Radio frequency switch circuit for high-power application and corresponding electronic equipment

Abstract

The utility model discloses a radio frequency switch circuit for high-power application and corresponding electronic equipment. According to the radio frequency switch circuit, through the innovative cross feedback structure, the excellent technical effect is achieved, and particularly, the radio frequency switch circuit has outstanding performance in the aspects of high power bearing capacity and high harmonic processing capacity. Body end connecting diodes of the main circuit and the branch circuit are completely separated from source ends and drain ends of switching transistors in respective circuits, so that internal connection is fundamentally avoided, a nonlinear effect caused by parasitic diodes can be effectively reduced, and harmonic distortion is reduced. Therefore, the radio frequency switch circuit not only has high power bearing capacity, but also can bear large voltage fluctuation and maintain definition and accuracy of communication signals; the radio frequency switch circuit also has high harmonic wave processing capability, can effectively reduce harmonic wave interference caused by high-power signals, and meets strict requirements of a wireless communication system on the radio frequency switch circuit.

Description

Technical Field

[0001] The utility model relates to a radio frequency switch circuit for high-power applications, and also relates to electronic equipment comprising the radio frequency switch circuit, belonging to the technical field of radio frequency integrated circuits. Background Art

[0002] RF switching circuits are key components in RF front-end modules. Their function is to accurately switch the transmission path of RF signals, thereby enabling the appropriate RF path. Since RF transceivers are typically located at the front end of wireless communication devices, the performance of RF switching circuits directly impacts the performance of the entire communication system. In addition to basic signal switching functions, RF switching circuits are also widely used for antenna impedance tuning, which helps improve antenna efficiency. In wireless communication systems, due to the frequent need to operate at high power levels, RF switching circuits must withstand significant voltage fluctuations. Therefore, the power handling capability of RF switching circuits is directly related to the communication quality of the wireless communication system. Specifically, the greater the power handling capability of an RF switching circuit, the higher the signal quality it transmits. Therefore, designing an RF switching circuit with high power handling capability and high harmonic handling capabilities is crucial for wireless communication systems.

[0003] In RF switching circuit design, due to the inherent characteristics of switching transistors, two parasitic diodes naturally form at the body of each switching transistor, one between the body and the source, and one between the body and the drain. This structure is common in RF switching circuits. When the RF switching circuit is in the on state, the conduction of the main switching transistor causes these parasitic diodes to be reverse biased, effectively short-circuiting them. Therefore, at this stage, the parasitic diodes have little effect on the circuit's on-resistance and can be ignored. However, when RF switching circuits are used for antenna impedance tuning and often need to be in the off state, the problem becomes more complex. In the off state, due to the internal structure of the switching transistor, a voltage difference develops between the source and drain terminals. This voltage difference increases with increasing input power. Once the voltage difference reaches a certain threshold, the parasitic diodes between the body and the source, or between the body and the drain, become forward-biased and conduct, generating body leakage current. This body leakage current creates a voltage drop across the body bias resistor, causing the body bias voltage to increase.

[0004] The increase in body-side bias voltage is proportional to the number of switching transistors connected in series. That is, the more switching transistors are connected in series, the more body-side bias resistance the terminal switching transistor's body leakage current will flow through, leading to a greater increase in body-side bias voltage. This increase in body-side bias voltage not only exacerbates switching nonlinearity but can also cause a rapid deterioration in harmonic performance. Furthermore, excessively high body-side bias voltage reduces the power handling capability of the switching transistor, making it more susceptible to breakdown, posing a serious threat to the reliability and stability of the RF switching circuit. Therefore, when designing RF switching circuits, special attention should be paid to these potential issues and appropriate measures should be taken to optimize circuit performance. Summary of the Invention

[0005] The primary technical problem to be solved by the present invention is to provide a radio frequency switching circuit for high power applications.

[0006] Another technical problem to be solved by the present invention is to provide an electronic device including the radio frequency switch circuit.

