A radio frequency power amplification circuit

Abstract

The utility model relates to a kind of radio frequency power amplification circuit, belong to radio frequency power amplifier technical field, solve the problem that radio frequency power amplifier in prior art is difficult to stabilize output certain power under different temperature changes.The radio frequency power amplification circuit includes: detection circuit, for receiving coupling signal and carrying out temperature compensation to coupling signal, obtains detection signal;High gain amplification circuit, for receiving detection signal and carrying out gain amplification to detection signal, obtains detection amplification signal;Power setting circuit, for according to detection amplification signal and pre-set threshold voltage output control signal to electrically-controlled attenuator.It is realized that radio frequency power amplifier stabilizes output certain power under different temperature changes.

Description

Technical Field

[0001] This utility model relates to the field of radio frequency power amplifier technology, and in particular to a radio frequency power amplifier circuit. Background Technology

[0002] Radio frequency (RF) power amplifiers have different gains when operating at different frequencies. When a stable output power of the RF power amplifier is required, a coupler is connected to the output terminal of the RF power amplifier. The coupler detects the output power and adjusts the attenuation value of the electrically adjustable attenuator in front of the RF power amplifier by detecting the signal magnitude. This changes the magnitude of the input signal to the RF power amplifier, forming a complete closed loop and achieving the purpose of dynamically adjusting the output power of the RF power amplifier.

[0003] Existing technologies typically employ detector diodes and thermistors to acquire detection signals. However, the detection performance of detector diodes varies with temperature. This results in different DC signal magnitudes after detection by the same signal at different temperatures, ultimately causing the output power of the RF power amplifier to fluctuate with ambient temperature. Furthermore, the temperature change rate of the thermistor differs significantly from that of the detector diode, leading to unsatisfactory results and making it difficult for the RF power amplifier to maintain a stable output power under varying temperature conditions.

[0004] Therefore, there is an urgent need for a technical solution for an RF power amplifier circuit that can stably output a certain power at different temperatures. Utility Model Content

[0005] Based on the above analysis, the present invention aims to provide a radio frequency power amplifier circuit to solve the problem that in the prior art, radio frequency power amplifiers are difficult to stably output a certain power under different temperature changes.

[0006] The purpose of this utility model is mainly achieved through the following technical solution: a radio frequency power amplifier circuit, which includes an electrically adjustable attenuator, a radio frequency power amplifier, a radio frequency coupler, a detector circuit, a high-gain amplifier circuit, and a power setting circuit connected in sequence.

[0007] An electrically adjustable attenuator is used to attenuate the input original radio frequency signal according to a control signal to obtain an attenuated radio frequency signal.

[0008] An RF power amplifier is used to receive attenuated RF signals and amplify them to obtain high-power RF signals.

[0009] A radio frequency coupler is used to receive high-power radio frequency signals and couple them together to obtain a coupled signal.

[0010] The detector circuit is used to receive the coupled signal and perform temperature compensation on the coupled signal to obtain the detected signal;

[0011] A high-gain amplifier circuit is used to receive the detected signal and amplify the detected signal to obtain the amplified detected signal.

[0012] The power setting circuit is used to output a control signal to the electrically adjustable attenuator based on the detector amplification signal and the preset threshold voltage.

[0013] Based on further improvements to the above scheme, the detection circuit includes a detection network circuit and a compensation network circuit.

[0014] The input terminal of the detector network circuit is connected to the coupling terminal of the radio frequency coupler, and the output terminal of the detector network circuit is connected to the input terminal of the compensation network circuit. The detector network circuit detects the coupled signal and transmits the detected signal to the compensation network circuit.

[0015] The output of the compensation network circuit is connected to the input of the high-gain amplifier circuit. The compensation network circuit performs temperature compensation on the detected signal and transmits the temperature-compensated detected signal to the high-gain amplifier circuit.

[0016] Based on a further improvement of the above scheme, the detector network circuit includes a tenth resistor R10, a first diode D1, a third capacitor C3, and a fourth capacitor C4.

[0017] One end of the tenth resistor R10 is connected to the positive terminal of the first diode D1 and serves as the input terminal of the detector network circuit.

[0018] The cathode of the first diode D1 is connected to one end of the third capacitor C3 and one end of the fourth capacitor C4, and serves as the output terminal of the detector network circuit.

[0019] The other end of the third capacitor C3 is grounded, the other end of the fourth capacitor C4 is grounded, and the other end of the tenth resistor R10 is grounded.

