Static operating point temperature compensation circuit for high-efficiency MOS tube power amplifier

Abstract

The invention discloses a static operating point temperature compensation circuit for a high-efficiency MOS tube power amplifier, comprising: a temperature sensing compensation bias circuit and an isolated output circuit; the invention aims at the high-efficiency special application requirements, that is, in the case of strictly limiting the power consumption of the amplifier and large changes in the temperature of the use environment, by using the temperature change characteristics of the static voltage of a triode and a FET field effect tube to perform compensation amplification, and using an integrated operational amplifier for isolated output, a variable static operating point voltage with temperature compensation is provided to the MOS field effect tube, so as to realize the compensation control of the output power when the temperature changes, and reduce the adverse effects of the deep ALC loop control.

Description

Technical Field

[0001] The invention belongs to the technical field of communication equipment, and in particular relates to a static operating point temperature compensation circuit of a high-efficiency MOS tube power amplifier. Background Art

[0002] The power amplifier is an important component of communication equipment. Its main requirement is generally that its output power should fluctuate within a certain range when the ambient temperature changes. At the same time, in special applications, the conversion efficiency of its power supply is also an evaluation indicator.

[0003] The static operating point of the MOS tube power amplifier is generally set to a constant voltage. Under different temperature conditions, the static operating current of the power amplifier tube will change with the temperature, and its output power will also fluctuate greatly. Therefore, its output power generally adopts the closed-loop control method of automatic level control ALC (Automatic Level Control). Specifically, by detecting the output power signal, the total attenuation (amplification) of the variable attenuator (amplifier) ​​of its amplification link is adjusted to reduce the output power of the amplifier. The principle block diagram is shown in Figure 1 This method can meet most of the usage requirements. However, when the amplifier power consumption is strictly limited and the ambient temperature changes greatly, the depth of the ALC loop control will increase, which will inevitably have an adverse effect on the power conversion efficiency. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a static operating point temperature compensation circuit for a high-efficiency MOS tube power amplifier, which reduces the influence of temperature on the output power of the power amplifier and reduces the influence of automatic level control on the power conversion efficiency by adopting temperature compensation.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions to solve it.

[0006] A static operating point temperature compensation circuit of a high-efficiency MOS tube power amplifier, one end of which is connected to an input voltage, and the other end is connected to a MOS power amplifier tube, the temperature compensation circuit comprising: a temperature sensing compensation bias circuit and an isolation output circuit, wherein the temperature sensing compensation bias circuit comprises a resistor R5, a resistor R8, a resistor R9, a transistor V1 and a voltage regulating unit;

[0007] The emitter of the transistor V1 is grounded, the collector is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the voltage regulating unit;

[0008] One end of the voltage regulating unit is connected to the input voltage, and the other end is grounded;

[0009] One end of the resistor R8 is connected to the base of the transistor V1, and the other end is connected to the collector of the transistor V1;

[0010] One end of the resistor R9 is connected to the base of the transistor V1, and the other end is connected to the emitter of the transistor V1;

[0011] The isolated output circuit comprises a resistor R7, a resistor R10, an integrated operational amplifier N1A and a magnetic bead E1;

[0012] One end of the resistor R7 is connected to the output voltage of the temperature sensor compensation bias circuit, and the other end of the resistor R7 is connected to the positive end of the integrated operational amplifier N1A. The output voltage of the integrated operational amplifier N1A is connected to the gate of the MOS power amplifier tube through the magnetic bead E1;

[0013] The resistor R10 is connected to the inverting terminal and the output terminal of the integrated operational amplifier N1A.

[0014] Furthermore, the voltage regulating unit includes resistors R1, R2, R3 and a potentiometer RP1, the two fixed ends of the potentiometer RP1 are respectively connected to one end of the resistors R2 and R3, the other end of the resistor R2 is connected to the input voltage, and the other end of the resistor R3 is grounded; the free end of the potentiometer RP1 is connected to the resistor R5; and the two fixed ends of the potentiometer RP1 are also connected in parallel with the resistor R1.

[0015] Furthermore, a resistor R4 is provided between the collector of the transistor V1 and the input voltage.

[0016] Furthermore, a resistor R6 is provided between the collector of the transistor V1 and the resistor R5.

[0017] Furthermore, a capacitor C1 is connected between the collector and emitter of the transistor V1.

[0018] Furthermore, a capacitor C2 is connected between the output end of the temperature sensing compensation bias circuit and the ground.