[0007] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0008] According to a first aspect of an embodiment of the present utility model, a radio frequency switching circuit for high power applications is provided, comprising a main circuit, a branch circuit and a feedback circuit; wherein,

[0009] The main circuit and the branch circuit have the same structure, both consisting of a stack of N switching transistors connected in series; the gate terminal of each switching transistor is connected to a gate bias resistor, the source terminal and the drain terminal are connected to a source-drain bias resistor, and the body terminal is connected to a body bias resistor;

[0010] The feedback circuit is composed of M diodes connected in series with the body terminal of each switching transistor in the main circuit and the branch circuit;

[0011] The body terminal of the Nth stage switching transistor in the main circuit is connected only to the source terminal of the N-Xth stage switching transistor and the drain terminal of the N+Xth stage switching transistor in the branch circuit through the diode in the feedback circuit; the body terminal of the Nth stage switching transistor in the branch circuit is connected only to the source terminal of the N-Xth stage switching transistor and the drain terminal of the N+Xth stage switching transistor in the main circuit through the diode in the feedback circuit;

[0012] M is a positive integer, N is a positive integer greater than or equal to 3, and X is a positive integer less than N.

[0013] According to a second aspect of the embodiments of the present utility model, an electronic device is provided, which includes the above-mentioned radio frequency switching circuit for high-power applications.

[0014] Compared with the prior art, the RF switching circuit provided by the embodiment of the present invention achieves excellent technical effects through its innovative cross-feedback structure, especially in terms of high power handling capacity and high harmonic processing capacity. Among them, the body-end connection diodes of the main circuit and the branch circuit are completely separated from the source and drain terminals of the switching transistors in their respective circuits, thereby fundamentally avoiding internal connections, effectively reducing the nonlinear effects caused by parasitic diodes, and thus reducing harmonic distortion. Therefore, the RF switching circuit provided by the embodiment of the present invention not only has high power handling capacity, can withstand large voltage fluctuations, and maintain the clarity and accuracy of communication signals; it also has high harmonic processing capabilities, can effectively reduce the harmonic interference caused by high-power signals, and meet the strict requirements of wireless communication systems for RF switching circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic wiring diagram of a radio frequency switch circuit for high-power applications in the first embodiment of the present utility model;

[0016] Figure 2 This is a schematic wiring diagram of a radio frequency switch circuit for high-power applications in the second embodiment of the present utility model;

[0017] Figure 3 This is a schematic wiring diagram of a radio frequency switch circuit for high-power applications in the third embodiment of the present utility model;

[0018] Figure 4 A comparison diagram of voltage simulation results at the source and drain terminals of the stacked switch transistors between the prior art and the first embodiment of the present invention;

[0019] Figure 5 A comparison chart of simulation results on second-order harmonics between the prior art and the first, second, and third embodiments of the present invention;

[0020] Figure 6 The figure is a schematic diagram of an electronic device using the radio frequency switch circuit provided by the utility model. DETAILED DESCRIPTION

[0021] The technical content of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] The RF switching circuit for high-power applications is mainly reflected in two aspects: high power handling capability, which can withstand high power fluctuations; high harmonic processing capability, which can effectively reduce the harmonic interference caused by high-power signals. Figure 1In the first embodiment shown, the radio frequency switching circuit is composed of at least a main circuit, a branch circuit, and a feedback circuit. The main circuit and the branch circuit have the same structure, both consisting of a plurality of switching transistors stacked in series. In the main circuit and the branch circuit, N-level switching transistors (N is a positive integer greater than or equal to 3) are arranged in series to form the core of the radio frequency switching circuit. Each switching transistor in the main circuit can form a one-to-one correspondence with each switching transistor in the branch circuit, that is, the Nth switching transistor in the main circuit has a unique corresponding relationship with the Nth switching transistor in the branch circuit, and vice versa.

[0023] Each switching transistor consists of a source terminal (S), a drain terminal (D), a gate terminal (G), and a body terminal (B). G , Rds and R B The gate bias resistor, source-drain bias resistor and body bias resistor are respectively corresponding to each switching transistor. In order to accurately control the working state of these switching transistors, three groups of bias networks are used in the embodiment of the utility model: the gate resistor bias network consists of N resistors R G The body resistor bias network consists of N resistors R B The source-drain resistor bias network, consisting of N resistors Rds, provides a stable bias voltage for the body of the switching transistor. The source-drain resistor bias network, consisting of N resistors Rds, manages the voltage between the source and drain terminals of the switching transistor. It should be noted that the main circuit and branch circuit have the same circuit structure, but the dimensions of the switching transistor (including but not limited to length, width, channel shape, etc.) can vary depending on application requirements.

