An amplitude stabilization method and level control device for radio power metering

Abstract

This invention discloses an amplitude stabilization method and a level control device for radio power metering. The method measures the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the absence of an AC signal using a single-arm current source circuit; and measures the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the presence of an AC signal using the same circuit. The coupling degree C and the target power value P are obtained through a human-machine interface module. g The DC voltage without AC signal, the DC voltage with AC signal, the coupling degree, and the target power value are input to the signal processing module, which outputs the target power characterization voltage U. g and the current power characterization voltage U p Using an integral limiting circuit to limit U g and U p It is converted into a modulation voltage and sent to a control signal source or an electrically adjustable attenuator to achieve stable control of radio power and improve the accuracy and stability of power measurement.

Description

Technical Field

[0001] This invention relates to the field of metrology and testing technology, and specifically to an amplitude stabilization method and level control device for radio power measurement. Background Technology

[0002] In the field of radio power metering, especially in medium and high power metering scenarios, the stability of signal power is crucial to the accuracy of metering. The national metrology technical document "JJF 1386-2013 Medium Power Meter Calibration Specification" clearly requires the use of amplitude stabilizers, i.e. level control devices, to construct medium power calibration systems in order to ensure the accuracy and reliability of power measurements.

[0003] Existing level control devices mainly employ diode detectors or thermistor power detectors. Diode detectors are significantly affected by the environment and have poor long-term stability, making it difficult to meet the requirements of high-precision metering. While single-thermistor level control devices, such as the Tigan 1805 model, use thermistors to improve stability, they are based on a voltage-excited Wheatstone bridge. Newer thermistor power detectors, due to changes in the ceramic substrate structure, experience a significant increase in zero-point balance voltage, rendering the original drive circuit inadequate for their operation. Furthermore, the use of two-wire thermistor measurement and single-thermistor designs limits measurement accuracy and lacks thermal dissipation compensation. Therefore, achieving stable and accurate level control in radio power metering, overcoming the shortcomings of existing technologies in drive capability, measurement accuracy, and power compensation, and improving the overall performance of radio power metering has become an urgent problem to be solved. To address this, a method for amplitude stabilization and a level control device for radio power metering are proposed. Summary of the Invention

[0004] The purpose of this invention is to provide an amplitude stabilization method and a level control device for radio power metering, so as to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] An amplitude stabilization method in radio power metering includes the following steps:

[0007] S1. In an environment without AC signal, two single-arm current source circuits are used to measure the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector, respectively, to obtain the DC voltage of the working thermistor Rt1 without AC signal and the DC voltage of the compensation thermistor Rt2 without AC signal.

[0008] S2. In an environment with an AC signal, use two single-arm current source circuits to measure the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector, respectively, to obtain the DC voltage of the working thermistor Rt1 with an AC signal and the DC voltage of the compensation thermistor Rt2 with an AC signal.

[0009] S3. Obtain the coupling degree C and target power value through the human-computer interaction module in the host. The coupling degree C and the target power value The DC voltage without AC signal of the working thermistor Rt1, the DC voltage without AC signal of the compensation thermistor Rt2, the DC voltage with AC signal of the working thermistor Rt1, and the DC voltage with AC signal of the compensation thermistor Rt2 are input into the signal processing module, and the target power characterization voltage and the current power characterization voltage are output.

[0010] S4. Through the integral limiting circuit, the target power characterization voltage and the current power characterization voltage are converted into a modulation voltage, and the modulation voltage is sent to the control signal source or the electrically adjustable attenuator.

[0011] Preferably, the single-arm current source circuit includes a voltage output port U, a +15V DC power supply VCC, a -15V DC power supply VEE, a standard resistor Rs with a resistance of 200Ω, an internal thermistor Rt of the power detector, a start-up auxiliary resistor Rc, operational amplifier peripheral resistors R101, R102, R103, R104, R105 and R106, voltage-controlled current source control transistors Q101 and Q102, a single-pole single-throw control switch SPST, instrumentation amplifiers A101 and A102 and operational amplifiers A103 and A104;

[0012] The single-arm current source circuit includes a voltage output port U, a DC power supply VCC, a DC power supply VEE, a standard resistor Rs, an internal thermistor Rt of the power detector, a start-up auxiliary resistor Rc, operational amplifier peripheral resistors R101, R102, R103, R104, R105 and R106, voltage-controlled current source control transistors Q101 and Q102, a single-pole single-throw control switch SPST, instrumentation amplifiers A101 and A102 and operational amplifiers A103 and A104;

