A radio frequency signal amplitude adjustment circuit

Abstract

This invention discloses a radio frequency (RF) signal amplitude adjustment circuit, comprising a signal conditioning and matching unit, a PIN attenuation unit, a detection unit, a dual threshold comparison unit, a dynamic RC integrator unit, and a signal feedback unit connected in sequence. The output of the signal feedback unit is also connected to the input of the PIN attenuation unit. After passing through the signal conditioning and matching unit and the PIN attenuation unit, the RF input signal is split into two outputs: one is directly output, and the other is input to the detection unit and converted into a DC voltage output. When the RF input signal fluctuates within a certain amplitude, the first and second thresholds of the dual threshold comparison unit are compared with the signal output from the detection unit, and the signal enters the dynamic RC integrator unit to achieve precise and rapid response. The signal feedback unit filters the output signal of the dynamic RC integrator unit to further improve signal stability. This invention provides a low-cost circuit for adjusting signal amplitude and reduces the difficulty of RF signal adjustment.

Description

Technical Field

[0001] This utility model relates to an amplitude adjustment circuit, specifically a radio frequency signal amplitude adjustment circuit. Background Technology

[0002] In radio frequency (RF) applications such as communications, radar, and satellite navigation, the amplitude stability of RF signals directly affects system performance. In communication systems, unstable signal amplitude leads to increased bit error rate at the receiver; in radar systems, amplitude fluctuations affect target detection accuracy; and in test and measurement systems, amplitude deviations cause test errors. To address these transmission problems, the amplitude of the RF signal is typically adjusted using power control circuits. However, existing RF signal amplitude adjustment circuits are imprecise in their adjustment response, easily causing overshoot or signal loss. Furthermore, they cannot eliminate drift caused by jitter and environmental factors, ultimately resulting in inaccurate signal output stability. Utility Model Content

[0003] The purpose of this invention is to provide a radio frequency signal amplitude adjustment circuit to solve the problems of long adjustment time and low accuracy of existing radio frequency signal amplitude adjustment circuits.

[0004] The technical solution of this utility model is as follows:

[0005] A radio frequency signal amplitude adjustment circuit, comprising:

[0006] The signal conditioning and matching unit, connected to the PIN attenuation unit, is used to improve signal quality and transmission efficiency;

[0007] The PIN attenuation unit is connected to the signal conditioning and matching unit, the detection unit, and the signal feedback unit, respectively, and is used to adjust the amplitude of the input signal and output the radio frequency signal.

[0008] The detection unit is connected to the PIN attenuation unit and the dual threshold comparison unit respectively, and is used to convert the signal output by the PIN attenuation unit into a DC signal;

[0009] The dual threshold comparison unit is connected to the detection unit and the dynamic RC integrator unit respectively, and is used to generate control signals for the integral parameters and reduce the jitter of the output signal.

[0010] A dynamic RC integrator unit, connected to both the dual threshold comparison unit and the signal feedback unit, is used to integrate the output signal of the detector unit with the adaptive reference input signal to generate a control voltage; and

[0011] The signal feedback unit is connected to the dynamic RC integration unit and the PIN attenuation unit respectively. It is used for filtering and preventing signal leakage, and outputs to the PIN attenuation unit.

[0012] Furthermore, the structure of the dual threshold comparison unit is as follows: the non-inverting input of comparator U2 and the inverting input of comparator U5 are both connected to the input signal of the dual threshold comparison unit; the inverting input of comparator U2 is connected to a first threshold voltage; and the output of comparator U2 is connected to a dynamic RC integration unit via resistor R20. The non-inverting input of comparator U5 is connected to a second threshold voltage; and the output of comparator U5 is connected to a dynamic RC integration unit via resistor R21. The first threshold voltage is greater than the voltage corresponding to the target output amplitude, and the second threshold voltage is less than the voltage corresponding to the target output amplitude.

[0013] The method employs two threshold voltage comparisons. In the conventional single threshold comparison method, when the input signal amplitude fluctuates around the threshold, the comparator output will frequently flip, resulting in fluctuating output signal amplitude, jitter, and even distortion. The dual threshold method is like adding hysteresis to the system, which can avoid critical jitter, improve anti-interference capability, and stabilize the control loop.

