processing capability of the RF switching circuit. Therefore, the RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor provided in the present invention has beneficial effects such as a sophisticated and rational structural design, low design costs, and excellent circuit performance. Brief explanation of the drawing

[0021] FIG. 1 is a schematic circuit diagram showing a typical RF switching circuit in the prior art. FIG. 2 is a schematic circuit diagram showing an RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor provided in an embodiment of the present invention. FIG. 3 is a figure comparing a simulation test of the second harmonic of an RF switching circuit according to a conventional technical solution and a technical solution of the present invention in an embodiment of the present invention. Figure 4 is a figure comparing a simulation test of the third harmonic of an RF switching circuit according to a conventional technical solution and a technical solution of the present invention in an embodiment of the present invention. FIG. 5 is a figure comparing a simulation test of the source-drain terminal voltage of an RF switching circuit according to a conventional technical solution and a technical solution of the present invention in an embodiment of the present invention. FIG. 6 is a schematic diagram showing an electronic device using an RF switching circuit provided in the present invention. Specific details for implementing the invention

[0022] The technical details of the present invention will be described in detail below by combining the attached drawings and specific embodiments.

[0023] To aid understanding and explanation, a conventional technical solution, the RF switching circuit, is first briefly introduced, and based on this, a specific technical solution according to an embodiment of the present invention is described in detail.

[0024] A general RF switching circuit in the prior art is as illustrated in FIG. 1. The RF switching circuit comprises N (N is a positive integer, and N≥3) switching transistors (M1~M N The source-drain connections of ) are stacked. Here, the source and drain terminals of each switching transistor are both connected through a single source-drain bias resistor (Rds); and the gate terminals of each switching transistor are all connected through a single gate terminal bias resistor (R G It is connected to ), and the bias resistors (R) of the N gate terminals G ) are sequentially connected in series, after which the start terminal (GC) is connected to the bias voltage source (Vg) of the gate terminal; and the body node of each switching transistor is all connected to the bias resistor (R) of a single body node. B It is connected to ), and the bias resistance (R) of the N body nodes B After the ) are sequentially connected in series, the start terminal (BC) is connected to the bias voltage source (Vb) of the body node.

[0025] Generally, when the RF switching circuit is conducted, the bias voltage (Vg) at the gate terminal is 2.5V and the bias voltage (Vb) at the body node is 0V; when the RF switching circuit is cut off, the bias voltage (Vg) at the gate terminal is -2.5V and the bias voltage (Vb) at the body node is -2.5V, and the conduction and cut-off states of the RF switching circuit are controlled by changing the voltage values ​​of the bias voltage (Vg) at the gate terminal and the bias voltage (Vb) at the body node. Here, the source-drain bias resistor (Rds) provides a DC cut-off potential to the cut-off switching transistor, thereby preventing charge from accumulating at the source-drain node of the switching transistor and causing the switching transistor to be destroyed prematurely.

[0026] Due to structural causes inherent to the switching transistor device itself, parasitic diodes exist between the body node, source terminal, and drain terminal of each switching transistor. For example, in FIG. 1, a parasitic diode (Dbs1) exists between the body node (B1) and the source terminal (S1) of the switching transistor (M1) in the first stage, and a parasitic diode (Dbd1) exists between the body node (B1) and the drain terminal (D1). When the RF switching circuit is in a conducting state, each switching transistor short-circuits the parasitic diodes present within itself. That is, the presence of parasitic diodes does not affect the conduction resistance of the path of the RF switching circuit in a conducting state.