[0013] The DC power supply VCC is connected to the collector of the voltage-controlled current source transistor Q101 via a wire. The base of the voltage-controlled current source transistor Q101 is connected to the output terminal of operational amplifier A103 and one end of the operational amplifier's peripheral resistor R101 via wires. The inverting input terminal of operational amplifier A103 is connected to the other end of the operational amplifier's peripheral resistor R101 and one end of the operational amplifier's peripheral resistor R102 via wires. The non-inverting input terminal of operational amplifier A103 is connected to one end of the operational amplifier's peripheral resistor R103 via a wire. The other end of the operational amplifier peripheral resistor R102 is connected via wires to the output terminal of instrumentation amplifier A102 and one end of operational amplifier peripheral resistor R104, respectively. The other end of the operational amplifier peripheral resistor R103 is connected via wires to the output terminal of instrumentation amplifier A101, one end of operational amplifier peripheral resistor R105, and voltage output port U, respectively. The other end of the operational amplifier peripheral resistor R104 is connected via wires to the non-inverting input terminal of operational amplifier A104. The other end of the operational amplifier peripheral resistor R105 is connected via wires to operational amplifier A102. The inverting input terminal of 04 is connected to one end of the operational amplifier peripheral resistor R106. The other end of the operational amplifier peripheral resistor R106 is connected to the output terminal of operational amplifier A104 and the base of voltage-controlled current source transistor Q102 via wires. The collector of voltage-controlled current source transistor Q102 is connected to DC power supply VEE via wires. The emitter of voltage-controlled current source transistor Q102 is connected to one end of the internal thermistor Rt of the power detector, one end of the start-up auxiliary resistor Rc, and the inverting input terminal of instrumentation amplifier A102 via wires. At the phase input terminal, the other end of the starting auxiliary resistor Rc is connected to one end of the single-pole single-throw control switch SPST via a wire. The other end of the thermistor Rt inside the power detector is connected to the other end of the single-pole single-throw control switch SPST, the non-inverting input terminal of instrumentation amplifier A102, the inverting input terminal of instrumentation amplifier A101, and one end of the standard resistor Rs via wires. The other end of the standard resistor Rs is connected to the non-inverting input terminal of instrumentation amplifier A101 and the emitter of voltage-controlled current source transistor Q101 via a wire.

[0014] Preferably, the method of using two single-arm current source circuits to measure the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector is as follows:

[0015] The working thermistor Rt1 and the compensation thermistor Rt2 in the power detector are measured using two single-arm current source circuits within the main unit. The working thermistor Rt1 and the compensation thermistor Rt2 are connected to the single-arm current source circuits using a four-wire method. The initial resistance values ​​of the working thermistor Rt1 and the compensation thermistor Rt2 are... If the single-arm current source circuit cannot be directly driven, close the SPST switch in the single-arm current source circuit to connect the working thermistor Rt1 and the compensation thermistor Rt2 in parallel with their respective starting auxiliary resistors Rc, thereby reducing the equivalent resistance. To facilitate the normal operation of the single-arm current source circuit, after closing the SPST switch in the single-arm current source circuit for 1 second, the initial resistance values ​​of the working thermistor Rt1 and the compensation thermistor Rt2 drop to [value missing]. Disconnect the SPST switch, and the single-arm current source circuit enters the normal operating mode. Under the normal operating mode, the voltages on the working thermistor Rt1 and the compensation thermistor Rt2, as well as their respective standard resistors Rs, are measured by instrumentation amplifiers A101 and A102. After feedback adjustment by operational amplifiers A103 and A104, and voltage-controlled current source control transistors Q101 and Q102, the voltages on the working thermistor Rt1, the compensation thermistor Rt2, and their respective standard resistors Rs are equal, resulting in a stable DC voltage.

[0016] Under conditions without AC signal, the DC voltage of the working thermistor Rt1 without AC signal is obtained through a single-arm current source circuit. and the DC voltage without AC signal of the compensating thermistor Rt2 ;

[0017] Under conditions with an AC signal, the DC voltage of the working thermistor Rt1 with an AC signal is obtained through a single-arm current source circuit. And the compensation thermistor Rt2 has AC signal DC voltage .

[0018] Preferably, the coupling degree C and the target power value are... The method involves inputting the DC voltage of the working thermistor Rt1 (without AC signal), the DC voltage of the compensation thermistor Rt2 (without AC signal), the DC voltage of the working thermistor Rt1 (with AC signal), and the DC voltage of the compensation thermistor Rt2 (with AC signal) into a signal processing module, and then outputting the target power characterization voltage and the current power characterization voltage.

[0019] For coupling degree C and target power value The target power characterization voltage is obtained by calculating using the target power characterization voltage formula. ;

[0020] The formula for representing the target power voltage is:

[0021] ;

[0022] Where C is the coupling degree. This represents the target power value, where k is the proportionality coefficient, and its value ranges from [0.4, 0.5]. The target power characterizes the voltage;

[0023] DC voltage without AC signal for the operating thermistor Rt1 The working thermistor Rt1 has an AC signal and a DC voltage. The DC substitution power of the AC signal on the thermistor is obtained by calculating using the formula for DC substitution power of the thermistor. ;

[0024] DC voltage without AC signal for compensating thermistor Rt2 And the compensation thermistor Rt2 has AC signal DC voltage Calculated using the DC substitution power formula for thermistors.