[0014] Furthermore, the structure of the dynamic RC integrator unit is as follows: the inverting terminal of the integrator U7 is connected to three inputs. One input is connected to the emitter of transistor Q1 via resistor R25, the collector of transistor Q1 is connected to the output of the detector unit, and the base of transistor Q1 is connected to the resistor R20 of the dual threshold comparator unit. A second input is connected to the output of the detector unit via resistor R30. The third input is connected to the emitter of transistor Q2 via resistor R26, the collector of transistor Q2 is connected to the emitter of transistor Q2, and the base of transistor Q2 is connected to the resistor R20 of the dual threshold comparator unit. The output terminal of the detector unit is connected to the base of the transistor Q2 and the resistor R21 of the dual threshold comparator unit; the output terminal of the integrator U7 is connected to the power supply through capacitor C22 and resistor R30; the non-inverting input of the integrator U7 is connected to the output terminal of the follower U6; the output terminal of the integrator U7 is connected to two outputs after resistor R27, one of which is connected to the non-inverting input of the follower U6, and the other is grounded through resistor R28; the inverting input of the follower U6 is connected to the output terminal of the follower U6.

[0015] The dynamic RC integrator dynamically adjusts the integration parameters based on the output of the dual threshold comparison unit to achieve a precise response.

[0016] Furthermore, the structure of the signal conditioning and matching unit is as follows: pin 1 of amplifier U3 is connected to the input terminal of the signal conditioning and matching unit via capacitor C19, the first π-type attenuator, and capacitor C15; pin 3 of amplifier U3 has two outputs, one of which is connected to the power supply via inductor L1; the other is connected to pin 1 of amplifier U4 via capacitor C17, the second π-type attenuator, and capacitor C18; pin 3 of amplifier U4 has two outputs, one of which is connected to the power supply via inductor L2; the other is connected to the output terminal of the signal conditioning and matching unit via capacitor C16.

[0017] The signal conditioning and matching unit enhances the signal gain through a two-stage amplifier, while using a π-type attenuator for impedance matching and signal amplitude adjustment to ensure signal quality and transmission efficiency throughout the entire link.

[0018] Furthermore, the structure of the PIN attenuation unit is as follows: pin 1 of PIN diode D1 is connected to the input signal of the PIN attenuation unit via capacitor C21, the third π-type attenuator, and capacitor C20; pin 2 of PIN diode D2 is connected to pin 1 of PIN diode D2; pin 2 of PIN diode D2 has two outputs, one of which is connected to the output terminal of the PIN attenuation unit, and the other is grounded via inductor L4; pin 1 of PIN diode D1 is connected to the output terminal of the signal feedback unit.

[0019] The PIN attenuation unit is controlled by the control voltage or control current output by the signal feedback unit. It generates different attenuation amounts for different control voltages or control currents, thereby adjusting the amplitude of the input signal.

[0020] Furthermore, the structure of the detection unit is as follows: pin 1 of detector U1 is connected to the input terminal of the detection unit via capacitor C4; pin 3 of detector U1 is connected to capacitor C5 and then split into two paths, one path is connected to the input signal of the detection unit via resistor R1, and the other path is grounded; pin 4 of detector U1 is connected to the output of the detection unit via resistor R3, and pin 5 of detector U1 is connected to the output terminal of the detection unit; pin 6 of detector U1 is grounded via resistor R2; pin 7 of detector U1 is split into two paths, one path is connected to the power supply, and the other path is grounded via capacitor C1, with capacitor C2 connected in parallel across capacitor C1; pin 8 of detector U1 is grounded via capacitor C3.

[0021] The detector unit converts the output signal into a DC output.

[0022] Furthermore, the structure of the signal feedback unit is such that the input terminal of the signal feedback unit is connected to two outputs after passing through resistor R32. One output is connected to the output terminal of the signal feedback unit through inductor L3, and the other output is grounded through capacitor C23. A capacitor C24 is connected in parallel across the two ends of capacitor C23.

[0023] The signal feedback unit performs current limiting and filtering on the output signal to prevent signal leakage. After signal processing, the signal feedback unit connects to the input of the PIN attenuation unit in the RF link to adjust the attenuation.

