High-reliability radio frequency power amplifier power supply switching power supply device

Abstract

The invention provides a high-reliability radio frequency power amplifier power supply switching power supply device, and belongs to the technical field of wireless radio frequency communication, the device comprises a PMOS tube, an NMOS tube, a diode, an operational amplifier and four resistors, the resistor R1 and the diode are arranged between a G pole and an S pole of the PMOS tube in a parallel structure, the operational amplifier is arranged at a G pole port of the NMOS tube, and the resistor R2 is arranged at an S pole port of the NMOS tube. The resistor R3 is arranged between the PMOS tube and the NMOS tube, the resistor R2 is arranged between the inverting input end of the operational amplifier and the ground, the resistor R4 is arranged between the inverting input end of the operational amplifier and the G pole of the NMOS tube, and a PTT signal passes through the operational amplifier and controls the on and off of the PMOS tube and the NMOS tube, so that the input voltage VIN enters the radio frequency power amplifier to control the working state of the radio frequency power amplifier. According to the scheme, the operational amplifier and the diode are additionally arranged in the power supply device, so that the reliability and the stability of the radio frequency power amplifier switching power supply device are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency communication, and in particular to a high-reliability radio frequency power amplifier power supply switching power supply device. Background Art

[0002] With the development of radio frequency communication technology, frequency resources are becoming increasingly scarce, and civilian and military frequencies overlap and interfere with each other. More and more communication devices adopt TDD (Time Division Duplex) communication technology, which works by receiving and transmitting at different times on the same frequency, thus greatly saving frequency resources.

[0003] When using TDD communication technology, the power supply of the radio frequency power amplifier of the communication device needs to be controlled. It is required that the radio frequency power amplifier power supply is turned on during signal transmission and turned off during signal reception. Since TDD (Time Division Duplex) communication technology is used, during communication, the power supply switching power supply of the radio frequency power amplifier switches frequently between on and off, which requires the radio frequency power amplifier power supply switching power supply device to have extremely high reliability and is not easily burned out.

[0004] Currently, the existing radio frequency power amplifier power supply switching power supply devices usually use a single PMOS and NMOS transistor to build, without protecting the MOS transistors. They are extremely easy to burn out when encountering unstable power supply; at the same time, there are no buffering and isolation measures for the PTT control signal. When encountering unstable PTT control signals, it is extremely easy to cause the PMOS and NMOS transistors to work abnormally, resulting in instability of the switching power supply circuit. Summary of the Invention

[0005] In response to the above problems, the present invention proposes a high-reliability RF power amplifier power supply switching power supply device, which includes: a PMOS tube, an NMOS tube, a diode, an operational amplifier and four resistors. The resistor R1 and the diode are placed in parallel between the G pole and the S pole of the PMOS tube. One end of the resistor R1 is connected to the S pole of the PMOS tube and is also connected to the power supply voltage VIN. The other end of the resistor R1 is connected to the G pole of the PMOS tube and is also connected to one end of the resistor R3. One end of the diode is connected to the S pole of the PMOS tube and is also connected to the power supply voltage VIN. The other end of the diode is connected to the G pole of the PMOS tube and is also connected to one end of the resistor R3. One end of the resistor R3 is also connected to the G pole of the PMOS tube, the other end of the resistor R3 is connected to the S pole of the NMOS tube, the D pole of the PMOS tube is connected to the external RF power amplifier, the G pole of the NMOS tube is connected to the output end of the operational amplifier, and is also connected to one end of the resistor R4, the D pole of the NMOS tube is grounded, one end of the resistor R4 is also connected to the output end of the operational amplifier, the other end of the resistor R4 is connected to one end of the resistor R2, the other end of the resistor R4 is also connected to the inverting input end of the operational amplifier, the inverting input end of the operational amplifier is also connected to one end of the resistor R2, the other end of the resistor R2 is grounded, and the non-inverting input end of the operational amplifier is connected to the control signal PTT.

[0006] Furthermore, the resistors R2 and R4 connected to the inverting input terminal and the output terminal of the operational amplifier have the same resistance value and form a voltage follower with the operational amplifier to isolate and buffer the PTT control signal.

[0007] Furthermore, the reverse breakdown voltage of the diode connected between the G pole and the S pole of the PMOS tube is less than the maximum voltage that the gate and source of the PMOS tube can withstand.