[0027] When the RF switching circuit is in a cutoff state, particularly when the RF switching circuit used for antenna impedance tuning is generally in a cutoff state, a voltage difference occurs between the source and drain terminals of the stacked-connection switching transistor; furthermore, as the power value of the RF signal increases, this voltage difference becomes larger. When this voltage difference increases to a certain extent, the parasitic diode located between the body node and the source terminal or between the body node and the drain terminal conducts, causing a leakage current (iB) to occur at the body node. The leakage current (iB) at the body node is [related to] the bias resistance (R) of the body node. B By lowering the voltage at ), the bias voltage of the body node is increased. The degree to which the bias voltage of the body node is increased is closely related to the number of series-connected switching transistors. The greater the number of series-connected switching transistors, the lower the bias resistance (R) of the body node of the switching transistor (M1) in the first stage. B The total current leaking from the body node flowing through the switching transistor increases, and the bias voltage of the body node also rises significantly. When the bias voltage of the body node of the switching transistor rises, a large amount of harmonics is rapidly generated in the RF switching circuit, making nonlinearity more pronounced. At the same time, it exacerbates the imbalance in voltage distribution in the switching transistor of the stacked connection structure, which can cause the switching transistor to be destroyed more easily and significantly reduce the power processing capability of the RF switching circuit.

[0028] To solve the aforementioned problems existing in the prior art, an embodiment of the present invention provides an RF switching circuit that optimizes the voltage distribution balance of stacked switching transistors, as illustrated in FIG. 2. The RF switching circuit comprises N (N is a positive integer and N≥3) switching transistors (M1~M NThe source-drain connections of ) are stacked. Here, the source and drain terminals of each switching transistor are both connected through a single source-drain bias resistor (Rds); and the gate terminals of each switching transistor are all connected through a single gate terminal bias resistor (R G It is connected to ), and the bias resistors (R) of the N gate terminals G After being sequentially connected in series, the start terminal (GC) is connected to the bias voltage source (Vg) of the gate terminal. The body node of each switching transistor is all connected to the bias resistor (R) of a single body node. B It is connected to ), and the bias resistance (R) of the N body nodes B After being sequentially connected in series, the start terminal (BC) is connected to the bias voltage source (Vb) of the body node. At the same time, the body node of the switching transistor in the first stage is also connected to the drain terminal of the switching transistor in the second stage through a two-strand branch circuit composed of the positive and negative terminals of X diodes (where X is a positive integer and X≥1) connected in series. The body node of the switching transistor in the middle even stage is connected to the source terminal and drain terminal of each switching transistor through a one-strand branch circuit composed of the positive and negative terminals of X diodes connected in series. The body node of the switching transistor in the middle odd stage is connected to the source terminal of the switching transistor in the previous stage and the drain terminal of the switching transistor in the next stage through a one-strand branch circuit composed of the positive and negative terminals of X diodes connected in series. The body nodes of the switching transistors in the Nth stage (final stage) are all connected to the source terminals of the switching transistors in the N-1th stage through a two-strand branch circuit composed of the positive and negative terminals of X diodes connected in series. Here, the positive terminals of the branch circuit composed of the positive and negative terminals of X diodes connected in series are all connected to the body nodes of the switching transistors.

[0029] When the RF switching circuit is in a conducting state, the source terminal voltage (V) of each switching transistor S ) and drain terminal voltage (V D Since ) are all the same, the voltage of the body node (V B ) is V B = (V S +V D ) / 2 + Vb, where, since the bias voltage (Vb) of the body node is 0V, the voltage of the body node is also the same as the voltage of the source-drain terminal. Therefore, the branch circuit formed by connecting the positive and negative terminals of each X diode in series is equivalent to a short circuit and is in an open circuit state, so it does not affect the conduction resistance of the RF signal path.

[0030] When the RF switching circuit is in the cutoff state, if the source-drain terminal voltage difference of the stacked-connection switching transistor reaches the conduction voltage of the series-connected diode branch circuit, the corresponding branch circuit composed of the positive and negative terminals of X diodes connected in series is in a conduction state, which is due to the bias resistance (R) of each body node. B Compared to the bias network composed of ), the branch circuit composed of the positive and negative terminals of the corresponding diode connected in series is a low-impedance path. Therefore, the leakage current (iB) at the body node, which is caused by the parasitic diode between the body node and the source terminal or between the body node and the drain terminal conducting due to an increase in the voltage difference between the source and drain terminals of the switching transistor, is no longer due to the bias resistance (R) of the body node. BThe current does not pass through a bias network composed of the diodes, but instead flows to the source and drain terminals of the switching transistor itself or to the source and drain terminals of an adjacent switching transistor through a branch circuit formed by connecting the positive and negative terminals of the diodes in series. Additionally, the leakage current (iB) of each body node passes through a bias resistor (Rds) located between the source and drain terminals and then cancels each other out. Therefore, the phenomenon in which the bias voltage of the body node rises and degrades the performance of the RF switching circuit does not occur, and by optimizing the voltage distribution balance of the stacked switching transistors and preventing the generation of a large amount of harmonics, the linearization of the RF switching circuit is improved, and the power processing capability of the RF switching circuit is significantly enhanced.