[0024] This invention enhances signal gain and performs impedance matching and signal amplitude adjustment through a signal conditioning and matching unit. A detection unit monitors changes in the RF output amplitude in real time and converts it into a DC signal. A dual-threshold comparison unit compares the detected output voltage with two threshold voltages, using different parallel circuits for different voltages to precisely adjust the amplitude, avoiding critical state jitter and improving anti-interference capability. A dynamic RC integrator unit outputs a final control voltage, dynamically adjusting the PIN attenuation unit. An adaptive reference voltage is used to quickly compensate for input signal fluctuations, using the compensation amount to offset the fluctuations. A signal feedback unit limits current and filters to prevent signal leakage, thus ensuring stable output amplitude. This invention eliminates the need for manual adjustment, additional control circuitry, and programming, greatly reducing design and debugging difficulty, shortening the debugging cycle, and lowering the difficulty and cost of RF signal amplitude adjustment. Attached Figure Description

[0025] Figure 1 This is a general principle block diagram of this utility model.

[0026] Figure 2 This is the circuit diagram of the signal conditioning and matching unit.

[0027] Figure 3 This is the circuit diagram of the PIN attenuation unit.

[0028] Figure 4 This is the circuit diagram of the detector unit.

[0029] Figure 5 This is a circuit diagram of a dual threshold comparison unit and a dynamic RC integrator unit.

[0030] Figure 6 This is the circuit diagram of the signal feedback unit.

[0031] Figure 7 This is a graph showing the relationship between the RF resistance and forward bias current of the PIN diode.

[0032] Figure 8 This is the target output amplitude diagram. Detailed Implementation

[0033] The present invention will now be described in further detail.

[0034] like Figure 1 As shown, this utility model includes a signal conditioning and matching unit, a PIN attenuation unit, a detection unit, a dual threshold comparison unit, a dynamic RC integration unit, and a signal feedback unit connected in sequence. The output terminal of the signal feedback unit is also connected to the PIN attenuation unit.

[0035] like Figure 2As shown, the signal conditioning and matching unit includes amplifier U3, coupling capacitor C15, resistor R8, resistor R15, resistor R17, coupling capacitor C19, leakage protection inductor L1, filter capacitor C6, capacitor C8, capacitor C10, amplifier U4, coupling capacitor C17, resistor R10, resistor R16, resistor R14, coupling capacitor C18, coupling capacitor C16, leakage protection inductor L2, filter capacitor C7, capacitor C9, and capacitor C11.

[0036] The signal conditioning and matching unit is structured as follows: Pin 1 of amplifier U3 is connected to the input terminal RFIN of the signal conditioning and matching unit via capacitor C19, the first π-type attenuator, and capacitor C15; Pin 3 of amplifier U3 has two outputs: one is connected to a +5V power supply via inductor L1; the other is connected to pin 1 of amplifier U4 via capacitor C17, the second π-type attenuator, and capacitor C18; Pin 3 of amplifier U4 has two outputs: one is connected to a +5V power supply via inductor L2; the other is connected to the output terminal AMOUT of the signal conditioning and matching unit via capacitor C16. Pins 2 and 4 of amplifier U3 and amplifier U4 are grounded.

[0037] The power supply connected to inductor L1 is also connected to capacitor C6, with the other end of capacitor C6 grounded. A capacitor C8 is connected in parallel across capacitor C6, and a capacitor C10 is connected in parallel across capacitor C8. The power supply connected to inductor L2 is also connected to capacitor C7, with the other end of capacitor C7 grounded. A capacitor C9 is connected in parallel across capacitor C7, and a capacitor C11 is connected in parallel across capacitor C9.

[0038] A resistor R8 is connected between the input and output terminals of the first π-type attenuator. A resistor R15 is connected between the input terminal of the first π-type attenuator and the ground wire. A resistor R17 is connected between the output terminal of the first π-type attenuator and the ground wire. A resistor R10 is connected between the input and output terminals of the second π-type attenuator. A resistor R16 is connected between the input terminal of the second π-type attenuator and the ground wire. A resistor R14 is connected between the output terminal of the second π-type attenuator and the ground wire.

