Radio frequency switch circuit and radio frequency chip

Abstract

The application provides a radio frequency switch circuit and a radio frequency chip, and the radio frequency switch circuit comprises a switch module, a gate voltage control module and a body voltage control module, wherein the switch module comprises a radio frequency switch transistor, the source of the radio frequency switch transistor and the drain of the radio frequency switch transistor are connected to each other to form a signal channel; the gate voltage control module is used for connecting the gate of the radio frequency switch transistor and providing an operating voltage for the radio frequency switch transistor; the body voltage control module is connected to the body of the radio frequency switch transistor and the gate of the radio frequency switch transistor respectively, and is used for dynamically adjusting the potential of the body of the radio frequency switch transistor according to the size of the operating voltage received by the gate of the radio frequency switch transistor. The application can effectively control the on-resistance and off-capacitance of the radio frequency switch circuit, thereby effectively improving the performance of the radio frequency switch.

Description

Technical Field

[0001] This invention relates to the field of radio frequency circuit technology, and particularly to a radio frequency switch circuit and a radio frequency chip. Background Technology

[0002] In modern communication systems, radio frequency (RF) switches are indispensable core components, widely used in various RF communication devices. With the continuous iteration of communication technology, the market's requirements for the RF performance of RF switches are constantly increasing. The core performance indicators of RF switches include insertion loss, isolation, harmonic characteristics, and power tolerance; each indicator directly determines the signal transmission quality and operational stability of communication equipment. Research has shown that the on-resistance R of an RF switch... on With the turn-off capacitor C off These are the key parameters affecting the above performance indicators. Optimizing these two parameters and balancing the electrical characteristics is the core research and development direction for improving the overall performance of RF switches.

[0003] Currently, mainstream RF switches use transistor circuit structures. To ensure the stability of switch operation, existing technologies employ a fixed wiring design for RF switch transistors. Specifically, a current-limiting resistor is connected in series at the gate of the transistor, a conduction path is formed between the source and drain through a series on-resistor, and a bias resistor is connected to the back gate. This circuit structure is simple, compatible with conventional manufacturing processes, and is a common and traditional design scheme for RF switch transistors of the same size, widely used in various conventional RF switch products.

[0004] However, existing traditional circuit designs still have significant technical shortcomings. Given the same RF switch transistor size, the turn-off capacitor in traditional structures is too large. This excessively large turn-off capacitor directly degrades core performance indicators of the RF switch, such as isolation and insertion loss, while also reducing harmonic suppression and power handling capabilities. Furthermore, this structure struggles to achieve synergistic optimization of on-resistance and turn-off capacitor, resulting in poor parameter balancing and limiting the overall electrical performance of the RF switch. This makes it unsuitable for the high-frequency, high-precision applications of modern communication, hindering the overall performance upgrade and optimization of communication equipment. Summary of the Invention

[0005] This invention provides an RF switch circuit and an RF chip, aiming to solve the technical problem that existing RF switch circuits are difficult to optimize by balancing on-resistance and off-resistance.

[0006] To address the aforementioned technical problems, in a first aspect, the present invention provides a radio frequency switching circuit, comprising a switching module, a gate voltage control module, and a body voltage control module, wherein:

[0007] The switching module includes a radio frequency (RF) switching transistor. The source and drain of the RF switching transistor are connected to each other to form a signal path. The drain of the RF switching transistor serves as the signal input terminal of the RF switching circuit, and the source of the RF switching transistor serves as the signal output terminal of the RF switching circuit. The gate voltage control module is connected to the gate of the radio frequency switching transistor and provides it with an operating voltage; The body voltage control module is connected to the body of the radio frequency switching transistor and the gate of the radio frequency switching transistor, respectively, and is used to dynamically adjust the potential of the body of the radio frequency switching transistor according to the magnitude of the operating voltage received by the gate of the radio frequency switching transistor. The body voltage control module includes a diode array, a first control transistor, and a second control transistor, wherein: The diode array includes multiple diodes connected in series, with the positive terminal of the first diode serving as the first electrode of the diode array and the negative terminal of the last diode serving as the second electrode of the diode array. The source of the first control transistor is connected to the body of the radio frequency switching transistor, the drain of the first control transistor is connected to the second terminal of the diode array, and the gate of the first control transistor is connected to the first terminal of the diode array. The source of the second control transistor is connected to the second terminal of the diode array, the drain of the second control transistor is connected to the first terminal of the diode array, and the gate of the second control transistor is connected to the body of the radio frequency switching transistor. The second electrode of the diode array is connected to the gate of the radio frequency switching transistor.

[0008] Furthermore, the switching module also includes a bridging resistor, the two ends of which are connected to the source and drain of the radio frequency switching transistor, respectively.