[0031] When the source-drain voltage difference of the switching transistor is small—that is, when the voltage difference satisfies the conduction condition of the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal but does not satisfy the conduction condition of the series-connected diode branch circuit connected to the body node of the switching transistor in the even-numbered terminal—the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal conducts first, and the current leaking from the body node of the switching transistor in the even-numbered terminal first passes through one body node bias resistor (R B After passing through ), it flows through a series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal and to the source-drain node of the transistor in the RF switching circuit.

[0032] When the source-drain voltage difference of a switching transistor is large, that is, when such voltage difference simultaneously satisfies the conduction condition of the series-connected diode branch circuit connected to the body nodes of the switching transistor in the odd-numbered terminal and the switching transistor in the even-numbered terminal, the series-connected diode branch circuit connected to the body nodes of the switching transistor in the odd-numbered terminal and the switching transistor in the even-numbered terminal conducts simultaneously, the leakage current path in the series-connected diode branch circuit connected to the body node of the switching transistor in the even-numbered terminal is additionally increased, and the current leaking from the body node of the switching transistor in the odd-numbered terminal is also one body node bias resistor (R B Through ), it passes through the series-connected diode branch circuit connected to the body node of the switching transistor in the even-numbered terminal, and further flows to the source-drain node of the transistor in the RF switching circuit, thereby preventing the series-connected diode branch circuit of the switching transistor in the odd-numbered terminal from being destroyed.

[0033] In one embodiment of the present invention, the body node of a switching transistor at the first stage of the RF switching circuit and the body node of a switching transistor at the Nth stage (final stage) are both connected to the drain terminal or source terminal of an adjacent switching transistor through a two-strand branch circuit composed of the positive and negative terminals of X diodes connected in series. In another embodiment of the present invention, the body node of a switching transistor at the first stage of the RF switching circuit and the body node of a switching transistor at the Nth stage (final stage) may also be connected to the drain terminal or source terminal of an adjacent switching transistor through a one-strand branch circuit composed of the positive and negative terminals of X diodes connected in series, and this does not affect the optimization performance of the circuit.

[0034] In one embodiment of the present invention, a series-connected diode branch circuit connected to the body node of a switching transistor at an odd-numbered terminal and a series-connected diode branch circuit connected to the body node of a switching transistor at an even-numbered terminal in an RF switching circuit are both configured with the positive and negative terminals of X diodes connected in series. In another embodiment of the present invention, depending on the requirements of the RF circuit, a technical solution may be adopted in which the series-connected diode branch circuit connected to the body node of a switching transistor at an odd-numbered terminal is configured with the positive and negative terminals of X diodes connected in series, and the series-connected diode branch circuit connected to the body node of a switching transistor at an even-numbered terminal is configured with the positive and negative terminals of Y diodes connected in series. Here, Y is a positive integer, and also Y ≤ X.

[0035] It should be noted that in a branch circuit composed of X diodes with their positive and negative terminals connected in series, the value of the number of diodes X is generally determined by the difference between the conduction voltage of the branch circuit and the source-drain voltage of the switching transistor.

[0036] In a conventional technical solution RF switching circuit, as the number of series-connected switching transistors increases, the bias resistance (R) of the body node of the switching transistor (M1) in the first stage B As the total current leaking from the body node passing through ) increases, the bias voltage of that body node rises more significantly, and the nonlinearity of the RF switching circuit becomes more pronounced. The technical effect implemented by the embodiment of the present invention is the exact opposite. In the embodiment of the present invention, in the case of an RF switching circuit configured by stacking the source-drain connections of N switching transistors, the larger the number of switching transistors N, the more pronounced the performance of optimizing the voltage distribution balance and linearization of the stacked switching transistors becomes, and the power processing capability is also more clearly improved.