[0025] The thermal conductivity power received on the thermistor at the compensation end is obtained ;

[0026] The formula for the DC substitution power of the thermistor is:

[0027]

[0028] in, It is the DC substitution power of the AC signal on the thermistor. Or the thermal conduction power received by the thermistor at the compensation terminal , It is the DC voltage of the working thermistor Rt1 without AC signal. Or compensate for the DC voltage of the thermistor Rt2 without AC signal. , The working thermistor Rt1 has an AC signal and a DC voltage. Or compensate for the AC signal DC voltage of the thermistor Rt2 ;

[0029] The DC substitution power of the AC signal obtained on the thermistor The thermal conduction power received by the thermistor at the compensation terminal The current power characterization voltage is obtained by calculating using the general formula for current power characterization voltage. ;

[0030] The general formula for the current power characterization voltage is:

[0031] ;

[0032] in, This represents the current power voltage, where k is a proportionality coefficient with a value range of [0.4, 0.5]. It is the heat conduction power received by the thermistor at the compensation end. It is the DC substitution power of the AC signal on the thermistor.

[0033] Preferably, the current power characterization voltage formula is used when the resistance values ​​of both the compensation thermistor Rt2 and the working thermistor Rt1 are... At this time, the general formula for current power characterization voltage is converted into a simplified formula for current power characterization voltage;

[0034] The general formula for the current power characterization voltage is:

[0035] ;

[0036] in, This represents the current power voltage, where k is a proportionality coefficient with a value range of [0.4, 0.5]. It is the DC voltage without AC signal for the working thermistor Rt1. The thermistor Rt1 has an AC signal and a DC voltage. It is the DC voltage without AC signal for compensating the thermistor Rt2. It is the DC voltage with AC signal for compensating the thermistor Rt2;

[0037] The current simplified formula for power characterization voltage is implemented through a simplified analog circuit for power characterization voltage.

[0038] Preferably, the simplified analog circuit for power characterization voltage includes a first analog-to-digital converter, a second analog-to-digital converter, a first digital-to-analog converter, a second digital-to-analog converter, operational amplifiers A201, A202, A203, A204, A205, A206, A207, A208, and A209, multipliers M201, M202, M203, and M204, and the current power characterization voltage. Output port, current DC voltage of thermistor Rt1 The input port and thermistor Rt2 currently have no AC signal and no DC voltage. Input port;

[0039] The multipliers M201, M202, M203 and M204 have a first input interface, a second input interface and an output interface;

[0040] The operational amplifier A209 has an output interface, an input interface A205, an input interface A206, an input interface A207, and an input interface A208.

[0041] The operational amplifiers A201, A202, A203, A204, A205, A206, A207 and A208 have input interfaces and output interfaces;

[0042] The current DC voltage of the thermistor Rt1 The input ports are connected via wires to the input interface of the first analog-to-digital converter (ADC) and the input interface of operational amplifier A202, respectively. The output interface of the first ADC is connected via wires to its input interface. The output interface of the first ADC is connected via wires to the input interface of operational amplifier A201. The output interface of operational amplifier A201 is connected via wires to the first and second input interfaces of multiplier M201, respectively. The output interface of multiplier M201 is connected via wires to the input interface of operational amplifier A205. The input interface of operational amplifier A205 is connected via wires to the A205 input interface of operational amplifier A209. The output interface of operational amplifier A202 is connected via wires to the first and second input interfaces of multiplier M202, respectively. The output interface of multiplier M202 is connected via wires to the input interface of operational amplifier A206, and the input interface of operational amplifier A206 is connected via wires to the A206 input interface of operational amplifier A209. The current DC voltage of the thermistor Rt2 is... The input ports are connected via wires to the input interfaces of the second analog-to-digital converter (ADC) and operational amplifier A204, respectively. The output interface of the second ADC is connected via a wire to its input interface. The output interface of the second ADC is also connected via a wire to the input interface of operational amplifier A203. The output interface of operational amplifier A203 is connected via a wire to the first and second input interfaces of multiplier M203, respectively. The output interface of multiplier M203 is connected via a wire to the input interface of operational amplifier A207, and the input interface of operational amplifier A207 is connected via a wire to the A207 input interface of operational amplifier A209. The output interface of operational amplifier A204 is connected via a wire to the first and second input interfaces of multiplier M204, respectively. The output interface of multiplier M204 is connected via a wire to the input interface of operational amplifier A208, and the input interface of operational amplifier A208 is connected via a wire to the A208 input interface of operational amplifier A209. The output interface of operational amplifier A209 is connected via a wire to the current power rating voltage. Output port.

[0043] Preferably, the integral limiting circuit includes a DC power supply VCC, operational amplifiers A301 and A302, a single-pole double-throw switch SPDT, a resistor R301, a non-polarized capacitor C301, diodes Z301 and Z302, a current power characterization voltage input port, a target power characterization voltage input port, and a modulation voltage output port.