[0020] Based on a further improvement of the above scheme, the compensation network circuit includes an eleventh resistor R11, a twelfth resistor R12, and a second diode D2;

[0021] One end of the eleventh resistor R11 serves as the input terminal of the compensation network circuit;

[0022] The other end of the eleventh resistor R11 is connected to one end of the twelfth resistor R12, serving as the output terminal of the compensation network circuit;

[0023] The other end of the twelfth resistor R12 is connected to the positive terminal of the second diode D2, and the negative terminal of the second diode D2 is grounded.

[0024] Based on further improvements to the above scheme, the high-gain amplifier circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, and a first operational amplifier N1A;

[0025] One end of the first resistor R1 is connected to the non-inverting input of the first operational amplifier N1A and serves as the input of the high-gain amplifier circuit; the other end of the first resistor R1 is grounded.

[0026] One end of the second resistor R2 is connected to one end of the third resistor R3, one end of the first capacitor C1, and the inverting input of the first operational amplifier N1A; the other end of the second resistor R2 is grounded.

[0027] The other end of the third resistor R3 and the other end of the first capacitor C1 are both connected to the output terminal of the first operational amplifier N1A, which serves as the output terminal of the high-gain amplifier circuit.

[0028] Based on further improvements to the above scheme, the power setting circuit includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an adjustable resistor RP1, an eighth resistor R8, a second capacitor C2, and a second operational amplifier N1B.

[0029] The non-inverting input of the second operational amplifier N1B is connected to one end of the fifth resistor R5 and one end of the fourth resistor R4; the other end of the fifth resistor R5 is grounded; the other end of the fourth resistor R4 serves as the input of the power setting circuit and is connected to the output of the high-gain amplifier circuit.

[0030] The inverting input of the second operational amplifier N1B is connected to one end of the sixth resistor R6, one end of the eighth resistor R8, and one end of the second capacitor C2; the other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and the fixed end of the adjustable resistor RP1; the other end of the seventh resistor R7 is grounded; the sliding end of the adjustable resistor RP1 is connected to the power supply VCC.

[0031] The output of the second operational amplifier N1B is connected to the other end of the eighth resistor R8 and the other end of the second capacitor C2, and is connected to the control terminal of the electrically adjustable attenuator as the output of the power setting circuit.

[0032] Based on the further improvement of the above scheme, the first operational amplifier N1A and the second operational amplifier N1B both adopt independent single-channel operational amplifier integrated circuits.

[0033] Based on a further improvement of the above scheme, the electrically adjustable attenuator is a JL3A3 electrically adjustable attenuator.

[0034] Based on further improvements to the above scheme, the radio frequency power amplifier is a GFG2189A power amplifier.

[0035] Based on a further improvement of the above scheme, the radio frequency coupler is a GCO2151 coupler.

[0036] Compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0037] By performing temperature compensation on the coupled signal transmitted by the coupler in the detection circuit, the same coupled signal can generate the same detection signal at different temperatures, thereby enabling the RF power amplifier to stably generate a certain power at different temperatures.

[0038] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages will become apparent from the description or be learned by practicing this invention. The objectives and other advantages of this invention can be realized and obtained from the details specifically pointed out in the text and accompanying drawings. Attached Figure Description

[0039] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0040] Figure 1 This is a schematic diagram of the structure of a radio frequency power amplifier circuit provided by this utility model. Detailed Implementation

[0041] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0042] A specific embodiment of this utility model discloses a radio frequency power amplifier circuit, such as... Figure 1 As shown, the radio frequency power amplifier circuit includes an electrically adjustable attenuator, a radio frequency power amplifier, a radio frequency coupler, a detector circuit, a high-gain amplifier circuit, and a power setting circuit connected in sequence.

[0043] An electrically adjustable attenuator is used to attenuate the input original radio frequency signal according to a control signal to obtain an attenuated radio frequency signal.

[0044] An RF power amplifier is used to receive attenuated RF signals and amplify them to obtain high-power RF signals.

[0045] A radio frequency coupler is used to receive high-power radio frequency signals and couple them together to obtain a coupled signal.

[0046] The detector circuit is used to receive the coupled signal and perform temperature compensation on the coupled signal to obtain the detected signal;

[0047] A high-gain amplifier circuit is used to receive the detected signal and amplify the detected signal to obtain the amplified detected signal.