[0037] In order to verify the superior performance of the RF switching circuit that optimizes the voltage distribution balance of the stacked switching transistor provided in the embodiment of the present invention, the inventor performed simulation comparison tests for various performances on the RF switching circuit and an RF switching circuit adopting a conventional technical solution, respectively, and the test results are as shown in FIGS. 3, 4, and 5.

[0038] Figure 3 shows a simulation test curve for the second harmonic of an RF switching circuit, where the horizontal axis represents input power and the vertical axis represents the second harmonic, with all units in dBm. As shown in Figure 3, when the input power is low, the second harmonic generated in the RF switching circuit provided in the embodiment of the present invention generally matches that of the RF switching circuit using a conventional technical solution. However, as the input power increases, the second harmonic generated in the RF switching circuit provided in the embodiment of the present invention is significantly smaller than that generated in the RF switching circuit using a conventional technical solution, and the performance of the second harmonic is greatly optimized.

[0039] Figure 4 shows a simulation test curve for the third harmonic of an RF switching circuit, where the horizontal axis represents input power and the vertical axis represents the third harmonic, with all units in dBm. As shown in Figure 4, when the input power is low, the third harmonic generated in the RF switching circuit provided in the embodiment of the present invention generally matches that of the RF switching circuit using a conventional technical solution. However, as the input power increases, the third harmonic generated in the RF switching circuit provided in the embodiment of the present invention is significantly smaller than that generated in the RF switching circuit using a conventional technical solution, and the performance of the third harmonic is greatly optimized.

[0040] Figure 5 shows the results of a simulation test on the source-drain terminal voltage of an RF switching circuit. The test circuit is an RF switching circuit in which 24 switching transistors are stacked and connected, and the test input power is 48 dBm. In Figure 5, the horizontal axis represents the switching transistors in each stage (stages 1 through 24), and the vertical axis represents the actual voltage value of the source-drain terminal voltage (Vds) of the switching transistors, with the unit being volts (V). In Figure 5, it can be seen that compared to an RF switching circuit adopting a conventional technical solution, the RF switching circuit provided in the embodiment of the present invention has a large difference in the source-drain terminal voltage (Vds) of the switching transistors in each stage, with a maximum difference of about 0.35 V, whereas in the RF switching circuit provided in the embodiment of the present invention, the source-drain terminal voltage (Vds) of the switching transistors in each stage is relatively balanced, with a maximum difference of only about 0.05 V. This explains that the RF switching circuit provided in the embodiment of the present invention effectively optimizes the voltage distribution balance of a stacked switching transistor, thereby preventing the generation of a large amount of harmonics, which can further improve linearization and enhance power processing capability.

[0041] The structure and operating principle of the RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor provided in the present invention have been described in detail above. Based on the said RF switching circuit, an embodiment of the present invention further provides an integrated circuit chip comprising the RF switching circuit for optimizing the voltage distribution balance of the stacked switching transistor described above. The integrated circuit chip serves as an important component of the RF front-end module in a wireless communication system and can accurately switch the transmission path of an RF signal and select and open a corresponding RF path; can implement the reception and transmission of RF signals when antennas are shared in a wireless communication system; and can be applied to antenna impedance tuning to improve antenna efficiency. The specific structure of the RF switching circuit for optimizing the voltage distribution balance of the stacked switching transistor in the said integrated circuit chip is not described in further detail here.

[0042] In addition, the RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor provided in the present invention can be used in electronic devices as an important component of a communication component. The electronic devices mentioned herein can be used in mobile environments and refer to computing devices that support various communication methods such as GSM, EDGE, CDMA, TD_SCDMA, WCDMA, TDD_LTE, FDD_LTE, NR, etc., including mobile phones, laptop computers, tablet computers, and automotive computers. Furthermore, the technical solution provided in the present invention is also applicable to other RF integrated circuit application scenarios, such as communication base stations and intelligent network vehicles.