[0024] In addition, the body terminal of the Nth switching transistor connected in series in the main circuit is connected to the source terminal or drain terminal of the switching transistor adjacent to the corresponding switching transistor (i.e., the Nth switching transistor) in the branch circuit through M (M is a positive integer, preferably 2) series-connected diodes, and the body terminal of the Nth switching transistor connected in series in the branch circuit is also connected to the source terminal or drain terminal of the switching transistor adjacent to the corresponding switching transistor (i.e., the Nth switching transistor) in the main circuit through M series-connected diodes. It should be noted that the adjacent here is not limited to the case of direct adjacent (i.e., N+1 and N-1), and may also include the case of indirect adjacent (i.e., N+2 and N-2, N+3 and N-3, ..., N+X and N-X, where X is a positive integer less than N).

[0025] exist Figure 1In the first embodiment shown, the cross-feedback structure in the RF switch circuit is an N+1 and N-1 (i.e., X=1) mode. Specifically, the body terminal B1 of the first-stage switching transistor in the main circuit is connected to the drain terminal D2 of the second-stage switching transistor in the branch circuit through two sets of M series-connected diodes connected in parallel. Similarly, the body terminal B1 of the Nth-stage switching transistor in the main circuit is connected to the drain terminal D2 of the second-stage switching transistor in the branch circuit. N It is also connected to the source terminal S of the N-1th stage switching transistor in the branch circuit through two sets of M series-connected diodes in parallel. N－1 The connection method for the body terminals of the first and Nth stage switching transistors in the branch circuit corresponds to that of the main circuit, using the same two-group parallel diode connection strategy. The number of diodes in series, M, is determined by the diode's breakover voltage and the voltage difference between the source and drain terminals of the switching transistor. The number of diodes in series in the main circuit and branch circuit can be the same or different, depending on different performance requirements.

[0026] The feedback circuit consists of M diodes connected in series with the body terminals of each switching transistor in the main circuit and branch circuits. The M diodes connected in series with the body terminals of each switching transistor in the feedback circuit cleverly achieve cross-connections between the main circuit and the branch circuits. Specifically, the body terminal of the Nth stage switching transistor in the main circuit is connected to the source terminal of the N-1th stage switching transistor and the drain terminal of the N+1th stage switching transistor in the branch circuit via M series diodes. This connection also exists between the third stage switching transistor in the main circuit and the second and fourth stage switching transistors in the branch circuit, and so on. Similarly, the body terminal of the Nth stage switching transistor in the branch circuit is also connected to the source terminal of the N-1th stage switching transistor and the drain terminal of the N+1th stage switching transistor in the main circuit via M series diodes. This connection also exists between the third stage switching transistor in the branch circuit and the second and fourth stage switching transistors in the main circuit, and so on.

[0027] exist Figure 2 In the second embodiment shown, the cross-feedback structure in the RF switch circuit is an N+2 and N-2 (i.e., X=2) mode. Specifically, the body terminal B1 of the first-stage switching transistor in the main circuit is connected to the drain terminal D3 of the third-stage switching transistor in the branch circuit through two sets of M series-connected diodes connected in parallel. Similarly, the body terminal B N It is also connected to the source terminal S of the N-2th stage switching transistor in the branch circuit through two sets of M series-connected diodes in parallel. N－2 The connection method of the body terminals of the 1st and Nth stage switching transistors in the branch circuit corresponds to that of the main circuit, and the same two sets of parallel diode connection strategy is also adopted.