[0048] The power setting circuit is used to output a control signal to the electrically adjustable attenuator based on the detector amplification signal and the preset threshold voltage.

[0049] Specifically, such as Figure 1 As shown, the original RF signal to be attenuated is input to the RF input terminal PORT1 of the electrically adjustable attenuator. After attenuation in the attenuator, the attenuated RF signal is obtained, and then output through the RF output terminal PORT2 of the attenuator. It is worth noting that the control signal transmitted to the attenuator via its control terminal Vctrl is used to set the attenuation level, i.e., the degree to which the original RF signal is attenuated. By changing the magnitude of the control signal, the magnitude of the attenuated RF signal can be controlled.

[0050] Specifically, such as Figure 1 As shown, the attenuated RF signal is transmitted to the RF power amplifier through the RF input terminal RF IN of the RF power amplifier. The RF power amplifier amplifies the signal to obtain a high-power RF signal, which is then transmitted to the RF coupler through the RF output terminal RF OUT of the RF power amplifier.

[0051] Specifically, such as Figure 1 As shown, a high-power radio frequency signal is transmitted to the radio frequency coupler through the input terminal INPUT. In the radio frequency coupler, the power of the high-power radio frequency signal is determined by coupling the high-power radio frequency signal to obtain the coupled signal. At the same time, the high-power radio frequency signal is transmitted to the load through the output terminal OUTPUT of the radio frequency coupler.

[0052] Specifically, such as Figure 1 As shown, the coupled signal generated by the RF coupler is transmitted to the input terminal of the detector circuit. The coupled signal is detected in the detector circuit, and temperature compensation is performed on the coupled signal so that the coupled signal at different temperatures generates the same detected signal. The detected signal is transmitted to the input terminal of the high-gain amplifier circuit through the output terminal of the detector circuit.

[0053] Specifically, such as Figure 1 As shown, after receiving the detection signal, the high-gain amplifier circuit amplifies the detection signal to obtain the amplified detection signal, which is then transmitted to the input of the power setting circuit through the output of the high-gain amplifier circuit.

[0054] Specifically, such as Figure 1 As shown, in the power setting circuit, the control signal is determined based on the detector amplification signal and the threshold voltage, and the control signal is transmitted to the electrically adjustable attenuator through the output terminal of the power setting circuit to control the attenuation of the original radio frequency signal by the electrically adjustable attenuator.

[0055] It is understandable that in an RF power amplifier circuit, the control signal is dynamically adjusted at different temperatures to ensure that the RF power amplifier can output a stable power.

[0056] Preferably, the electrically adjustable attenuator is a JL3A3 electrically adjustable attenuator.

[0057] Preferably, the radio frequency power amplifier is a GFG2189A power amplifier.

[0058] Preferably, the radio frequency coupler is a GCO2151 coupler.

[0059] Preferably, the detection circuit includes a detection network circuit and a compensation network circuit;

[0060] The input terminal of the detector network circuit is connected to the coupling terminal of the radio frequency coupler, and the output terminal of the detector network circuit is connected to the input terminal of the compensation network circuit. The detector network circuit detects the coupled signal and transmits the detected signal to the compensation network circuit.

[0061] The output of the compensation network circuit is connected to the input of the high-gain amplifier circuit. The compensation network circuit performs temperature compensation on the detected signal and transmits the temperature-compensated detected signal to the high-gain amplifier circuit.

[0062] Specifically, a detection network circuit and a compensation network circuit are set up in the detection circuit. The detection network circuit is used to detect the coupled signal and transmit the detected signal to the compensation network circuit. The compensation network circuit performs temperature compensation on the detected signal so that the same coupled signal always produces the same detected signal when passing through the detection circuit at different temperatures.

[0063] Preferably, the detector network circuit includes a tenth resistor R10, a first diode D1, a third capacitor C3, and a fourth capacitor C4;

[0064] One end of the tenth resistor R10 is connected to the positive terminal of the first diode D1 and serves as the input terminal of the detector network circuit.

[0065] The cathode of the first diode D1 is connected to one end of the third capacitor C3 and one end of the fourth capacitor C4, and serves as the output terminal of the detector network circuit.

[0066] The other end of the third capacitor C3 is grounded, the other end of the fourth capacitor C4 is grounded, and the other end of the tenth resistor R10 is grounded.