[0044] The target power characterization voltage The input port is connected to the inverting input of operational amplifier A301 via a wire, and the current power characterization voltage is... The input port is connected to the non-inverting input terminal of operational amplifier A301 via a wire. The output terminal of operational amplifier A301 is connected to the normally closed terminal of single-pole double-throw switch SPDT via a wire. The DC power supply VCC is connected to the normally open terminal of single-pole double-throw switch SPDT via a wire. The common terminal of single-pole double-throw switch SPDT is connected to one end of resistor R301 via a wire. The other end of resistor R301 is connected to the positive terminal of non-polarized capacitor C301 and the inverting input terminal of operational amplifier A302 via wires. The non-inverting input terminal of operational amplifier A302 is grounded via a wire. The output terminal of operational amplifier A302 is connected to the negative terminal of non-polarized capacitor C301 and the modulation voltage via wires. The output port is connected to the anode of diode Z301, the cathode of diode Z301 is connected to the cathode of diode Z302 via a wire, and the anode of diode Z302 is grounded via a wire.

[0045] Preferably, the method of converting the target power characterization voltage and the current power characterization voltage into a modulation voltage using an integral limiting circuit is as follows:

[0046] The operational amplifier A301 in the integration and limiting circuit will use the current power characteristic voltage. and target power characteristic voltage The difference is amplified by 10,000 times to improve steady-state sensitivity. A single-pole double-throw (SPDT) switch is used to switch the operating state. When the steady-state mode is activated, the SPDT switch in the integration limiting circuit is switched to its normally closed position. The SPDT switch is connected to operational amplifier A301, and the modulation voltage is obtained through the integration limiting circuit. When the amplitude stabilization state is off, switch the single-pole double-throw (SPDT) switch in the integral limiting circuit to its normally open position. The SPDT switch is connected to the DC power supply VCC. The integrator circuit will output the modulated voltage. Pull back to the negative maximum value.

[0047] Preferably, the level control device in the radio power metering includes a power detector and a host. The power detector includes a working thermistor Rt1, a compensation thermistor Rt2, a heating resistor Rh, and a temperature measuring resistor Rt3. The host includes two single-arm current sources, a temperature control module, a temperature measuring module, a signal processing module, an integral limiting module, and a human-machine interaction module.

[0048] The single-arm current source is connected to the thermistor inside the power detector via a four-wire method.

[0049] The temperature control module is used to control the temperature of the power detector to keep Rt1 and Rt2 in a relatively stable working state.

[0050] The temperature measurement module is used to measure the internal temperature of the power detector and to determine whether the power detector is in a stable working state by the temperature change rate.

[0051] The human-computer interaction module is used for inputting and outputting parameters, including the coupling degree C and the target power value. The output parameter is the display modulation voltage. .

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. This invention uses a single-arm current source circuit to replace the traditional voltage-excited Wheatstone bridge. A feedback loop consisting of voltage-controlled current source transistors Q101 and Q102 and operational amplifiers A103 and A104 is used to achieve stable current excitation for the thermistor. Addressing the issue of increased zero-point balance voltage in novel thermistor power detectors due to changes in the ceramic substrate structure, the auxiliary resistor Rc and the single-pole single-throw control switch SPST are used to reduce the equivalent resistance in the initial measurement phase, ensuring normal current source drive. This effectively solves the problem that existing drive circuits cannot adapt to thermistors with high zero-point balance voltages, improving the device's compatibility with different types of thermistor power detectors.

[0054] 2. This invention uses a four-wire method to connect the working thermistor Rt1 and the compensation thermistor Rt2 into a single-arm current source circuit, significantly reducing the impact of wire resistance on measurement accuracy. Compared with the existing two-wire method, it greatly reduces the interference of contact resistance and lead resistance. At the same time, the two single-arm current sources are used to independently measure the working thermistor Rt1 and the compensation thermistor Rt2 respectively. Combined with the temperature sensing resistor Rt3 and the temperature control module to accurately control the temperature of the power detector, the influence of ambient temperature fluctuations on the measurement results is eliminated, realizing high-precision measurement of the thermistor DC voltage and providing a reliable data foundation for subsequent power calculation.