[0028] The feedback circuit consists of M diodes connected in series with the body terminals of each switching transistor in the main circuit and the branch circuit. The body terminal of the Nth stage switching transistor in the main circuit is connected to the source terminal of the N-2th stage switching transistor and the drain terminal of the N+2th stage switching transistor in the branch circuit via M series diodes. This connection also exists between the third stage switching transistor in the main circuit and the first and fifth stage switching transistors in the branch circuit, and so on. Similarly, the body terminal of the Nth stage switching transistor in the branch circuit is also connected to the source terminal of the N-2th stage switching transistor and the drain terminal of the N+2th stage switching transistor in the main circuit via M series diodes. This connection also exists between the third stage switching transistor in the branch circuit and the first and fifth stage switching transistors in the main circuit, and so on.

[0029] exist Figure 3 In the third embodiment shown, the cross-feedback structure in the RF switch circuit is an N+3 and N-3 (i.e., X=3) mode. Specifically, the body terminal B1 of the first-stage switching transistor in the main circuit is connected to the drain terminal D4 of the fourth-stage switching transistor in the branch circuit through two sets of M series-connected diodes connected in parallel. Similarly, the body terminal B1 of the Nth-stage switching transistor in the main circuit is connected to the drain terminal D4 of the fourth-stage switching transistor in the branch circuit. N It is also connected to the source terminal S of the N-3th level switching transistor in the branch circuit through two sets of M series-connected diodes in parallel. N－3 The connection method of the body terminals of the 1st and Nth stage switching transistors in the branch circuit corresponds to that of the main circuit, and the same two sets of parallel diode connection strategy is also adopted.

[0030] The feedback circuit consists of M diodes connected in series with the body terminals of each switching transistor in the main circuit and the branch circuit. The body terminal of the Nth stage switching transistor in the main circuit is connected to the source terminal of the N-3th stage switching transistor and the drain terminal of the N+3th stage switching transistor in the branch circuit via M series diodes. This connection also exists between the 4th stage switching transistor in the main circuit and the 1st and 7th stage switching transistors in the branch circuit, and so on. Similarly, the body terminal of the Nth stage switching transistor in the branch circuit is also connected to the source terminal of the N-3th stage switching transistor and the drain terminal of the N+3th stage switching transistor in the main circuit via M series diodes. This connection also exists between the 4th stage switching transistor in the branch circuit and the 1st and 7th stage switching transistors in the main circuit, and so on.

[0031] It should be noted that the cross-feedback structure in the embodiments of the present invention is not limited to the above-mentioned embodiments. In fact, as long as X is a positive integer less than N, any connection method of N+X and N-X can be used to implement the above-mentioned cross-feedback structure.

[0032] In the aforementioned RF switching circuit for high-power applications, for the main circuit and branch circuits, excluding the first and last stages, the body terminal of each N-th stage switching transistor is connected solely to the source terminal of the N-1th stage switching transistor and the drain terminal of the N+1th stage switching transistor in the branch circuit, via a diode in the feedback circuit. Similarly, the body terminal of the N-th stage switching transistor in the branch circuit is also connected solely to the source terminal of the N-1th stage switching transistor and the drain terminal of the N+1th stage switching transistor in the main circuit, via a diode in the feedback circuit. This symmetrical connection strategy ensures efficient redistribution of current and voltage between the main circuit and the branch circuits, thereby improving the circuit's power handling and harmonic handling capabilities.

[0033] For both the first-stage main circuit and the branch circuit, the body terminal of the first-stage switching transistor in the main circuit is connected solely to the drain terminal of the second-stage switching transistor in the branch circuit via two parallel diodes. This parallel connection provides an additional path, helping to spread the voltage under high-power conditions and reduce voltage stress on individual diodes. The body terminal of the first-stage switching transistor in the branch circuit is also connected solely to the drain terminal of the second-stage switching transistor in the main circuit via diodes in the feedback circuit, maintaining the symmetry and balance of the circuit design.

[0034] For the final main and branch circuits, the body of the Nth-stage switching transistor in the main circuit is connected solely to the source of the N-1th-stage switching transistor in the branch circuit via two parallel diodes. This connection helps manage and control current and voltage at the final stage of the circuit, ensuring stability and reliability under high-power conditions. Similarly, the body of the Nth-stage switching transistor in the branch circuit is connected solely to the source of the N-1th-stage switching transistor in the main circuit via diodes in the feedback circuit, further enhancing circuit symmetry and balance.