[0067] Preferably, the compensation network circuit includes an eleventh resistor R11, a twelfth resistor R12, and a second diode D2;

[0068] One end of the eleventh resistor R11 serves as the input terminal of the compensation network circuit;

[0069] The other end of the eleventh resistor R11 is connected to one end of the twelfth resistor R12, serving as the output terminal of the compensation network circuit;

[0070] The other end of the twelfth resistor R12 is connected to the positive terminal of the second diode D2, and the negative terminal of the second diode D2 is grounded.

[0071] Specifically, such as Figure 1 As shown, the coupled signal is input to the positive terminal of the first diode D1 and one end of the tenth resistor R10. After being filtered by the third capacitor C3 and the fourth capacitor C4, it is then passed through the eleventh resistor R11 to obtain the detection signal Vp1.

[0072] Preferably, the high-gain amplifier circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, and a first operational amplifier N1A;

[0073] One end of the first resistor R1 is connected to the non-inverting input of the first operational amplifier N1A and serves as the input of the high-gain amplifier circuit; the other end of the first resistor R1 is grounded.

[0074] One end of the second resistor R2 is connected to one end of the third resistor R3, one end of the first capacitor C1, and the inverting input of the first operational amplifier N1A; the other end of the second resistor R2 is grounded.

[0075] The other end of the third resistor R3 and the other end of the first capacitor C1 are both connected to the output terminal of the first operational amplifier N1A, which serves as the output terminal of the high-gain amplifier circuit.

[0076] Preferably, the power setting circuit includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an adjustable resistor RP1, an eighth resistor R8, a second capacitor C2, and a second operational amplifier N1B.

[0077] The non-inverting input of the second operational amplifier N1B is connected to one end of the fifth resistor R5 and one end of the fourth resistor R4; the other end of the fifth resistor R5 is grounded; the other end of the fourth resistor R4 serves as the input of the power setting circuit and is connected to the output of the high-gain amplifier circuit.

[0078] The inverting input of the second operational amplifier N1B is connected to one end of the sixth resistor R6, one end of the eighth resistor R8, and one end of the second capacitor C2; the other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and the fixed end of the adjustable resistor RP1; the other end of the seventh resistor R7 is grounded; the sliding end of the adjustable resistor RP1 is connected to the power supply VCC.

[0079] The output of the second operational amplifier N1B is connected to the other end of the eighth resistor R8 and the other end of the second capacitor C2, and is connected to the control terminal of the electrically adjustable attenuator as the output of the power setting circuit.

[0080] Specifically, for example, suppose the output power of the desired RF power amplifier is stabilized at P. w At this time, the coupler couples the signal V. s After detection by the first detector diode D1, the detected signal voltage V is output through the eleventh resistor R11. P1 for:

[0081]

[0082] Among them, R 10 R is the resistance value of the tenth resistor R10. 11 R is the resistance value of the eleventh resistor R11. 12 The resistance value of the twelfth resistor R12 is V. F1 V is the voltage difference across the first detector diode D1. F2 This represents the voltage difference across the second detector diode D2.

[0083] The voltage V3 at pin 3 of the first operational amplifier N1A in the high-gain amplifier circuit is equal to the detector signal V. P1 The voltage V1 at pin 1 of the first operational amplifier N1A is:

[0084]

[0085] The voltage V5 at pin 5 of the second operational amplifier N1B in the power setting circuit is:

[0086]

[0087] Where R2 is the resistance of the second resistor R2, R3 is the resistance of the third resistor R3, R4 is the resistance of the fourth resistor R4, and R5 is the resistance of the fifth resistor R5.

[0088] It is worth noting that in practical applications, the voltage V6 can be adjusted by adjusting the resistance value of the adjustable resistor RP1.

[0089] Specifically, when the output power P of the RF power amplifier w When there is an increasing trend, the detected signal VP1 This will also increase, causing voltages V1 and V5 to increase. When voltage V5 is greater than voltage V6, the voltage V7 at pin 7 of the second operational amplifier N1B will no longer be 0. Therefore:

[0090] V7 = βB × (V5 - V6);

[0091] Where, β B As the gain of the second operational amplifier N1B increases, the voltage V7 increases, resulting in greater attenuation from the electrically adjustable attenuator, reducing the signal entering the RF power amplifier, and preventing P from being properly amplified. w The increase of ...

[0092] Preferably, the first operational amplifier N1A and the second operational amplifier N1B are both independent single-channel operational amplifier integrated circuits.