[0055] 3. This invention innovatively adopts a dual-thermistor design. Through a signal processing module, the DC voltage of the two thermistors is differentially calculated under conditions with and without AC signals. This effectively compensates for the heat dissipation power of the ceramic substrate inside the power detector. Specifically, the working thermistor Rt1 is used to sense the heat generated by the radio power, and the compensation thermistor Rt2 is used to monitor the influence of environmental heat conduction. The DC substitution power of the two thermistors is calculated by combining the main path radio power formula with the coupling degree C, eliminating the defect that a single thermistor cannot compensate for heat dissipation. This improves the calculation accuracy of the main path radio power P and solves the problem of large power measurement deviation in complex environments in existing single thermistor designs. Attached Figure Description

[0056] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is a flowchart of the steps of the present invention;

[0058] Figure 2 This is a schematic diagram of the level control device of the present invention;

[0059] Figure 3 This is a schematic diagram of the single-arm current source circuit of the present invention;

[0060] Figure 4 This is a schematic diagram of the simplified analog circuit for power characterization voltage according to the present invention;

[0061] Figure 5 This is a schematic diagram of the integral limiting circuit of the present invention. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0063] Examples, such as Figure 1 As shown, an amplitude stabilization method in radio power metering includes the following steps:

[0064] S1. In an environment without AC signal, two single-arm current source circuits are used to measure the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector, respectively, to obtain the DC voltage of the working thermistor Rt1 without AC signal and the DC voltage of the compensation thermistor Rt2 without AC signal.

[0065] S2. In an environment with an AC signal, use two single-arm current source circuits to measure the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector, respectively, to obtain the DC voltage of the working thermistor Rt1 with an AC signal and the DC voltage of the compensation thermistor Rt2 with an AC signal.

[0066] S3. Obtain the coupling degree C and target power value through the human-computer interaction module in the host. The coupling degree C and the target power value The DC voltage without AC signal of the working thermistor Rt1, the DC voltage without AC signal of the compensation thermistor Rt2, the DC voltage with AC signal of the working thermistor Rt1, and the DC voltage with AC signal of the compensation thermistor Rt2 are input into the signal processing module, and the target power characterization voltage and the current power characterization voltage are output.

[0067] S4. Through the integral limiting circuit, the target power characterization voltage and the current power characterization voltage are converted into a modulation voltage, and the modulation voltage is sent to the control signal source or the electrically adjustable attenuator.

[0068] Furthermore, the working principle of the present invention will be illustrated below through embodiments:

[0069] Assuming we are building a level control device for radio power metering, we prepare the power detector section, ensuring that its internal working thermistor Rt1 and compensation thermistor Rt2 are installed correctly, and connect the heating resistor Rh and the temperature measuring resistor Rt3. For the main unit, we set up two single-arm current sources, a temperature control module, a temperature measuring module, a signal processing module, an integral limiting module, and a human-machine interaction module, and ensure that the wiring between each module is correct. The single-arm current sources are connected to the thermistors inside the power detector using a four-wire method.

[0070] Turn on the device power and start the temperature control module to heat the power detector. The internal temperature of the power detector is monitored in real time through the temperature measuring resistor Rt3. When the temperature reaches a stable state and the temperature change rate is within a very small range, such as the temperature change not exceeding 0.1℃ every 10 minutes, the power detector is considered to have reached a stable operating temperature environment.

[0071] Using the two single-arm current source circuits inside the main unit, the working thermistor Rt1 and the compensation thermistor Rt2 were measured respectively. The initial resistance values ​​of the working thermistor Rt1 and the compensation thermistor Rt2 were... Since the single-arm current source circuit cannot be directly driven, the SPST switch in the single-arm current source circuit is closed, which connects the working thermistor Rt1 and the compensation thermistor Rt2 in parallel with their respective starting auxiliary resistors Rc. This facilitates the normal operation of the single-arm current source circuit. After closing the SPST switch for 1 second, the resistance values ​​of the working thermistor Rt1 and the compensation thermistor Rt2 drop to [value missing]. Disconnecting the SPST switch allows the single-arm current source circuit to enter normal operating mode. In normal operating mode, instrumentation amplifiers A101 and A102 measure the voltage across the working thermistor Rt1, the compensation thermistor Rt2, and their respective standard resistors Rs. Feedback adjustment via operational amplifiers A103 and A104, and voltage-controlled current source transistors Q101 and Q102, ensures that the voltages across the working thermistor Rt1, the compensation thermistor Rt2, and their respective standard resistors Rs are equal, thus obtaining a stable DC voltage—the DC voltage of the working thermistor Rt1 without an AC signal. and the DC voltage without AC signal of the compensating thermistor Rt2 .

[0072] After the power detector receives an AC signal, the DC voltage of the working thermistor Rt1 without an AC signal is obtained by repeatedly disconnecting the SPST switch. and the DC voltage without AC signal of the compensating thermistor Rt2 The steps involve again using a single-arm current source circuit to measure the working thermistor Rt1 and the compensation thermistor Rt2, obtaining the DC voltage with AC signal of the working thermistor Rt1. And the compensation thermistor Rt2 has AC signal DC voltage .