[0039] The signal conditioning and matching unit enhances the signal gain through a two-stage amplifier, while using a π-type attenuator to perform impedance matching and signal amplitude adjustment of the RF signal to ensure the signal quality and transmission efficiency of the entire link.

[0040] like Figure 3 As shown, the PIN attenuation unit includes PIN diode D1, PIN diode D2, inductor L4, coupling capacitor C20, coupling capacitor C21, resistor R9, resistor R18, and resistor R19.

[0041] The structure of the PIN attenuation unit is as follows: pin 1 of PIN diode D1 is connected to the input terminal of the PIN attenuation unit via capacitor C21, the third π-type attenuator, and capacitor C20. The input terminal of the PIN attenuation unit is connected to the output terminal AMOUT of the signal conditioning and matching unit. Pin 2 of PIN diode D2 is connected to pin 1 of PIN diode D2. Pin 2 of PIN diode D2 has two outputs, one of which is connected to the output terminal of the PIN attenuation unit, and the other is grounded via inductor L4. Pin 1 of PIN diode D1 is connected to the output terminal Vctrl of the signal feedback unit.

[0042] A resistor R9 is connected between the input and output terminals of the third π-type attenuator, a resistor R18 is connected between the input terminal of the third π-type attenuator and the ground wire, and a resistor R19 is connected between the output terminal of the third π-type attenuator and the ground wire.

[0043] Both PIN diodes D1 and D2 are model HSMP-3832.

[0044] This invention utilizes the characteristic that the impedance of a PIN diode changes with the current to adjust the fluctuation of the RF input signal amplitude. The higher the current, the lower the resistance of the PIN diode, the less the input signal attenuation, and the higher the signal amplitude input to the detector unit; conversely, the lower the current, the higher the resistance of the PIN diode, the greater the input signal attenuation, and the lower the signal amplitude input to the detector unit.

[0045] After passing through the signal conditioning and matching unit and the PIN attenuation unit, the RF input signal is divided into two paths: one path is directly output, and the other path is input to the detection unit and converted into a DC voltage output.

[0046] like Figure 4 As shown, the detection unit includes detector U1, resistor R1, capacitor C4, capacitor C5, resistor R3, resistor R2, capacitor C1, capacitor C2 and capacitor C3.

[0047] The detector unit is structured as follows: Pin 1 of detector U1 is connected to the input terminal of the detector unit via capacitor C4. The input terminal of the detector unit is connected to the output terminal RFOUT of the PIN attenuation unit. Pin 3 of detector U1 is connected to capacitor C5 and then split into two paths: one path is connected to the input signal of the detector unit via resistor R1, and the other path is grounded. Pin 4 of detector U1 is connected to the output of the detector unit via resistor R3, and pin 5 of detector U1 is connected to the output terminal of the detector unit. Pin 6 of detector U1 is grounded via resistor R2. Pin 7 of detector U1 is split into two paths: one path is connected to the power supply, and the other path is grounded via capacitor C1. Capacitor C2 is connected in parallel across capacitor C1. Pin 8 of detector U1 is grounded via capacitor C3. Pins 0 and 2 of detector U1 are both grounded.

[0048] like Figure 5As shown, the dual threshold comparison unit includes comparator U2, resistor R20, comparator U5, and resistor R21.

[0049] The structure of the dual threshold comparator unit is as follows: the non-inverting input of comparator U2 and the inverting input of comparator U5 are both connected to the input terminals of the dual threshold comparator unit. The inverting input of comparator U2 is connected to the first threshold voltage, and the output of comparator U2 is connected to the dynamic RC integrator unit via resistor R20. The non-inverting input of comparator U5 is connected to the second threshold voltage, and the output of comparator U5 is connected to the dynamic RC integrator unit via resistor R21. The positive power supply terminals of comparators U2 and U5 are both connected to a power source, and the negative power supply terminals of comparators U2 and U5 are both grounded.

[0050] The first threshold voltage is greater than the voltage corresponding to the target output amplitude, and the second threshold voltage is less than the voltage corresponding to the target output amplitude.