[0093] Specifically, the first operational amplifier N1A and the second operational amplifier N1B use independent single-channel operational amplifier integrated circuits, so that the two do not interfere with each other and the layout is flexible.

[0094] The technical effects of the radio frequency power amplifier circuit provided by this utility model are illustrated below through a specific embodiment.

[0095] The output power of the RF power amplifier is expected to stabilize at P. w The voltage is 200W, and the coupling signal V of the RF coupler is at this time. s With an effective value of 1.5V and an ambient temperature of 10℃, the forward voltage drop V of the first diode D1 and the second diode D2 is... F1 =V F2 =0.25 (V), take R 10 =R 11 =R 12 =50Ω, output detector signal voltage V through the eleventh resistor R11 P1 for:

[0096]

[0097] Specifically, the resistance of the tenth resistor R10 is 50Ω, the resistance of the eleventh resistor R11 is 50Ω, and the resistance of the twelfth resistor R12 is 50Ω.

[0098] The voltage V5 at pin 5 of the second operational amplifier N1B in the power setting circuit is:

[0099]

[0100] Specifically, the resistance of the second resistor R2 is 5kΩ, the resistance of the third resistor R3 is 15kΩ, the resistance of the fourth resistor R4 is 5kΩ, and the resistance of the fifth resistor R5 is 5kΩ.

[0101] Adjust the resistance of the adjustable resistor RP1 so that V6 = V5 = 1 (V). At this time, the voltage V7 at pin 7 of the second operational amplifier N1B is 0, the attenuation value of the electrically adjustable attenuator remains unchanged, and the output power P of the RF power amplifier remains unchanged. w The set power value is 200W.

[0102] As the original RF signal is further amplified, the RF power amplifier output power P... w There is an increasing trend. Suppose the power reaches 220W at a certain instant, at which point the coupling signal V of the coupler... s The corresponding effective value is 1.65V, and the output detector signal voltage V is obtained through the eleventh resistor R11. P1 for:

[0103]

[0104] The voltage V5 at pin 5 of the second operational amplifier N1B in the power setting circuit is:

[0105]

[0106] At this point, the threshold voltage V6 remains at the previously adjusted value of 1V, V5 > V6, and the voltage V7 at pin 7 of the second operational amplifier N1B is no longer 0, therefore:

[0107] V7 = β B ×(V5-V6)=10×(1.1-1.0)=1(V);

[0108] Where, β B The gain of the second operational amplifier N2B is set to 10. With V7 = 1 (V), the attenuation of the electrically tunable attenuator increases, reducing the attenuated RF signal entering the RF power amplifier and preventing P from... w The increase of P until w When the voltage drops to the set 200W, the coupling signal decreases, the voltage V1 decreases, the voltage V5 decreases to be equivalent to the set threshold voltage V6, and the output of V7 is 0, thus achieving dynamic balance.

[0109] For example, without the compensation network circuit composed of the eleventh resistor R11, the twelfth resistor R12, and the second diode D2 in the detector circuit provided by this utility model, in P w When the power is 200W and the ambient temperature is 10℃, the forward voltage drop of the detector diode D1 is V. F1 =0.30V, when the ambient temperature is 30℃, the forward voltage drop of the detector diode is V. F1 =0.25V, the coupling signal V of the coupler sUnaffected by temperature, the corresponding effective value is 1.5V. There is no compensation network circuit. The detector signal voltage is V. P1 The power is directly supplied by the negative terminal of the detector diode D1, as follows:

[0110] V P1 =V s -V F1 ;

[0111] At 10℃, the forward voltage drop of the detector diode is V. F1 =0.30V, at this time, the detector signal V P1 The voltage is 1.2V. After passing through the high-gain amplifier circuit, the voltage V5 is 2.4V. At this time, the threshold voltage V6 is set to 2.4V. The voltages at pins 5 and 6 of the second operational amplifier N1B are equal, and the voltage at pin 7, V7, is exactly 0. The output power P w It stabilizes at 200 (W).

[0112] At 30℃, the voltage drop across the detector diode decreases by 0.05V, becoming V. F1 =0.25V, at this time, the detector signal V P1 The voltage is 1.25V. After passing through the high-gain amplifier circuit, the voltage V5 is 2.5V. At this time, the set threshold voltage V6 remains unchanged at 2.4V. The voltage at pin 5 of the second operational amplifier N1B is greater than the voltage at pin 6, and the voltage at pin 7, V7, is not 0.