[0035] In the above circuit design, the M series-connected diodes that form the feedback circuit can be replaced by M transistors configured in a diode-connected manner. This design allows the RF switching circuit to exhibit excellent power handling and harmonic processing capabilities under high power conditions.

[0036] On the other hand, the RF switch circuit design provided by the embodiment of the present invention fully considers the impact of parasitic diodes on circuit performance. In traditional RF switch circuits, parasitic diodes may be formed at the body end of each switching transistor. These parasitic diodes cause nonlinear effects in the circuit, especially when high-power signals appear. After in-depth research, the inventors confirmed that when the number of switching transistors in series is small, that is, N is less than 6, the nonlinear effects caused by these parasitic diodes are relatively small and can be ignored. However, as the number of switching transistors in series increases, that is, when N is greater than or equal to 6, the impact of the parasitic diodes becomes more significant, which may lead to a significant increase in the body end bias voltage, thereby exacerbating the nonlinear characteristics of the circuit. For this reason, the cross-feedback structure provided by the embodiment of the present invention is particularly suitable for cases where N is greater than or equal to 6. The cross-feedback structure can balance the body end bias voltage and reduce the adverse effects of the parasitic diodes through a carefully designed resistor bias network and diode connection method, as well as the appropriate arrangement of diodes in the main and branch circuits. This innovative cross-feedback structure effectively redistributes current and voltage between the main circuit and the branch circuit, improving the circuit's power handling capability while significantly reducing harmonic distortion caused by leakage current at the body end. Therefore, the RF switching circuit provided by the present invention can effectively manage and control harmonics caused by high-power signals and parasitic diodes.

[0037] It should be noted that in the RF switching circuit provided by the embodiment of the present invention, the diode connected to the body end of each switching transistor in the main circuit and the branch circuit is completely separated from the source end and drain end of the other switching transistors in their respective circuits. This circuit design ensures that the body end of each switching transistor in the main circuit is only connected to the source end or drain end of the corresponding switching transistor in the branch circuit through a diode, rather than to the source end or drain end of the main circuit itself. Similarly, the body end of each switching transistor in the branch circuit is also only connected to the source end or drain end of the corresponding switching transistor in the main circuit through a diode, rather than the source end and drain end of the switching transistor inside the branch circuit, thereby realizing a cross-connection between the two circuits. In the prior art, the body end diode of the switching transistor is connected to the source end or drain end of the switching transistor itself, which will cause an unnecessary increase in the body end bias voltage under high power conditions, affecting the power handling capacity and harmonic performance of the RF switching circuit. In the RF switching circuit provided by the embodiment of the present invention, by fundamentally avoiding such internal connection, the nonlinear effect caused by the parasitic diode is reduced, thereby optimizing the overall performance of the circuit.

[0038] In the radio frequency switching circuit provided by an embodiment of the present invention, the gate bias voltage and the body bias voltage of each switching transistor are set independently. Among them, the design of the common end of the gate and body bias resistors provides flexibility and freedom of adjustment. Specifically, the common end GC1 of the gate bias resistor of the main circuit and the common end BC1 of the body bias resistor, as well as the corresponding end points GC2 and BC2 of the branch circuit, can all set the bias voltage independently. This design allows precise voltage control of the main circuit and the branch circuit to adapt to different operating conditions and performance requirements. In addition, the common end of the gate and body bias resistors of the two circuits can also choose to use the same bias voltage, thereby simplifying the circuit design and power supply requirements.

[0039] The dimensions (particularly length and width) of the series switching transistors in the main and branch circuits can differ to accommodate the respective current and voltage requirements. The resistance values ​​of the resistor bias networks can also be independently selected based on design requirements. In particular, the width of the series switching transistors in the main circuit is typically designed to be greater than or equal to the width of the switching transistors in the branch circuits. This design choice helps manage parasitic effects caused by the different sizes of the switching transistors.