[0051] To stabilize the amplitude of the radio frequency (RF) signal, the target output amplitude of the RF signal is determined according to requirements. Based on the target output amplitude, a first threshold voltage V is determined. h Second threshold voltage V l For example, to maintain the amplitude of the RF output signal at around -20dBm, since the detector unit converts the RF signal into a DC signal, the target output amplitude is converted into a corresponding voltage. The voltage value corresponding to the target output amplitude is related to the parameters of the components in the detector unit. That is, if the target output amplitude is -20dBm, assuming the DC voltage output by the detector unit is... When the voltage is 2.1V, the first threshold voltage is taken. Second threshold voltage In actual testing, V det Connected to two comparators and The control signal is compared with the final output control integral parameters.

[0052] The dynamic RC integrator unit includes resistor R30, capacitor C22, resistor R25, resistor R26, transistor Q1, transistor Q2, resistor R27, resistor R28, follower U6, and integrator U7.

[0053] The structure of the dynamic RC integrator unit is as follows: the inverting input of integrator U7 has three inputs. One input is connected to the emitter of transistor Q1 via resistor R25, the collector of transistor Q1 is connected to the output of the detector unit, and the base of transistor Q1 is connected to resistor R20 of the dual threshold comparator unit. The second input is connected to the output of the detector unit via resistor R30. The third input is connected to the emitter of transistor Q2 via resistor R26, the collector of transistor Q2 is connected to the output of the detector unit, and the base of transistor Q2 is connected to resistor R21 of the dual threshold comparator unit. The output of integrator U7 is connected to the power supply via capacitor C22 and resistor R30. The non-inverting input of integrator U7 is connected to the output of follower U6. The output of integrator U7 is connected to two outputs via resistor R27: one is connected to the non-inverting input of follower U6, and the other is grounded via resistor R28. The inverting input of follower U6 is connected to the output of follower U6. The positive power supply terminals of both the follower U6 and the integrator U7 are connected to a power source, while the negative power supply terminals of both the follower U6 and the integrator U7 are grounded.

[0054] like Figure 6 As shown, the signal feedback unit includes resistor R32, capacitor C23, capacitor C24, and inductor L3.

[0055] The structure of the signal feedback unit is as follows: the input terminal of the signal feedback unit is connected to two outputs after the resistor R32. One output is connected to the output terminal of the signal feedback unit through the inductor L3, and the other output is grounded through the capacitor C23. A capacitor C24 is connected in parallel across the two ends of the capacitor C23.

[0056] Detector unit U1 converts the amplitude of the radio frequency output RFOUT into a DC voltage. , One path is connected to the non-inverting input of U2, and the first threshold voltage is connected to the inverting input of U2. The comparison is performed by connecting one line to the non-inverting input of U5 and comparing it with the second threshold voltage of the inverting input of U5. Comparison. When When the amplitude of the output signal from the detector unit is too high, U2 outputs a high level, Q1 conducts, U5 outputs a low level, and Q2 is cut off. Resistors R25 and R30 are connected in parallel, slightly reducing the value of the integrating resistor to dynamically adjust the integrating time constant, achieving a fast response. When the amplitude is too high, the gain is slowly adjusted to avoid excessive signal suppression and prevent overshoot. Specifically, the value of R25 is much larger than that of R30. When the amplitude of the output signal from the detector unit is too low, U2 outputs a low level, Q1 is cut off, U5 outputs a high level, Q2 is turned on, and resistors R26 and R30 are connected in parallel, reducing the value of the integrating resistor and dynamically adjusting the integration time. This achieves rapid response, quickly boosts gain, and avoids signal loss. The value of R26 is significantly smaller than that of R30. This means that as long as the detector output voltage exceeds the threshold, dynamic integration is triggered, achieving precise and rapid response, ensuring the system neither overshoots nor responds too quickly. Simultaneously, the integration output, after passing through a resistor network composed of resistors R27 and R28 and buffered by follower U6, is fed back to the non-inverting input of integrator U7, achieving adaptive reference voltage input, automatically compensating for drift, and resulting in a more precise stabilization point.