[0019] A high-efficiency MOS tube power amplifier comprises: an automatic level loop control unit, a temperature compensation circuit, and an attenuator, an MMC amplifier, an input matching unit, a MOS power amplifier tube and an output matching circuit connected in sequence from a radio frequency excitation input end to a power output end; the automatic level loop control unit samples and detects the power outputted by the output matching circuit through a power sampling unit, and adjusts the attenuation of the attenuator accordingly to control the output power of the power amplifier; the output end of the temperature compensation circuit is connected to the gate of the MOS power amplifier tube, and is used to provide a variable static operating point voltage with temperature compensation to the MOS power amplifier tube.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention aims at the demand of high-efficiency special applications, that is, in the case of strictly limiting the power consumption of the amplifier and large changes in the temperature of the operating environment, by utilizing the temperature change characteristics of the static voltage of the triode and the FET field effect tube for compensation amplification, and using an integrated operational amplifier for isolated output, to provide a variable static operating point voltage with temperature compensation to the MOS field effect tube, thereby realizing compensation control of the output power when the temperature changes, and reducing the adverse effects of the deep ALC loop control. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] Figure 1 It is a power control principle block diagram of an existing MOS tube power amplifier;

[0024] Figure 2 It is a power control principle block diagram of the MOS tube power amplifier of the present invention;

[0025] Figure 3 A static operating point temperature compensation circuit diagram of a high-efficiency MOS tube power amplifier according to an embodiment of the present invention;

[0026] In the above figure, 100 is a temperature sensor compensation bias circuit; 110 is a voltage regulating unit; and 200 is an isolation output circuit. DETAILED DESCRIPTION

[0027] The embodiments and effects of the present invention are further described in detail below with reference to the accompanying drawings.

[0028] refer to Figure 3 , an embodiment of the present invention provides a static operating point temperature compensation circuit of a high-efficiency MOS tube power amplifier, one end of which is connected to an input voltage, and the other end is connected to a MOS power amplifier tube, the temperature compensation circuit comprises: a temperature sensing compensation bias circuit 100 and an isolation output circuit 200, wherein the temperature sensing compensation bias circuit 100 comprises a resistor R5, a resistor R8, a resistor R9, a transistor V1 and a voltage regulating unit 110; the emitter of the transistor V1 is grounded, the collector is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the voltage regulating unit 110; one end of the voltage regulating unit 110 is connected to the input voltage, and the other end is grounded;

[0029] One end of the resistor R8 is connected to the base of the transistor V1, and the other end is connected to the collector of the transistor V1; one end of the resistor R9 is connected to the base of the transistor V1, and the other end is connected to the emitter of the transistor V1; the isolated output circuit 200 includes a resistor R7, a resistor R10, an integrated operational amplifier N1A and a magnetic bead E1; one end of the resistor R7 is connected to the output voltage of the temperature sensor compensation bias circuit 100, and the other end of the resistor R7 is connected to the positive end of the integrated operational amplifier N1A, and the output end voltage of the integrated operational amplifier N1A is connected to the gate of the MOS power amplifier tube through the magnetic bead E1; the resistor R10 is connected to the reverse end and the output end of the integrated operational amplifier N1A.

[0030] The voltage regulating unit 110 includes a resistor R1, a resistor R2, a resistor R3 and a potentiometer RP1, wherein two fixed ends of the potentiometer RP1 are respectively connected to one end of the resistor R2 and the resistor R3, the other end of the resistor R2 is connected to the input voltage, and the other end of the resistor R3 is grounded; the free end of the potentiometer RP1 is connected to the resistor R5; and the two fixed ends of the potentiometer RP1 are also connected in parallel with the resistor R1.

[0031] In the above embodiments, the static operating point temperature compensation circuit of the present invention is composed of two parts, including a temperature sensing compensation bias circuit 100 and an isolation output circuit 200. The specific circuit diagram is shown in FIG. Figure 3 shown.

[0032] The static operating point temperature compensation circuit is powered by +8V; resistors R4, R8, R9 and transistor V1 are temperature sensing compensation circuits. By utilizing the characteristic that the PN junction conduction voltage of transistor V1 changes with temperature, R8 and R9 use different ratios to achieve amplification of the temperature ratio; resistors R1, R2, R3 and potentiometer RP1 adjust the gate voltage of the MOS power amplifier tube through voltage division, and R5 superimposes the gate bias and temperature compensation; resistors R7, R10, integrated operational amplifier N1A and magnetic bead E1 are emitter-follower isolation output circuit 200, which isolates and outputs the bias voltage that changes with temperature provided by the temperature sensing compensation bias circuit 100 to the gate of the power amplifier tube. Capacitors C1 and C2 are filter capacitors.

[0033] The transistor V1 in the present invention is a temperature sensor, and its installation position should be as close to the power amplifier tube as possible;

[0034] U1 is the sampling and amplifying voltage. The resistance of potentiometer RP1 is much larger than R1. The sampling and amplifying voltage U1 varies between 8*R3 / (R1+R2+R3) and 8*(R1+R3) / (R1+R2+R3). By adjusting the resistance of R1, the bias voltage adjustment range can be covered.

[0035] U2 is the fixed bias voltage provided by the transistor V1 temperature sensor, U2 = (0.7 + V 温漂 )*(1+R8 / R9), V 温漂 It is the value after the sampling voltage that changes with temperature is amplified, that is, the voltage change with temperature; by adjusting the ratio of R8 and R9, the voltage value at point U2 can be changed to achieve different temperature change control rates.

[0036] U3 is the output synthetic bias voltage of the temperature sensing compensation bias circuit 100, and its value is: U3 = U1 + (U2-U1) * R5 / (R5+R6), and the fusion of temperature compensation and bias is achieved through the resistor R5.