[0073] The coupling degree C is input through the human-machine interface module in the host machine. Assuming C equals -20dB, the target power value is... Set to 100mW. The target power characterization voltage is calculated using the target power characterization voltage formula. The voltage is 0.45V; based on the formula for the DC substitution power of a thermistor, calculate the DC substitution power of the AC signal on the thermistor. The thermal conduction power received by the thermistor at the compensation terminal Assuming the measurement yields It is 3V. It is 2.5V. 2V The voltage is 1.95V, and the standard resistor Rs has a resistance of 200Ω. It is 0.01375W. The value is 0.0009875W; using the general formula for current power characterization voltage, the current power characterization voltage is calculated. The voltage is 6.631875V. Since the resistance of both the compensation thermistor Rt2 and the working thermistor Rt1 is 200Ω, it can also be verified by calculation using the simplified formula for power characterization voltage. The value was 6.631875V, which is consistent with the result.

[0074] Characterize the target power with voltage and current power characterization voltage Input integration limiting circuit. The operational amplifier A301 in the integration limiting circuit amplifies the difference between the two values ​​by a factor of 10,000 to improve steady-state sensitivity. When the steady-state mode is enabled, the single-pole double-throw switch SPDT in the integration limiting circuit is switched to its normally closed position. At this time, the modulation voltage is obtained through the integration limiting circuit. Assuming the amplified voltage difference is processed by an integration and limiting circuit to obtain the modulation voltage. The modulated voltage is 2V. The signal is input to a control signal source or an electrically adjustable attenuator to achieve stable control of the radio power. In practical applications, if there is a deviation between the current power and the target power, the modulation voltage... The system will adjust accordingly to control the signal source or electrically adjustable attenuator, stabilizing the output power at the target power value. nearby.

[0075] The main channel radio power P and modulation voltage are monitored and recorded in real time through the human-computer interaction module. Operators can intuitively see the current power changes and the modulation voltage adjustment process, which facilitates the monitoring and optimization of the entire radio power metering system.

[0076] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method of amplitude stabilization in radio power metering, characterized by, The method comprises the following steps: S1, in the environment without AC signal, using two single-arm current source circuits to respectively measure the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector, obtaining the DC voltage of the working thermistor Rt1 without AC signal and the DC voltage of the compensation thermistor Rt2 without AC signal; S2, in the environment with AC signal, using two single-arm current source circuits to respectively measure the DC voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector, obtaining the DC voltage of the working thermistor Rt1 with AC signal and the DC voltage of the compensation thermistor Rt2 with AC signal; S3, obtaining the coupling degree C and the target power value through a human-computer interaction module in the host , the coupling degree C, the target power value , the AC-free signal DC voltage of the working thermistor Rt1, the AC-free signal DC voltage of the compensation thermistor Rt2, the AC signal DC voltage of the working thermistor Rt1 and the AC signal DC voltage of the compensation thermistor Rt2 are input into a signal processing module, and the target power representation voltage and the current power representation voltage are output. S4, through the integral limiting circuit, the target power characteristic voltage and the current power characteristic voltage are converted into the modulation voltage, and the modulation voltage is input to the control signal source or the electrically controlled attenuator.

2. The method of claim 1, wherein, The single-arm current source circuit comprises a voltage output port U, a DC power supply VCC, a DC power supply VEE, a standard resistor Rs, an internal thermistor Rt of the power detector, a starting auxiliary resistor Rc, peripheral resistors R101, R102, R103, R104, R105 and R106 of an operational amplifier, current-controlled triodes Q101 and Q102, a single-pole single-throw control switch SPST, instrument amplifiers A101 and A102, and operational amplifiers A103 and A104. The direct current power supply VCC is connected to the collector of the voltage-controlled current source control transistor Q101 through a wire, the base of the voltage-controlled current source control transistor Q101 is connected to the output end of the operational amplifier A103 and one end of the operational amplifier peripheral resistor R101 through wires respectively, the inverting input end of the operational amplifier A103 is connected to the other end of the operational amplifier peripheral resistor R101 and one end of the operational amplifier peripheral resistor R102 through wires respectively; the non-inverting input end of the operational amplifier A103 is connected to one end of the operational amplifier peripheral resistor R103 through a wire, the other end of the operational amplifier peripheral resistor R102 is connected to the output end of the instrument amplifier A102 and one end of the operational amplifier peripheral resistor R104 through wires respectively, the other end of the operational amplifier peripheral resistor R103 is connected to the output end of the instrument amplifier A101, one end of the operational amplifier peripheral resistor R105 and the voltage output port U through wires respectively, the other end of the operational amplifier peripheral resistor R104 is connected to the non-inverting input end of the operational amplifier A104 through a wire, the other end of the operational amplifier peripheral resistor R105 is connected to the inverting input end of the operational amplifier A104 and one end of the operational amplifier peripheral resistor R106 through wires respectively, the other end of the operational amplifier peripheral resistor R106 is connected to the output end of the operational amplifier A104 and the base of the voltage-controlled current source control transistor Q102 through wires respectively, the collector of the voltage-controlled current source control transistor Q102 is connected to the direct current power supply VEE through a wire, the emitter of the voltage-controlled current source control transistor Q102 is connected to one end of the power detector internal thermistor Rt, one end of the starting auxiliary resistor Rc and the inverting input end of the instrument amplifier A102 through wires respectively, the other end of the starting auxiliary resistor Rc is connected to one end of the single-pole single-throw control switch SPST through a wire, the other end of the power detector internal thermistor Rt is connected to the other end of the single-pole single-throw control switch SPST, the non-inverting input end of the instrument amplifier A102, the inverting input end of the instrument amplifier A101 and one end of the standard resistor Rs through wires respectively, the other end of the standard resistor Rs is connected to the non-inverting input end of the instrument amplifier A101 and the emitter of the voltage-controlled current source control transistor Q101 through wires respectively.