[0057] Dynamic RC integrator output voltage V tune :

[0058]

[0059] when At that time, the output voltage V tune As time decreases, the output current also decreases, the resistance of PIN diodes D1 and D2 increases, the attenuation of the RF signal increases, and the amplitude of the RF output signal decreases accordingly, until... The points reach a stable state; when As the output control voltage increases over time, the output current also increases, the resistance of PIN diodes D1 and D2 decreases, the attenuation of the RF signal decreases, and the amplitude of the RF output signal increases accordingly, until... The integral reaches a stable state; this cycle continues until a stable control voltage and current are output, thereby compensating for fluctuations and ensuring that the RF output amplitude remains stable at the target value. This avoids signal transmission obstacles caused by increases or decreases in the input signal amplitude.

[0060] Calculate the gain of the entire link of this utility model and measure the fluctuation range of the radio frequency signal. For example, when the fluctuation range of the radio frequency signal is -40dBm to 0dBm, the total attenuation of the three π-type attenuators is 8dB, and the total gain of the two-stage amplifier composed of amplifier U3 and amplifier U4 is about 38dB. When the input signal amplitude is -40dBm, in order to achieve a target output amplitude of -20dBm, the total attenuation of the PIN diodes needs to reach 10dB [-20-(-40-8+38)]; when the input signal amplitude is 0dBm, in order to achieve a target output amplitude of -20dBm, the total attenuation of the PIN diodes needs to reach 50dB [-20-(0-8+38)], so the total attenuation of the PIN diodes needs to meet an adjustable range of greater than 10dB to 50dB.

[0061] like Figure 7 As shown, the coordinate axes are logarithmic, and the curve exhibits an approximately linear descent; the expression conforms to a power function relationship. =k· Where k is the proportionality coefficient and n is the decay exponent. Fitting is performed by selecting points from the graph, for example, point 1 (…). =0.1mA, ≈1000Ω) and point 2 ( =10mA, (≈10Ω), thus obtaining an approximate expression for the curve. ≈ (Units: Ω, mA, T) A =+25℃), when the forward bias current is 0.01mA, the RF resistance value The RF resistance is approximately 10000Ω when the forward bias current is 100mA. Approximately 1Ω, according to the attenuation formula A=20lg( ), (where A is the attenuation amount, The input signal voltage. (For the output voltage), assuming the PIN diode impedance is... The load impedance is R L =50Ω, then , respectively and Substituting into the attenuation formula, we obtain the maximum attenuation of a single tube. 46.06dB, minimum attenuation =0.17dB.

[0062] The attenuation of the PIN attenuation unit needs to meet an adjustable range of greater than 10dB to 50dB. Therefore, two PIN diodes (D1 and D2) need to be connected in series so that the theoretical adjustable range of attenuation can reach 0.34dB to 92.12dB, which meets the attenuation requirements.

[0063] like Figure 8 As shown, the y-axis scale is 20mV / div. Figure 8 The displayed value is the peak voltage. Actual testing verified that when the input signal amplitude is between -40dBm and 0dBm, the target output amplitude can reach approximately -20dBm using this circuit.

[0064] The attenuation of the π-type attenuator, the gain of amplifiers U3 and U4, and the type and quantity of PIN diodes can be set according to specific requirements.

Claims

1. A radio frequency signal amplitude adjustment circuit, characterized in that, include: The signal conditioning and matching unit, connected to the PIN attenuation unit, is used to improve signal quality and transmission efficiency; The PIN attenuation unit is connected to the signal conditioning and matching unit, the detection unit, and the signal feedback unit, respectively, and is used to adjust the amplitude of the input signal and output the radio frequency signal. The detection unit is connected to the PIN attenuation unit and the dual threshold comparison unit respectively, and is used to convert the signal output by the PIN attenuation unit into a DC signal; The dual threshold comparison unit is connected to the detection unit and the dynamic RC integrator unit respectively, and is used to generate control signals for the integral parameters and reduce the jitter of the output signal. The dynamic RC integrator unit is connected to the dual threshold comparison unit and the signal feedback unit respectively, and is used to integrate the output signal of the detector unit with the adaptive reference input signal to generate a control voltage. as well as The signal feedback unit is connected to the dynamic RC integration unit and the PIN attenuation unit respectively. It is used for filtering and preventing signal leakage, and outputs to the PIN attenuation unit.