[0008] Furthermore, when the RF power amplifier needs to work normally, the PTT control signal is at a high level. After passing through the operational amplifier, the G pole of the NMOS tube is at a high level, thereby creating a voltage difference between its G pole and S pole, causing the NMOS tube to be turned on. When the NMOS tube is turned on, the power supply voltage VIN is divided by R1 and R3, creating a voltage difference between the G pole and S pole of the PMOS tube, thereby turning on the PMOS tube. At this time, the power supply voltage VIN is supplied to the RF power amplifier through the PMOS tube output voltage VOUT, and the RF power amplifier is working.

[0009] Furthermore, when the PTT control signal is at a low level, the operational amplifier causes the G pole of the NMOS tube to be at a low level, and there is no voltage difference between the G pole and the S pole. At this time, the NMOS tube is cut off, thereby causing the PMOS tube to be cut off as well. The power supply voltage VIN cannot pass through the PMOS tube output voltage to power the RF power amplifier, and the RF power amplifier stops working.

[0010] The present invention provides a high-reliability switching power supply device for a radio frequency power amplifier. In this power supply device, an operational amplifier is added, and resistors R2 and R4 are connected to the inverting input terminal and the output terminal thereof, and the resistance values of the two resistors are the same, thereby forming a voltage follower, which plays an isolation and buffering role for the PTT control signal, making the control signal level entering the backend stable, so that the PMOS transistor and the NMOS transistor work normally and stably, improving the reliability of the switching power supply device for the radio frequency power amplifier; meanwhile, a diode is connected between the gate (G pole) and the source (S pole) of the PMOS transistor, and the reverse breakdown voltage of the diode is less than the maximum voltage that can be borne between the gate and the source of the PMOS transistor. Usually, the instantaneous voltage of the power supply for powering the power amplifier is relatively high, especially when the power supply is just started. When the instantaneous voltage of the power supply voltage VIN is too high and exceeds the maximum voltage that can be borne by the gate and the source of the PMOS transistor, at this time, the diode breaks down reversely first (the diode has restorability), so that the voltage across the diode is maintained at a fixed value (this voltage value is less than the maximum voltage that can be borne by the gate and the source of the PMOS transistor), thereby protecting the PMOS transistor from being burned out by the instantaneous high voltage of the power supply and improving the reliability of the switching power supply device for the radio frequency power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0012] Figure 1 FIG. is a schematic structural diagram of a high-reliability switching power supply device for a radio frequency power amplifier provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0014] The present invention provides a high-reliability switching power supply device for a radio frequency power amplifier, as Figure 1As shown, the device includes: a PMOS transistor, an NMOS transistor, a diode, an operational amplifier, and four resistors. Resistor R1 and the diode are placed in a parallel structure between the G and S poles of the PMOS transistor. One end of resistor R1 is connected to the S pole of the PMOS transistor and also to the power supply voltage VIN. The other end of resistor R1 is connected to the G pole of the PMOS transistor and also to one end of resistor R3. One end of the diode is connected to the S pole of the PMOS transistor and also to the power supply voltage VIN. The other end of the diode is connected to the G pole of the PMOS transistor and also to one end of resistor R3. One end of resistor R3 is also connected to the G pole of the PMOS transistor. The other end of resistor R3 is connected to the S pole of the NMOS transistor. The D pole of the PMOS transistor is connected to an external radio frequency power amplifier. The G pole of the NMOS transistor is connected to the output terminal of the operational amplifier and also to one end of resistor R4. The D pole of the NMOS transistor is grounded. One end of resistor R4 is also connected to the output terminal of the operational amplifier. The other end of resistor R4 is connected to one end of resistor R2. The other end of resistor R4 is also connected to the inverting input terminal of the operational amplifier. The inverting input terminal of the operational amplifier is also connected to one end of resistor R2. The other end of resistor R2 is grounded. The non-inverting input terminal of the operational amplifier is connected to the control signal PTT.

[0015] In this circuit, an operational amplifier is added, and resistors R2 and R4 are connected to its inverting input terminal and output terminal respectively, and the two resistors have the same resistance value, thus forming a voltage follower, which plays an isolation and buffering role for the PTT control signal, making the control signal level entering the backend stable, so that the PMOS transistor and the NMOS transistor work normally and stably, improving the reliability of the radio frequency power amplifier power supply switching power supply device.