[0043] As illustrated in FIG. 6, the electronic device comprises at least a processor, memory, and a communication assembly, and may additionally include a sensor assembly, a power assembly, a multimedia assembly, and an input / output interface depending on actual needs. Here, the memory, communication assembly, sensor assembly, power assembly, multimedia assembly, and input / output interface are all connected to the corresponding processor. The memory may be static random access memory (SRAM), electrically eraseable programmable read-only memory (EEPROM), eraseable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, etc. The processor may be a central processing unit (CPU), a graphics processor (GPU), a field programmable logic gate array (FPGA), an application-specific integrated circuit (ASIC), a digital signal processing (DSP) chip, etc. Other communication assemblies, sensor assemblies, power assemblies, multimedia assemblies, etc., may all be implemented using general-purpose components and are not specifically described herein.

[0044] To summarize the above, compared to conventional technology, the RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor provided in the present invention utilizes a technical solution in which a series-connected diode branch circuit is installed at the body node of the switching transistor in each stage, thereby introducing the leakage current generated at the body node of the switching transistor in each stage into the RF main path and canceling each other out. This optimizes the voltage distribution balance of the stacked switching transistor, further improving the linearity and power processing capability of the RF switching circuit. Therefore, the RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor provided in the present invention offers beneficial effects such as a sophisticated and rational structural design, low design costs, and excellent circuit performance.

[0045] It should be noted that the terms “first” and “second” are used solely for illustrative purposes and should not be understood as indicating or implying relative importance, or as implicitly indicating the number of described technical features. Accordingly, the features limited to “first” and “second” may explicitly or implicitly include one or more such features. In the description of the invention, the meaning of “plural” refers to two or more unless otherwise clearly and specifically defined.

[0046] The RF switching circuit and chip for optimizing the voltage distribution balance of a stacked switching transistor provided in the present invention have been described in detail above. To those skilled in the art, all obvious modifications made to the present invention, provided they do not depart from the substantial scope of the invention, are infringements of the patent rights of the present invention and result in corresponding legal liability.