2. The radio frequency signal amplitude adjustment circuit according to claim 1, characterized in that, The structure of the dual threshold comparison unit is as follows: the non-inverting input of comparator U2 and the inverting input of comparator U5 are both connected to the input signal of the dual threshold comparison unit; the inverting input of comparator U2 is connected to the first threshold voltage; and the output of comparator U2 is connected to the dynamic RC integration unit via resistor R20. The non-inverting input of comparator U5 is connected to a second threshold voltage. The output of comparator U5 is connected to a dynamic RC integrator unit through resistor R21. The first threshold voltage is greater than the voltage corresponding to the target output amplitude, and the second threshold voltage is less than the voltage corresponding to the target output amplitude.

3. The radio frequency signal amplitude adjustment circuit according to claim 2, characterized in that, The structure of the dynamic RC integrator unit is as follows: the inverting terminal of integrator U7 is connected to three inputs. One input is connected to the emitter of transistor Q1 via resistor R25. The collector of transistor Q1 is connected to the output of the detector unit, and the base of transistor Q1 is connected to resistor R20 of the dual threshold comparator unit. A second input is connected to the output of the detector unit via resistor R30. The third input is connected to the emitter of transistor Q2 via resistor R26. The collector of transistor Q2 is connected to the detector unit. The output terminals of the unit are connected together. The base of the transistor Q2 is connected to the resistor R21 of the dual threshold comparator unit. The output terminal of the integrator U7 is connected to the power supply through capacitor C22 and resistor R30. The non-inverting input of the integrator U7 is connected to the output terminal of the follower U6. The output terminal of the integrator U7 is connected to two outputs after passing through resistor R27. One output is connected to the non-inverting input of the follower U6, and the other output is grounded through resistor R28. The inverting input of the follower U6 is connected to the output terminal of the follower U6.

4. The radio frequency signal amplitude adjustment circuit according to claim 1, characterized in that, The structure of the signal conditioning and matching unit is as follows: pin 1 of amplifier U3 is connected to the input terminal of the signal conditioning and matching unit via capacitor C19, the first π-type attenuator, and capacitor C15; pin 3 of amplifier U3 has two outputs, one of which is connected to the power supply via inductor L1; the other is connected to pin 1 of amplifier U4 via capacitor C17, the second π-type attenuator, and capacitor C18; pin 3 of amplifier U4 has two outputs, one of which is connected to the power supply via inductor L2; the other is connected to the output terminal of the signal conditioning and matching unit via capacitor C16.

5. The radio frequency signal amplitude adjustment circuit according to claim 1, characterized in that, The structure of the PIN attenuation unit is as follows: pin 1 of PIN diode D1 is connected to the input signal of the PIN attenuation unit via capacitor C21, the third π-type attenuator, and capacitor C20; pin 2 of PIN diode D2 is connected to pin 1 of PIN diode D2; pin 2 of PIN diode D2 has two outputs, one of which is connected to the output terminal of the PIN attenuation unit, and the other is grounded via inductor L4; pin 1 of PIN diode D1 is connected to the output terminal of the signal feedback unit.

6. The radio frequency signal amplitude adjustment circuit according to claim 1, characterized in that, The detector unit is structured as follows: pin 1 of detector U1 is connected to the input terminal of the detector unit via capacitor C4; pin 3 of detector U1 is connected to capacitor C5 and then split into two paths, one path is connected to the input signal of the detector unit via resistor R1, and the other path is grounded; pin 4 of detector U1 is connected to the output of the detector unit via resistor R3, and pin 5 of detector U1 is connected to the output terminal of the detector unit; pin 6 of detector U1 is grounded via resistor R2; pin 7 of detector U1 is split into two paths, one path is connected to the power supply, and the other path is grounded via capacitor C1, with capacitor C2 connected in parallel across capacitor C1; pin 8 of detector U1 is grounded via capacitor C3.

7. The radio frequency signal amplitude adjustment circuit according to claim 1, characterized in that, The structure of the signal feedback unit is as follows: the input terminal of the signal feedback unit is connected to two outputs after the resistor R32. One output is connected to the output terminal of the signal feedback unit through the inductor L3, and the other output is grounded through the capacitor C23. A capacitor C24 is connected in parallel across the two ends of the capacitor C23.

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