[0009] Furthermore, the gate voltage control module includes a gate resistor, the first end of which is connected to the gate of the RF switching transistor, and the second end of which is used to connect to the operating voltage.

[0010] Furthermore, the body voltage control module also includes a clamping diode, which is connected in series between the source of the second control transistor and the second terminal of the diode array, with the positive terminal of the clamping diode connected to the source of the second control transistor and the negative terminal of the clamping diode connected to the second terminal of the diode array.

[0011] Furthermore, when the gate voltage of the radio frequency switch crystal is positive, the radio frequency switch transistor is turned on, and the first control transistor, the second control transistor, and the diode array are all turned off. When the gate voltage of the radio frequency switch crystal is negative, the radio frequency switch transistor is turned off, and the first control transistor, the second control transistor, and the diode array are all turned on.

[0012] Furthermore, when the operating voltage provided by the gate voltage control module is a positive voltage, the clamping diode is turned off; when the operating voltage provided by the gate voltage control module is a negative voltage, the clamping diode is turned on.

[0013] Secondly, the present invention also provides a radio frequency chip, the radio frequency chip including the radio frequency switching circuit described above.

[0014] The beneficial effects achieved by this invention lie in proposing a radio frequency (RF) switch circuit. This circuit dynamically adjusts the body potential of the RF switch transistor by setting up a gate voltage control module and a body voltage control module, and utilizing the cooperation of a diode array, clamping diodes, and control transistors. When the switch is on, the body is in a floating or slightly positive potential, effectively reducing the on-resistance and insertion loss. When the switch is off, the body is clamped to a negative potential, significantly reducing the off-capacity and improving the isolation, thereby effectively improving the performance of the RF switch. Attached Figure Description

[0015] The present invention will now be described in detail with reference to the accompanying drawings. The above and other aspects of the present invention will become clearer and more readily understood through the detailed description following the accompanying drawings. In the drawings: Figure 1 This is a circuit diagram of the radio frequency switch circuit provided in an embodiment of the present invention; Figure 2 This is a circuit diagram of another radio frequency switch circuit provided in an embodiment of the present invention. Detailed Implementation

[0016] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] The specific embodiments / examples described herein are specific implementations of the present invention, used to illustrate the concept of the invention, and are illustrative and exemplary, and should not be construed as limiting the implementation methods or scope of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein, all of which are within the protection scope of the present invention.

[0018] Example 1 Please refer to Figure 1 , Figure 1 This is a circuit diagram of a radio frequency (RF) switch circuit 100 provided in an embodiment of the present invention. The RF switch circuit 100 includes a switch module 101, a gate voltage control module 102, and a body voltage control module 103, wherein: The switching module 101 includes a radio frequency switching transistor MOS. The source and drain of the radio frequency switching transistor MOS are connected to each other to form a signal path. The drain of the radio frequency switching transistor MOS serves as the signal input terminal RFin of the radio frequency switching circuit 100, and the source of the radio frequency switching transistor MOS serves as the signal output terminal RFout of the radio frequency switching circuit 100. The gate voltage control module 102 is connected to the gate of the radio frequency switching transistor MOS and connected to the operating voltage VG to provide it with the operating voltage; The body voltage control module 103 is connected to the body of the RF switching transistor MOS and the gate of the RF switching transistor MOS, respectively, and is used to dynamically adjust the potential of the body of the RF switching transistor MOS according to the magnitude of the operating voltage VG received by the gate of the RF switching transistor MOS.

[0019] Specifically, such as Figure 1 As shown, in this embodiment of the invention, the body voltage control module 103 includes a diode array D1~Dn, a first control transistor M1, and a second control transistor M2, wherein: The diode array D1~Dn includes multiple diodes connected in series, with the positive terminal of the first diode D1 serving as the first terminal of the diode array D1~Dn, and the negative terminal of the last diode Dn serving as the second terminal of the diode array D1~Dn. The source of the first control transistor M1 is connected to the body of the radio frequency switching transistor MOS, the drain of the first control transistor M1 is connected to the second terminal of the diode array D1~Dn, and the gate of the first control transistor M1 is connected to the first terminal of the diode array D1~Dn. The source of the second control transistor M2 is connected to the second terminal of the diode array D1~Dn, the drain of the second control transistor M2 is connected to the first terminal of the diode array D1~Dn, and the gate of the second control transistor M2 is connected to the body of the RF switching transistor MOS. The second electrode of the diode array D1~Dn is connected to the gate of the RF switching transistor MOS.

[0020] In this embodiment of the invention, the first control transistor M1 is a PMOS transistor, and the second control transistor M2 is an NMOS transistor.