Claims

Claim 1 An RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor, wherein the source-drain connections of N switching transistors are stacked and N is a positive integer and N≥3; the source terminal and drain terminal of each of the switching transistors are all connected through a single source-drain bias resistor; the body nodes of each of the switching transistors are all connected to a single body node bias resistor, and the bias resistors of N of the body nodes are sequentially connected in series, and then the start terminal is connected to a bias voltage source of the body node; simultaneously, the body nodes of the switching transistors in the first stage are all connected to the drain terminal of the switching transistor in the second stage through a branch circuit consisting of one or two strands formed by the positive and negative terminals of X diodes connected in series; and the body nodes of the switching transistors in the intermediate even stages are each connected to the source terminal and drain terminal of the switching transistor through a branch circuit consisting of the positive and negative terminals of X or Y diodes connected in series. An RF switching circuit for optimizing voltage distribution balance of a stacked switching transistor, characterized in that the body node of the switching transistor in the middle odd-numbered terminal is connected to the source terminal of the switching transistor in the previous terminal and the drain terminal of the switching transistor in the next terminal through a single-strand branch circuit composed of the positive and negative terminals of X diodes connected in series; the body node of the switching transistor in the Nth terminal is connected to the source terminal of the switching transistor in the N-1th terminal through a single-strand or two-strand branch circuit composed of the positive and negative terminals of X diodes connected in series; X and Y are both positive integers, and X≥1, Y≤X; and the positive terminal of the branch circuit composed of the positive and negative terminals of the diodes connected in series is connected to the body node of the switching transistor. Claim 2 An RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor, characterized in that, in the first paragraph, when the RF switching circuit is in a cut-off state, if the voltage difference between the source and drain terminals of the switching transistor reaches the conduction voltage of the series-connected diode branch circuit, the series-connected diode branch circuit conducts to become a low-impedance path, and the current leaking from the body node of the switching transistor flows through the low-impedance path to the source and drain terminals of the self-switching transistor or the source and drain terminals of an adjacent switching transistor and then cancels each other out. Claim 3 An RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor, characterized in that, in the first paragraph, when the RF switching circuit is in a conducting state, the voltage across the series-connected diode branch circuit becomes equal and short-circuited, resulting in an open-circuit state. Claim 4 An RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor, characterized in that, in claim 2 or 3, the gate terminals of each switching transistor are all connected to a bias resistor of a single gate terminal, and N bias resistors of the gate terminals are sequentially connected in series, and then the start terminal is connected to a bias voltage source of the gate terminal. Claim 5 An RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor, wherein, in the first paragraph, when the source-drain voltage difference of the switching transistor satisfies the conduction condition of a series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal but does not satisfy the conduction condition of a series-connected diode branch circuit connected to the body node of the switching transistor in the even-numbered terminal, the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal conducts first, and the current leaking from the body node of the switching transistor in the even-numbered terminal first passes through one body node bias resistor, then passes through the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal, and flows to the source-drain node of the transistor in the RF switching circuit. Claim 6 An RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor, wherein, in claim 1, when the source-drain voltage difference of the switching transistor simultaneously satisfies the conduction condition of a series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal and the switching transistor in the even-numbered terminal, the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal and the switching transistor in the even-numbered terminal conducts simultaneously, and the current leaking from the body node of the switching transistor flows to the source-drain node of the transistor in the RF switching circuit through a low-impedance path. Claim 7 An RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor, characterized in that, in a series-connected diode branch circuit connected to the body node of the switching transistor according to claim 1, the number of diodes is determined according to the conduction voltage of the series-connected diode branch circuit and the source-drain voltage difference of the switching transistor. Claim 8 An RF switching circuit for optimizing the voltage distribution balance of a stacked switching transistor, wherein the RF switching circuit is configured such that the source-drain connections of N switching transistors are stacked, N is a positive integer and N≥3; the source terminal and drain terminal of each of the switching transistors are all connected through a single source-drain bias resistor; the body node of each of the switching transistors is all connected to a single body node bias resistor, and the bias resistors of N of the body nodes are sequentially connected in series, after which the start terminal is connected to a bias voltage source of the body node; and simultaneously, the body node of the switching transistor in the first stage is all connected to the drain terminal of the switching transistor in the second stage through a branch circuit consisting of one or two strands, the positive and negative terminals of X diodes connected in series. The body nodes of the switching transistors in the middle even-numbered terminals are connected to the source and drain terminals of each switching transistor through a single branch circuit composed of the positive and negative terminals of X diodes connected in series, or to the source and drain terminals of each switching transistor through a single branch circuit composed of the positive and negative terminals of Y diodes connected in series; the body nodes of the switching transistors in the middle odd-numbered terminals are connected to the source terminal of the switching transistor in the previous terminal and the drain terminal of the switching transistor in the next terminal through a single branch circuit composed of the positive and negative terminals of X diodes connected in series; the body nodes of the switching transistors in the Nth terminal are all connected to the source terminal of the switching transistor in the N-1th terminal through a single or two branch circuit composed of the positive and negative terminals of X diodes connected in series; X and Y are both positive integers, and also X ≥ 1 and Y ≤ X;The positive terminals of the branch circuits, formed by connecting the positive and negative terminals of each diode in series, are all connected to the body nodes of the switching transistors; When the above RF switching circuit is in a cut-off state, if the source-drain voltage difference of the switching transistor satisfies only the conduction condition of the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal, the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal conducts, and the current leaking from the body node of the switching transistor in the even-numbered terminal first passes through the bias resistor of the body node, then passes through the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal, and flows to the source-drain node of the switching transistor; if the source-drain voltage difference of the switching transistor simultaneously satisfies the conduction condition of the series-connected diode branch circuit connected to the body node of the switching transistor in the odd-numbered terminal and the switching transistor in the even-numbered terminal, each series-connected diode branch circuit conducts simultaneously, and the current leaking from the body node of each said switching transistor passes through a low-impedance path and flows to the source-drain node of the switching transistor; An RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor, characterized in that the currents leaking from each body node cancel each other out after passing through the source-drain bias resistor. Claim 9 An integrated circuit chip characterized by including an RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor according to any one of claims 1 to 8. Claim 10 An electronic device characterized by including an RF switching circuit that optimizes the voltage distribution balance of a stacked switching transistor according to any one of claims 1 to 8.

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