3. The method of claim 2, wherein the amplitude stabilization is performed by, The method for measuring the direct current voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector by using two single-arm current source circuits: The single-pole single-throw control switch SPST in the two single-arm current source circuits is closed for 1s, the single-pole single-throw control switch SPST in the two single-arm current source circuits which is closed for 1s is opened, and the direct current voltage of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector is measured by using the two single-arm current source circuits respectively.

4. The method of claim 3, wherein the amplitude stabilization is performed by, The coupling degree C, the target power value The AC signal-free DC voltage of the working thermistor Rt1, the AC signal-free DC voltage of the compensation thermistor Rt2, the AC signal-bearing DC voltage of the working thermistor Rt1, and the AC signal-bearing DC voltage of the compensation thermistor Rt2 are input into the signal processing module, and the target power characteristic voltage and the current power characteristic voltage are output. to the coupling degree C and the target power value the target power characteristic voltage is obtained by the target power characteristic voltage formula calculation ; The direct current voltage without alternating current signal to the working thermistor Rt1 The direct current voltage with alternating current signal to the working thermistor Rt1 The direct current replacement power of the alternating current signal on the thermistor is obtained by the direct current replacement power formula calculation of the thermistor ; Direct current voltage without alternating signal to compensate thermistor Rt2 Direct current voltage with alternating signal to compensate thermistor Rt2 Calculation by thermistor direct current replacement power formula, Compensating for heat transfer power experienced by a thermistor ; The obtained AC signal on the thermistor is replaced by DC power and compensates the heat conduction power received by the thermistor The current power characteristic voltage is calculated by the general formula of voltage characteristic ; The target power characterization voltage formula is: ; Wherein, k is a proportional coefficient, and the value range of k is [0.4, 0.5]; The direct current replacement power formula of the thermistor is: ; wherein is the DC replacement power for the AC signal on the thermistor or compensates for the heat conduction power experienced by the thermistor is the DC voltage without AC signal for the working thermistor Rt1 or compensates for the DC voltage without AC signal for the thermistor Rt2 is the DC voltage with AC signal for the working thermistor Rt1 or compensates for the DC voltage with AC signal for the thermistor Rt2 ;​​ The current power representation voltage general formula is: .

5. The method of claim 4, wherein the amplitude stabilization is performed by, The current power characteristic voltage formula, when the resistance values of the compensation thermistor Rt2 and the working thermistor Rt1 are The current power characteristic voltage formula is converted into a current power characteristic voltage simplified formula. The current power characteristic voltage simplification formula is realized through a power characteristic voltage simplification analog circuit; The current power characteristic voltage simplification formula is: 。 6. The method of claim 5, wherein the amplitude stabilization is performed by, The power characterization voltage simplified analog circuit comprises a first analog-to-digital converter, a second analog-to-digital converter, a first digital-to-analog converter, a second digital-to-analog converter, operational amplifiers A201, A202, A203, A204, A205, A206, A207, A208 and A209, multipliers M201, M202, M203 and M204, a current power characterization voltage An output port, a thermistor Rt1 current DC voltage input port and a thermistor Rt2 current DC voltage input port; The multiplier M201, M202, M203 and M204 have a first input interface, a second input interface and an output interface; The operational amplifier A209 has an output interface, an A205 input interface, an A206 input interface, an A207 input interface and an A208 input interface; The operational amplifier A201, A202, A203, A204, A205, A206, A207 and A208 have an input interface and an output interface; The current DC voltage input port of the thermistor Rt1 is connected to the input interface of the first analog-to-digital converter and the input interface of the operational amplifier A202 through wires respectively, the output interface of the first analog-to-digital converter is connected to the input interface of the first digital-to-analog converter through wires, the output interface of the first digital-to-analog converter is connected to the input interface of the operational amplifier A201 through wires, the output interface of the operational amplifier A201 is connected to the first input interface and the second input interface of the multiplier M201 through wires respectively, the output interface of the multiplier M201 is connected to the input interface of the operational amplifier A205 through wires; the output interface of the operational amplifier A205 is connected to the A205 input interface of the operational amplifier A209 through wires; the output interface of the operational amplifier A202 is connected to the first input interface and the second input interface of the multiplier M202 through wires respectively, the output interface of the multiplier M202 is connected to the input interface of the operational amplifier A206 through wires, the output interface of the operational amplifier A206 is connected to the A206 input interface of the operational amplifier A209 through wires, the current DC voltage input port of the thermistor Rt2 is connected to the input interface of the second analog-to-digital converter and the input interface of the operational amplifier A204 through wires respectively, the output interface of the second analog-to-digital converter is connected to the input interface of the second digital-to-analog converter through wires, the output interface of the second digital-to-analog converter is connected to the input interface of the operational amplifier A203 through wires, the output interface of the operational amplifier A203 is connected to the first input interface and the second input interface of the multiplier M203 through wires respectively, the output interface of the multiplier M203 is connected to the input interface of the operational amplifier A207 through wires, the output interface of the operational amplifier A207 is connected to the A207 input interface of the operational amplifier A209 through wires; the output interface of the operational amplifier A204 is connected to the first input interface and the second input interface of the multiplier M204 through wires respectively, the output interface of the multiplier M204 is connected to the input interface of the operational amplifier A208 through wires, the output interface of the operational amplifier A208 is connected to the A208 input interface of the operational amplifier A209 through wires, the output interface of the operational amplifier A209 is connected to the current power characteristic voltage output port through wires.