[0021] The switching module 101 further includes a bridging resistor RDS, the two ends of which are connected to the source and drain of the radio frequency switching transistor MOS, respectively.

[0022] The gate voltage control module 102 includes a gate resistor RG. The first end of the gate resistor RG is connected to the gate of the radio frequency switching transistor MOS, and the second end of the gate resistor RG is used to connect to the operating voltage VG.

[0023] The working principle of the radio frequency switch circuit 100 provided in the embodiments of the present invention will be explained in detail below. In the embodiments of the present invention, when the gate operating voltage VG of the radio frequency switch transistor MOS is a positive voltage, the radio frequency switch transistor MOS is turned on, and the first control transistor M1, the second control transistor M2 and the diode array D1~Dn are all turned off; When the gate operating voltage VG of the RF switching transistor MOS is negative, the RF switching transistor MOS is turned off, and the first control transistor M1, the second control transistor M2, and the diode arrays D1~Dn are all turned on.

[0024] Specifically, in this embodiment of the invention, the gate voltage control module 102 provides the operating voltage VG to the radio frequency switching transistor MOS, while the body voltage control module 103 dynamically adjusts the body potential of the radio frequency switching transistor MOS according to the gate voltage VG.

[0025] When the gate voltage VG of the RF switching transistor MOS is positive, the gate potential of the RF switching transistor MOS is higher than the source-drain potential, and the RF switching transistor MOS is turned on. The RF signal can be transmitted through the signal path formed by its source, drain, and the bridging resistor RDS. At this time, the first control transistor M1 and the second control transistor M2 are turned off due to insufficient gate-source voltage, and the diode array D1~Dn is also turned off due to reverse voltage. The body voltage control module 103 is in an open state, and the body of the RF switching transistor MOS is floating or at a small positive potential, effectively reducing the on-resistance and insertion loss.

[0026] When the gate operating voltage VG of the RF switching transistor MOS is negative, the gate potential of the RF switching transistor MOS is lower than the source-drain potential, the RF switching transistor MOS is turned off, and the RF signal path is cut off. At this time, the first control transistor M1 and the second control transistor M2 meet the conduction conditions and are turned on, and the diode array D1~Dn are all subjected to a positive voltage and are turned on; the body voltage control module 103 forms a low-resistance path, clamping the body of the RF switching transistor MOS to a potential close to the negative voltage, making the turn-off more thorough, significantly reducing the turn-off capacitance, and improving the isolation.

[0027] Example 2 Furthermore, please refer to Figure 2 , Figure 2 This is a circuit diagram of another radio frequency switch circuit provided in an embodiment of the present invention, compared to... Figure 1 The circuit structure shown includes a body voltage control module 103 that further includes a clamping diode Ds. The clamping diode Ds is connected in series between the source of the second control transistor M2 and the second electrode of the diode array D1~Dn. The positive electrode of the clamping diode Ds is connected to the source of the second control transistor M2, and the negative electrode of the clamping diode Ds is connected to the second electrode of the diode array D1~Dn.

[0028] When the operating voltage VG provided by the gate voltage control module 102 is a positive voltage, the clamping diode Ds is turned off; when the operating voltage VG provided by the gate voltage control module 102 is a negative voltage, the clamping diode Ds is turned on.

[0029] Specifically, when the gate operating voltage VG of the RF switching transistor MOS is positive, the RF switching transistor MOS is in the on state, and the first control transistor M1, the second control transistor M2, and the diode arrays D1~Dn are all turned off. At this time, the clamping diode Ds is turned off due to the reverse voltage across it. Its off state can further isolate the potential coupling between the source of the second control transistor M2 and the second electrode of the diode arrays D1~Dn, avoid the body potential being affected by stray signals, ensure that the body of the RF switching transistor MOS is stably maintained in a floating or slightly positive potential state, and guarantee low on-resistance characteristics.

[0030] When the gate operating voltage VG of the RF switching transistor MOS is negative, the RF switching transistor MOS is in the off state, and the first control transistor M1, the second control transistor M2, and the diode arrays D1~Dn are all turned on. At this time, the clamping diode Ds is forward-biased and turns on, forming a low-resistance path between the source of the second control transistor M2 and the second electrode of the diode arrays D1~Dn. This enhances the clamping effect of the body potential, stably pulling the body of the RF switching transistor MOS to a potential close to negative, further reducing its turn-off capacitance and improving the isolation and turn-off performance of the RF switch.

[0031] Overall, compared to Figure 1 The circuit structure shown, through the additional clamping diode Ds, is turned off under positive voltage to isolate the circuit node, which enables the body of the RF switching transistor MOS to float more thoroughly, reducing on-resistance and insertion loss; while under negative voltage, it is turned on to further enhance the negative voltage clamping effect of the body, reduce the turn-off capacitance and improve isolation, stabilize the body potential, and optimize the core performance of the RF switch.