[0113] V7 = β B ×(V5-V6)=10×(2.5-2.4)=1(V);

[0114] If V7 = 1 (V), then the electronically adjustable attenuator attenuates more, the attenuated RF signal entering the RF power amplifier decreases, and the output power P... w Decrease when output power P w When reduced to 180 (W), the coupler coupling signal V s The corresponding effective value is 1.45V, V F1 =0.25V, detector signal V P1 The voltage is 1.20V. After passing through the high-gain amplifier circuit, the voltage V5 is 2.4V. At this time, the set threshold voltage V6 remains unchanged at 2.4V. The voltage at pin 5 of the second operational amplifier N1B is equal to the voltage at pin 6, and the voltage at pin 7, V7, is 0. The RF power amplifier output is stable, but the power value is 180 (W).

[0115] Therefore, it can be seen that when there is no compensation network circuit, the output power of the RF power amplifier changes with the ambient temperature because the voltage drop of the detector diode changes with temperature.

[0116] This utility model employs a compensation network circuit composed of the eleventh resistor R11, the twelfth resistor R12, and the second diode D2, in P w When the power is 200W and the ambient temperature is 10℃, the forward voltage drop of the detector diode is V. F1 =0.30V, when the ambient temperature is 30℃, the forward voltage drop of the detector diode is V. F1 =0.25V, the coupling signal V of the coupler s Unaffected by temperature, the corresponding effective value is 1.5V, and the output detector signal voltage V is obtained through the eleventh resistor R11. P1 for:

[0117]

[0118] When R11 equals R12, we have:

[0119]

[0120] From the formula above, we can see that the detector signal voltage V P1 Since the voltage drop of the detector diode is irrelevant, changes in the temperature of the detector diode will not cause changes in the output power of the RF power amplifier.

[0121] It is worth noting that the radio frequency power amplifier circuit provided in this embodiment controls the magnitude of the preceding and following radio frequency signals input to the radio frequency power amplifier, thereby controlling the magnitude of the high-power radio frequency signal output by the radio frequency power amplifier.

[0122] Specifically, when a certain amount of original RF signal is input to the electrically adjustable attenuator, and the high-power RF signal output by the RF power amplifier exceeds the set power, the coupling signal generated by the coupler is detected by the detection circuit and amplified by the high-gain amplifier circuit. The voltage of the detected and amplified signal exceeds the preset threshold voltage for amplitude stabilization. The power setting circuit outputs a control signal voltage to the electrically adjustable attenuator, which attenuates the signal, thus reducing the attenuated RF signal entering the RF power amplifier and lowering the output power. This maintains a dynamic balance and stabilizes the output power at the set value.

[0123] Specifically, after the coupled signal from the coupler is detected by the detector diode and filtered by the capacitor, it is not simply passed to the high-gain amplifier circuit. Instead, a compensation network circuit composed of resistors and detector diodes performs temperature compensation before outputting the signal to the high-gain amplifier circuit. When the temperature changes, the same coupled signal will change in magnitude after being detected by the detector diode. This change is counteracted by the compensation network circuit, effectively controlling the output signal of the detector circuit to remain constant despite temperature variations. After amplification by the high-gain amplifier circuit and comparison amplification by the power setting circuit, the voltage value of the electrically adjustable attenuator is controlled to remain unchanged with temperature variations, ensuring stable output power of the RF power amplifier.

[0124] Compared with the prior art, the radio frequency power amplifier circuit provided by this utility model provides a temperature compensation for the coupling signal transmitted by the coupler in the detection circuit, so that the same coupling signal generates the same detection signal at different temperatures, thereby enabling the radio frequency power amplifier to stably generate a certain power at different temperatures.

[0125] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A radio frequency power amplifier circuit, characterized in that, The radio frequency power amplifier circuit includes an electrically adjustable attenuator, a radio frequency power amplifier, a radio frequency coupler, a detector circuit, a high-gain amplifier circuit, and a power setting circuit connected in sequence. An electrically adjustable attenuator is used to attenuate the input original radio frequency signal according to a control signal to obtain an attenuated radio frequency signal. An RF power amplifier is used to receive attenuated RF signals and amplify them to obtain high-power RF signals. A radio frequency coupler is used to receive high-power radio frequency signals and couple them together to obtain a coupled signal. The detector circuit is used to receive the coupled signal and perform temperature compensation on the coupled signal to obtain the detected signal; A high-gain amplifier circuit is used to receive the detected signal and amplify the detected signal to obtain the amplified detected signal. The power setting circuit is used to output a control signal to the electrically adjustable attenuator based on the detected and amplified signal and the preset threshold voltage.