[0040] It should be noted that when the widths of the switching transistors used in the main circuit and branch circuits differ, this will cause the body leakage current to vary proportionally. Specifically, if the width of the switching transistors in the main circuit differs from that in the branch circuit, the body leakage current in the main circuit will also vary accordingly. To accommodate this variation and maintain circuit balance, the number of M diodes connected in series with the body terminals of the switching transistors in the feedback circuit is proportionally adjusted to ensure that they match the variation in body leakage current caused by the different transistor widths. This design allows the circuit to effectively manage and distribute body leakage current under various conditions, thereby maintaining circuit stability and performance. As the width of the switching transistors increases, the size of the parasitic switching transistors also increases. This increases body leakage current, which in turn causes a greater increase in the body bias voltage. To offset this increase, the body bias voltage needs to be set to a more negative value. This approach maintains switching transistor stability and circuit performance even under high-power operating conditions, reducing nonlinear distortion caused by body leakage current.

[0041] Therefore, the RF switching circuit provided by the present invention optimizes circuit performance through precise bias voltage control and switch transistor size selection. This circuit design not only improves the circuit's power handling capability but also helps reduce harmonic distortion, meeting the stringent requirements of high-performance communication systems for RF switching circuits.

[0042] In the RF switch circuit provided by the present invention, the signal transmission path (from RFin to RFout) in the on-state is specifically optimized. In this state, the M series diodes in the main and branch circuits are designed to minimize the impact on signal transmission. Because these diodes can be treated as open circuits in the on-state, their impact on the on-resistance is negligible. This design ensures that the optimization method does not negatively impact the performance of the signal in the on-state, thereby ensuring high efficiency and low loss in signal transmission.

[0043] When RF switching circuits are used for antenna impedance tuning, they typically need to be in the off state. In this off state, due to the internal structure of the switching transistors, a voltage difference will arise between the source and drain terminals of the stacked switching transistors. This voltage difference increases with increasing input power. When the voltage difference is small enough to cause the parasitic diodes to conduct, the body leakage current is low, and the series diodes can still be treated as open circuits, without affecting the circuit.

[0044] However, when the source-drain voltage difference increases to a certain level, exceeding a certain threshold, the parasitic diode will conduct, generating body-side leakage current. At this point, due to the large voltage difference between the source and drain terminals of the switching transistor, the series diode becomes a conductive low-resistance path. In this case, the body-side leakage current of the series-connected switching transistor in the main circuit will no longer flow through the body-side bias resistor, but will instead flow through the M series-connected diodes to the source or drain terminals of the adjacent switching transistors in the branch circuit. Similarly, the body-side leakage current in the branch circuit will also flow through the series-connected diodes to the source or drain terminals of the adjacent switching transistors in the main circuit.

[0045] This design cleverly leverages the conductive properties of diodes, offsetting the leakage current from the body via the source-drain bias resistor in the other branch, thus achieving balanced current distribution. This current management strategy effectively avoids the problems of reduced power handling capability and deterioration of harmonic performance caused by increased body-side bias voltage.

[0046] In the design of RF switching circuits, on-resistance is a key performance indicator. In the present invention, on-resistance can be optimized by finely controlling the size of the series switching transistors. Specifically, the length and width of the switching transistor directly affect its on-resistance and chip area. Shorter switching transistors can reduce on-resistance and chip area, but may have limitations in voltage resistance. This is because shorter switching transistors perform poorly in terms of voltage resistance and may not be able to withstand higher voltages. Therefore, a trade-off needs to be made between on-resistance and voltage resistance during design.

[0047] The value of the body-bias resistor also has a significant impact on circuit performance. A larger body-bias resistor increases the proportion of the body-leakage current flowing through the series diode, which helps reduce unnecessary increases in the body-bias voltage and thus reduces nonlinear distortion. However, this may come at the expense of increased switching transistor switching time, as the larger resistor increases the time it takes for the current to reach a steady state.

[0048] The widths of the switching transistors in both the main and branch circuits are carefully selected. Preferably, the width W1 of the switching transistor in the main circuit is greater than the width W2 of the switching transistor in the branch circuit. This design ensures that the bulk leakage current of the switching transistor in the main circuit is greater than that of the switching transistor in the branch circuit, helping to maintain the stability and performance of the RF switching circuit.