[0016] A diode is connected between the gate (G pole) and source (S pole) of the PMOS transistor. The reverse breakdown voltage of the diode is less than the maximum voltage that can be borne between the gate and source of the PMOS transistor. Usually, the instantaneous voltage of the power supply for the power amplifier is relatively high, especially when the power supply is just started. When the instantaneous voltage of the power supply voltage VIN is too high and exceeds the maximum voltage that the gate and source of the PMOS transistor can bear, at this time, the diode breaks down reversely first (the diode has restorability), making the voltage across the diode maintain a fixed value (this voltage value is less than the maximum voltage that the gate and source of the PMOS transistor can bear), thereby protecting the PMOS transistor from being burned out by the instantaneous high voltage of the power supply and improving the reliability of the radio frequency power amplifier power supply switching power supply device.

[0017] In the specific implementation, the PTT control signal is set to a high level of 3.3V, and the resistance values of resistors R1, R2, R3, and R4 are all 1K ohms. After passing through the operational amplifier, it enters the NMOS tube and is a stable 3.3V high level. If the PTT signal has ripples or glitches or the driving capability is insufficient, the voltage follower circuit composed of the operational amplifier, R2, and R4 will output a stable PTT signal, thereby turning on the NMOS tube and then the PMOS tube. At this time, the power supply VIN is 28V, and the power supply outputs VOUT through the PMOS tube to power the RF power amplifier, and the RF power amplifier works.

[0018] When the PTT control signal is at a low level of 0V, the resistance values of resistors R1, R2, R3, and R4 are all 1K ohms. After passing through the operational amplifier and entering the NMOS tube, a stable low level of 0V is output, thereby turning off the NMOS tube and then the PMOS tube. At this time, the power supply VIN is 28V, and the power supply cannot output VOUT through the PMOS tube to power the RF power amplifier, and the RF power amplifier stops working.

[0019] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-reliability RF power amplifier power supply switching power supply device, characterized in that, The device includes a PMOS transistor, an NMOS transistor, a diode, an operational amplifier, and four resistors. Resistor R1 and the diode are placed in a parallel structure between the G and S poles of the PMOS transistor. One end of resistor R1 is connected to the S pole of the PMOS transistor and also to the power supply voltage VIN. The other end of resistor R1 is connected to the G pole of the PMOS transistor and also to one end of resistor R3. One end of the diode is connected to the S pole of the PMOS transistor and also to the power supply voltage VIN. The other end of the diode is connected to the G pole of the PMOS transistor and also to one end of resistor R3. One end of resistor R3 is also connected to the G pole of the PMOS transistor. The other end of resistor R3 is connected to the S pole of the NMOS transistor. The D pole of the PMOS transistor is connected to an external RF power amplifier. The G pole of the NMOS transistor is connected to the output terminal of the operational amplifier and also to one end of resistor R4. The D pole of the NMOS transistor is grounded. One end of resistor R4 is also connected to the output terminal of the operational amplifier. The other end of resistor R4 is connected to one end of resistor R2. The other end of resistor R4 is also connected to the inverting input terminal of the operational amplifier. The inverting input terminal of the operational amplifier is also connected to one end of resistor R2. The other end of resistor R2 is grounded. The non-inverting input terminal of the operational amplifier is connected to the control signal PTT.

2. The device according to claim 1, wherein The resistors R2 and R4 connected between the inverting input terminal and the output terminal of the operational amplifier have the same resistance value and form a voltage follower with the operational amplifier, which plays an isolation and buffering role for the PTT control signal.

3. The device according to claim 1, characterized in that, The reverse breakdown voltage of the diode connected between the G and S poles of the PMOS transistor is less than the maximum voltage that can be borne between the gate and source of the PMOS transistor.

4. The device according to claim 1, characterized in that, When the RF power amplifier needs to work properly, the PTT control signal is at a high level. After passing through the operational amplifier, the G pole of the NMOS transistor is at a high level, so that there is a voltage difference between its G and S poles and the NMOS transistor conducts. When the NMOS transistor conducts, after the power supply voltage VIN is divided by R1 and R3, there is a voltage difference between the G and S poles of the PMOS transistor, so that the PMOS transistor conducts. At this time, the power supply voltage VIN outputs the voltage VOUT through the PMOS transistor to supply power to the RF power amplifier, and the RF power amplifier works at this time.

5. The device according to claim 4, characterized in that, When the PTT control signal is at a low level, after passing through the operational amplifier, the G pole of the NMOS transistor is at a low level, and there is no voltage difference between the G and S poles. At this time, the NMOS transistor is cut off, so that the PMOS transistor is also cut off, and the power supply voltage VIN cannot output voltage through the PMOS transistor to supply power to the RF power amplifier, and the RF power amplifier stops working.

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