7. The method of claim 6, wherein the amplitude stabilization is performed in a radio power meter. The integral limiting circuit comprises a DC power supply VCC, operational amplifiers A301 and A302, a single-pole double-throw switch SPDT, a resistor R301, a non-polar capacitor C301, diodes Z301 and Z302, a current power representation voltage input port, target power representation voltage input port and modulation voltage output port; The target power characteristic voltage input port is connected with the inverting input terminal of the operational amplifier A301 through a wire, the current power characteristic voltage input port is connected with the non-inverting input terminal of the operational amplifier A301 through a wire, the output terminal of the operational amplifier A301 is connected with the normally closed terminal of the single-pole double-throw switch SPDT through a wire, the direct current power supply VCC is connected with the normally open terminal of the single-pole double-throw switch SPDT through a wire, the common terminal of the single-pole double-throw switch SPDT is connected with one end of the resistor R301 through a wire, the other end of the resistor R301 is connected with the positive pole of the non-polarity capacitor C301 and the inverting input terminal of the operational amplifier A302 through wires respectively, the non-inverting input terminal of the operational amplifier A302 is grounded through a wire, the output terminal of the operational amplifier A302 is connected with the negative pole of the non-polarity capacitor C301 and the modulation voltage output port and the anode of the diode Z301 through wires respectively, the cathode of the diode Z301 is connected with the cathode of the diode Z302 through a wire, the anode of the diode Z302 is grounded through a wire.

8. The method of claim 7, wherein the amplitude stabilization is performed by a radio power meter. The method for converting the target power characteristic voltage and the current power characteristic voltage into a modulation voltage through the integral limiting circuit: The single-pole double-throw switch (SPDT) in the integral limiting circuit is switched to the normally closed end, and the integral limiting circuit switched to the normally closed end through the switch converts the target power characteristic voltage and the current power characteristic voltage into a modulation voltage .

9. A level control device in radio power metering, characterized by The method for realizing the amplitude stabilization in the radio power measurement according to any one of claims 1 to 8, wherein the level control device in the radio power measurement comprises a power detector and a host computer, the power detector comprises a working thermistor Rt1, a compensation thermistor Rt2, a heating resistor Rh and a temperature measuring resistor Rt3, and the host computer comprises two single-arm current sources, a temperature control module, a temperature measuring module, a signal processing module, an integral limiting module and a human-computer interaction module; The single-arm current sources are connected to the thermistors in the power detector through a four-wire method, and the thermistors comprise the working thermistor Rt1 and the compensation thermistor Rt2; The working thermistor Rt1 is electrically connected to the first single-arm current source through a four-wire method, and the voltage output end of the first single-arm current source is electrically connected to the first input end of the signal processing module; The compensation thermistor Rt2 is electrically connected to the second single-arm current source through a four-wire method, and the voltage output end of the second single-arm current source is electrically connected to the second input end of the signal processing module; The temperature measuring resistor Rt3 is electrically connected to the signal acquisition end of the temperature measuring module, and the signal output end of the temperature measuring module is electrically connected to the third input end of the signal processing module; The first output end of the human-computer interaction module is electrically connected to the fourth input end of the signal processing module, the second output end of the human-computer interaction module is electrically connected to the fifth input end of the signal processing module, and the first input end of the human-computer interaction module is electrically connected to the first output end of the signal processing module; The second output end of the signal processing module is electrically connected to the first input end of the integral limiting module, and the third output end of the signal processing module is electrically connected to the second input end of the integral limiting module; The second output end of the integral limiting module is used for being electrically connected to an external signal source or an electrically tunable attenuator, and the first output end of the integral limiting module is electrically connected to the second input end of the human-computer interaction module.

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