[0049] The RF switching circuit provided by the present invention achieves an optimal performance combination by adjusting the width and length of the switching transistors connected in series in the main circuit and branch circuits, as well as the resistance of the body-end bias resistor. This includes achieving the optimal on-resistance, the shortest switching time, and the smallest chip area. In addition, although the main circuit and branch circuits have the same structure, the size of the switching transistor and the number of series diodes can be adjusted according to different application requirements to meet specific performance requirements.

[0050] Figure 4 The figure shows the difference between the prior art and the first embodiment of the present invention in terms of the source-drain voltage (Vds) of the stacked switching transistors. In the simulation experiment, the same configuration scheme of 24 switching tubes in series was adopted, and the input power was set to 48dBm. The horizontal axis represents the source-drain voltage of the switching transistors from the first stage to the last stage, while the vertical axis shows the actual source-drain voltage value of each stage of the switching transistor, in volts (V). According to the data of the simulation experiment, the embodiment of the present invention exhibits a more uniform source-drain voltage distribution at all levels of the switching transistors. This uniform voltage distribution is crucial to ensuring the effective processing of high-power signals and reducing the risk of damage to the switching transistors, reflecting the significant advantages of the present invention in improving the performance of RF switching circuits.

[0051] Figure 5 The figure shows the difference between the prior art and the first, second and third embodiments in terms of second-order harmonic performance. Figure 5 It can be seen that in the low input power region, the second-order harmonic levels of the various embodiments of the present invention are roughly the same as those of the prior art. However, under high input power conditions, the various embodiments of the present invention demonstrate significant advantages, with the uniformity and continuity of the output signal significantly superior to the prior art.

[0052] Based on the above-mentioned RF switching circuit, an embodiment of the present invention further provides an integrated circuit chip, which includes the above-mentioned RF switching circuit for high-power applications. This integrated circuit chip is used as an important component of the RF front-end module in a wireless communication system. Its function is to accurately switch the transmission path of the RF signal and select the corresponding RF path. When the wireless communication system shares an antenna, it can realize the reception and transmission of RF signals. It can also be used for antenna impedance tuning to improve antenna efficiency. The specific structure of the RF switching circuit for high-power applications in this integrated circuit chip is not further described here.

[0053] In addition, the RF switching circuit for high-power applications provided by the present invention can be used in electronic devices as an important component of communication components. The electronic devices referred to here refer to computer devices that can be used in mobile environments and support multiple communication standards such as GSM, EDGE, CDMA, TD-SCDMA, WCDMA, TDD-LTE, FDD-LTE, NR, etc., including mobile phones, laptops, tablets, car computers, etc. In addition, the technical solution provided by the present invention is also applicable to other applications of RF integrated circuits, such as communication base stations and intelligent connected vehicles.

[0054] In one embodiment of the present invention, Figure 6 As shown, the electronic device includes at least a processor, a memory and a communication component, and may further include a sensor component, a power component, a multimedia component and an input / output interface according to actual needs. Among them, the memory, communication component, sensor component, power component, multimedia component and input / output interface are all connected to the processor. The memory can be a static random access memory (SRAM), an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a programmable read-only memory (PROM), a read-only memory (ROM), a magnetic memory, a flash memory, etc., and the processor can be a central processing unit (CPU), a graphics processing unit (GPU), a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a digital signal processing (DSP) chip, etc. Other communication components, sensor components, power components, multimedia components, etc. can all be implemented using general components and will not be described in detail here.

[0055] In summary, compared with the prior art, the RF switching circuit provided by the embodiment of the present invention achieves excellent technical effects through its innovative cross-feedback structure, especially in terms of high power handling capacity and high harmonic processing capacity. Among them, the body-end connection diodes of the main circuit and the branch circuit are completely separated from the source and drain terminals of the switching transistors in their respective circuits, thereby fundamentally avoiding internal connections, effectively reducing the nonlinear effects caused by parasitic diodes, and thus reducing harmonic distortion. Therefore, the RF switching circuit provided by the embodiment of the present invention not only has high power handling capacity, can withstand large voltage fluctuations, and maintain the clarity and accuracy of communication signals; it also has high harmonic processing capabilities, can effectively reduce the harmonic interference caused by high-power signals, and meet the strict requirements of wireless communication systems for RF switching circuits.