[0032] The beneficial effects achieved by this invention lie in proposing a radio frequency (RF) switch circuit. This circuit dynamically adjusts the body potential of the RF switch transistor by setting up a gate voltage control module and a body voltage control module, and utilizing the cooperation of a diode array, clamping diodes, and control transistors. When the switch is on, the body is in a floating or slightly positive potential, effectively reducing the on-resistance and insertion loss. When the switch is off, the body is clamped to a negative potential, significantly reducing the off-capacity and improving the isolation, thereby effectively improving the performance of the RF switch.

[0033] Example 3 This invention also provides an RF chip, which includes the RF switch circuit 100 described in Embodiment 1 or 2 above. It is understood that, based on the specific circuit design of the RF switch circuit 100, the RF chip can dynamically adjust the body potential of the RF switch transistor by utilizing a diode array, clamping diodes, and control transistors. When the switch is on, the body is in a floating or slightly positive potential, effectively reducing on-resistance and insertion loss. When the switch is off, the body is clamped to a negative potential, significantly reducing the off-capacitance, improving isolation, and overall optimizing the core performance of the RF switch. Referring to the descriptions in the above embodiments, further details are omitted here.

[0034] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0035] The embodiments of the present invention have been described above with reference to the accompanying drawings. The disclosed embodiments are merely preferred embodiments of the present invention. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many equivalent changes in form under the guidance of the present invention without departing from the spirit and scope of the claims. All such changes are within the protection scope of the present invention.

Claims

1. A radio frequency switching circuit, characterized in that, It includes a switching module, a gate voltage control module, and a body voltage control module, wherein: The switching module includes a radio frequency (RF) switching transistor. The source and drain of the RF switching transistor are connected to each other to form a signal path. The drain of the RF switching transistor serves as the signal input terminal of the RF switching circuit, and the source of the RF switching transistor serves as the signal output terminal of the RF switching circuit. The gate voltage control module is connected to the gate of the radio frequency switching transistor and provides it with an operating voltage; The body voltage control module is connected to the body of the radio frequency switching transistor and the gate of the radio frequency switching transistor, respectively, and is used to dynamically adjust the potential of the body of the radio frequency switching transistor according to the magnitude of the operating voltage received by the gate of the radio frequency switching transistor. The body voltage control module includes a diode array, a first control transistor, and a second control transistor, wherein: The diode array includes multiple diodes connected in series, with the positive terminal of the first diode serving as the first electrode of the diode array and the negative terminal of the last diode serving as the second electrode of the diode array. The source of the first control transistor is connected to the body of the radio frequency switching transistor, the drain of the first control transistor is connected to the second terminal of the diode array, and the gate of the first control transistor is connected to the first terminal of the diode array. The source of the second control transistor is connected to the second terminal of the diode array, the drain of the second control transistor is connected to the first terminal of the diode array, and the gate of the second control transistor is connected to the body of the radio frequency switching transistor. The second electrode of the diode array is connected to the gate of the radio frequency switching transistor.

2. The radio frequency switching circuit according to claim 1, characterized in that, The switching module also includes a bridging resistor, the two ends of which are connected to the source and drain of the radio frequency switching transistor, respectively.

3. The radio frequency switching circuit according to claim 1, characterized in that, The gate voltage control module includes a gate resistor, the first end of which is connected to the gate of the radio frequency switching transistor, and the second end of which is used to connect to the operating voltage.

4. The radio frequency switching circuit according to claim 1, characterized in that, The body voltage control module further includes a clamping diode, which is connected in series between the source of the second control transistor and the second terminal of the diode array. The positive terminal of the clamping diode is connected to the source of the second control transistor, and the negative terminal of the clamping diode is connected to the second terminal of the diode array.

5. The radio frequency switching circuit according to claim 1, characterized in that, When the gate voltage of the radio frequency switching transistor is positive, the radio frequency switching transistor is turned on, and the first control transistor, the second control transistor, and the diode array are all turned off. When the gate voltage of the radio frequency switching transistor is negative, the radio frequency switching transistor is turned off, and the first control transistor, the second control transistor, and the diode array are all turned on.

6. The radio frequency switching circuit according to claim 4, characterized in that, When the operating voltage provided by the gate voltage control module is a positive voltage, the clamping diode is turned off; when the operating voltage provided by the gate voltage control module is a negative voltage, the clamping diode is turned on.

7. A radio frequency chip, characterized in that, The radio frequency chip includes the radio frequency switching circuit as described in any one of claims 1 to 6.

Images