[0037] refer to Figure 2 Another embodiment of the present invention provides a high-efficiency MOS tube power amplifier, comprising: an automatic level loop control unit, a temperature compensation circuit, and an attenuator, an MMC amplifier, an input matching unit, a MOS power amplifier tube, and an output matching circuit connected in sequence from a radio frequency excitation input end to a power output end; the automatic level loop control unit samples and detects the power outputted by the output matching circuit through a power sampling unit, and adjusts the attenuation of the attenuator accordingly to control the output power of the power amplifier; the output end of the temperature compensation circuit is connected to the gate of the MOS power amplifier tube, and is used to provide a variable static operating point voltage with temperature compensation to the MOS power amplifier tube.

[0038] The present invention aims at high-efficiency power amplifiers with large ambient temperature changes, high-efficiency special application requirements and the adverse effects of power control of deep ALC loops in power amplifier circuits. By adopting a temperature compensation method to reduce the influence of temperature on the output power of the power amplifier, a temperature compensation bias circuit is designed. By utilizing the temperature change characteristics of the static voltage of triodes and FET field effect tubes for compensation amplification, and using an integrated operational amplifier for isolated output, a variable static operating point voltage with temperature compensation is provided to the MOS field effect tube, thereby realizing compensation control of the output power when the temperature changes. The temperature compensation circuit of the present invention is simple to implement and low in cost. The circuit can improve the economy of special power amplifiers with large temperature changes and high power amplifier conversion efficiency, and can also provide sampling signals for power amplifier over-temperature protection.

[0039] The present invention is realized by building a circuit module with simple discrete devices, and can be used as a static operating point function circuit in the design process of a power amplifier. The problem of low power conversion efficiency at different temperatures of the existing power amplifier circuit using constant bias and ALC control is solved, and the high efficiency of power conversion at different temperatures of the power amplifier is achieved by using an operating point temperature compensation circuit to replace the ALC loop control.

[0040] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A static operating point temperature compensation circuit for a high-efficiency MOS tube power amplifier, one end of which is connected to an input voltage and the other end is connected to a MOS power amplifier tube, characterized in that: The temperature compensation circuit includes: a temperature sensing compensation bias circuit and an isolation output circuit, wherein the temperature sensing compensation bias circuit includes a resistor R5, a resistor R8, a resistor R9, a transistor V1 and a voltage regulating unit; The emitter of the transistor V1 is grounded, the collector is connected to one end of the resistor R5, and the other end of the resistor R5 is connected to the voltage regulating unit; One end of the voltage regulating unit is connected to the input voltage, and the other end is grounded; One end of the resistor R8 is connected to the base of the transistor V1, and the other end is connected to the collector of the transistor V1; One end of the resistor R9 is connected to the base of the transistor V1, and the other end is connected to the emitter of the transistor V1; The isolated output circuit comprises a resistor R7, a resistor R10, an integrated operational amplifier N1A and a magnetic bead E1; One end of the resistor R7 is connected to the output voltage of the temperature sensor compensation bias circuit, and the other end of the resistor R7 is connected to the positive end of the integrated operational amplifier N1A. The output voltage of the integrated operational amplifier N1A is connected to the gate of the MOS power amplifier tube through the magnetic bead E1; The resistor R10 is connected to the reverse end and the output end of the integrated operational amplifier N1A; The voltage regulating unit comprises a resistor R1, a resistor R2, a resistor R3 and a potentiometer RP1, wherein two fixed ends of the potentiometer RP1 are respectively connected to one end of the resistor R2 and the resistor R3, the other end of the resistor R2 is connected to the input voltage, and the other end of the resistor R3 is grounded; the free end of the potentiometer RP1 is connected to the resistor R5; and the two fixed ends of the potentiometer RP1 are also connected in parallel with the resistor R1; A resistor R4 is provided between the collector of the transistor V1 and the input voltage.

2. The static operating point temperature compensation circuit of the high-efficiency MOS tube power amplifier according to claim 1, characterized in that: A resistor R6 is provided between the collector of the transistor V1 and the resistor R5 .

3. The static operating point temperature compensation circuit of the high-efficiency MOS tube power amplifier according to claim 1, characterized in that: A capacitor C1 is connected between the collector and emitter of the transistor V1.

4. The static operating point temperature compensation circuit of the high-efficiency MOS tube power amplifier according to claim 3, characterized in that: A capacitor C2 is connected between the output end of the temperature sensing compensation bias circuit and the ground.

5. A high-efficiency MOS tube power amplifier, characterized in that: include: An automatic level loop control unit, a temperature compensation circuit as described in any one of claims 1 to 4, and an attenuator, an MMC amplifier, an input matching unit, a MOS power amplifier tube and an output matching circuit connected in sequence from the RF excitation input end to the power output end; the automatic level loop control unit samples and detects the power output of the output matching circuit through a power sampling unit, and adjusts the attenuation of the attenuator accordingly to control the output power of the power amplifier; the output end of the temperature compensation circuit is connected to the gate of the MOS power amplifier tube, and is used to provide a variable static operating point voltage with temperature compensation to the MOS power amplifier tube.

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