[0056] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0057] The above describes in detail the RF switch circuit, chip, and electronic device for high-power applications provided by this utility model. For those skilled in the art, any obvious modification to this utility model without departing from the essence of this utility model will constitute an infringement of the patent rights of this utility model and will result in corresponding legal liability.

Claims

1. A radio frequency switching circuit for high power applications, characterized in that It includes main circuit, branch circuit and feedback circuit; among them, The main circuit and the branch circuit have the same structure, both consisting of a stack of N switching transistors connected in series; the gate terminal of each switching transistor is connected to a gate bias resistor, the source terminal and the drain terminal are connected to a source-drain bias resistor, and the body terminal is connected to a body bias resistor; The feedback circuit is composed of M diodes connected in series with the body terminal of each switching transistor in the main circuit and the branch circuit; The body terminal of the Nth stage switching transistor in the main circuit is connected only to the source terminal of the N-Xth stage switching transistor and the drain terminal of the N+Xth stage switching transistor in the branch circuit through the diode in the feedback circuit; the body terminal of the Nth stage switching transistor in the branch circuit is connected only to the source terminal of the N-Xth stage switching transistor and the drain terminal of the N+Xth stage switching transistor in the main circuit through the diode in the feedback circuit; M is a positive integer, N is a positive integer greater than or equal to 3, and X is a positive integer less than N.

2. The radio frequency switching circuit according to claim 1, wherein: In the main circuit and branch circuit of the first stage, the body terminal of the first-stage switching transistor in the main circuit is connected only to the drain terminal of the second-stage switching transistor in the branch circuit through the diode in the feedback circuit; the body terminal of the first-stage switching transistor in the branch circuit is connected only to the drain terminal of the second-stage switching transistor in the main circuit through the diode in the feedback circuit.

3. The radio frequency switching circuit according to claim 1 or 2, wherein: In the main circuit and branch circuit of the last stage, the body end of the N-th stage switching transistor in the main circuit is connected only to the source end of the N-1-th stage switching transistor in the branch circuit through the diode in the feedback circuit; the body end of the N-th stage switching transistor in the branch circuit is connected only to the source end of the N-1-th stage switching transistor in the main circuit through the diode in the feedback circuit.

4. The radio frequency switching circuit according to claim 1, wherein: In the main circuit, the diode connected to the body terminal of each switching transistor is separated from the source terminal and the drain terminal of other switching transistors in the main circuit; and In the branch circuit, the diode connected to the body terminal of each switching transistor is separated from the source terminal and the drain terminal of other switching transistors in the branch circuit.

5. The radio frequency switching circuit according to claim 1, wherein: When the RF switching circuit is in the off state, the body leakage current of the switching transistor in the main circuit does not flow through the body bias resistor, but flows to the source or drain of the adjacent switching transistor in the branch circuit through the series diode; or, the body leakage current of the switching transistor in the branch circuit does not flow through the body bias resistor, but flows to the source or drain of the adjacent switching transistor in the main circuit through the series diode.

6. The radio frequency switching circuit according to claim 1, wherein: In the feedback circuit, the M series-connected diodes are replaced by M transistors in a diode-connected manner.

7. The radio frequency switching circuit according to claim 1, wherein: In the feedback circuit, the number of the M diodes connected in series with the body terminal of the switching transistor is adjusted according to the ratio of the width of the switching transistor in the main circuit to the width of the switching transistor in the branch circuit.

8. The radio frequency switch circuit according to claim 1, wherein: In the main circuit and the branch circuit, the gate bias voltage and the body bias voltage of each switching transistor are independently set.

9. The radio frequency switch circuit according to claim 1, wherein: The M is equal to 2, and the N is greater than or equal to 6.

10. An electronic device, characterized in that The invention comprises a radio frequency switching circuit for high power applications as described in any one of claims 1 to 9.

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