2. The radio frequency power amplifier circuit according to claim 1, characterized in that, The detection circuit includes a detection network circuit and a compensation network circuit; The input terminal of the detector network circuit is connected to the coupling terminal of the radio frequency coupler, and the output terminal of the detector network circuit is connected to the input terminal of the compensation network circuit. The detector network circuit detects the coupled signal and transmits the detected signal to the compensation network circuit. The output of the compensation network circuit is connected to the input of the high-gain amplifier circuit. The compensation network circuit performs temperature compensation on the detected signal and transmits the temperature-compensated detected signal to the high-gain amplifier circuit.

3. The radio frequency power amplifier circuit according to claim 2, characterized in that, The detector network circuit includes a tenth resistor R10, a first diode D1, a third capacitor C3, and a fourth capacitor C4. One end of the tenth resistor R10 is connected to the positive terminal of the first diode D1 and serves as the input terminal of the detector network circuit. The cathode of the first diode D1 is connected to one end of the third capacitor C3 and one end of the fourth capacitor C4, and serves as the output terminal of the detector network circuit. The other end of the third capacitor C3 is grounded, the other end of the fourth capacitor C4 is grounded, and the other end of the tenth resistor R10 is grounded.

4. The radio frequency power amplifier circuit according to claim 3, characterized in that, The compensation network circuit includes an eleventh resistor R11, a twelfth resistor R12, and a second diode D2; One end of the eleventh resistor R11 serves as the input terminal of the compensation network circuit; The other end of the eleventh resistor R11 is connected to one end of the twelfth resistor R12, serving as the output terminal of the compensation network circuit; The other end of the twelfth resistor R12 is connected to the positive terminal of the second diode D2, and the negative terminal of the second diode D2 is grounded.

5. The radio frequency power amplifier circuit according to claim 2, characterized in that, The high-gain amplifier circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, and a first operational amplifier N1A; One end of the first resistor R1 is connected to the non-inverting input of the first operational amplifier N1A and serves as the input of the high-gain amplifier circuit; the other end of the first resistor R1 is grounded. One end of the second resistor R2 is connected to one end of the third resistor R3, one end of the first capacitor C1, and the inverting input of the first operational amplifier N1A; the other end of the second resistor R2 is grounded. The other end of the third resistor R3 and the other end of the first capacitor C1 are both connected to the output terminal of the first operational amplifier N1A, which serves as the output terminal of the high-gain amplifier circuit.

6. The radio frequency power amplifier circuit according to claim 5, characterized in that, The power setting circuit includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an adjustable resistor RP1, an eighth resistor R8, a second capacitor C2, and a second operational amplifier N1B. The non-inverting input of the second operational amplifier N1B is connected to one end of the fifth resistor R5 and one end of the fourth resistor R4; the other end of the fifth resistor R5 is grounded; the other end of the fourth resistor R4 serves as the input of the power setting circuit and is connected to the output of the high-gain amplifier circuit. The inverting input of the second operational amplifier N1B is connected to one end of the sixth resistor R6, one end of the eighth resistor R8, and one end of the second capacitor C2; the other end of the sixth resistor R6 is connected to one end of the seventh resistor R7 and the fixed end of the adjustable resistor RP1; the other end of the seventh resistor R7 is grounded; the sliding end of the adjustable resistor RP1 is connected to the power supply VCC. The output of the second operational amplifier N1B is connected to the other end of the eighth resistor R8 and the other end of the second capacitor C2, and is connected to the control terminal of the electrically adjustable attenuator as the output of the power setting circuit.

7. The radio frequency power amplifier circuit according to claim 6, characterized in that, The first operational amplifier N1A and the second operational amplifier N1B both use independent single-channel operational amplifier integrated circuits.

8. The radio frequency power amplifier circuit according to any one of claims 1-6, characterized in that, The electrically adjustable attenuator is a JL3A3 electrically adjustable attenuator.

9. The radio frequency power amplifier circuit according to any one of claims 1-6, characterized in that, The radio frequency power amplifier is a GFG2189A power amplifier.

10. The radio frequency power amplifier circuit according to any one of claims 1-6, characterized in that, The radio frequency coupler is a GCO2151 coupler.

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