Amplitude stabilizing method and level control device in radio power metering

Abstract

The invention discloses an amplitude stabilizing method and a level control device in radio power metering, and the method comprises the steps: measuring the AC-signal-free DC voltage of a working thermistor Rt1 and a compensation thermistor Rt2 through a single-arm current source circuit in an AC-signal-free environment; in an alternating current signal environment, a single-arm current source circuit is used for measuring alternating current signal direct current voltage of a working thermistor Rt1 and a compensation thermistor Rt2; a coupling degree C and a target power value Pg are obtained through a man-machine interaction module, the non-alternating-current signal direct-current voltage, the alternating-current signal direct-current voltage, the coupling degree and the target power value are input into a signal processing module, and a target power representation voltage Ug and a current power representation voltage Up are output; ug and Up are converted into modulation voltages by using an integral amplitude limiting circuit, and the modulation voltages are transmitted to a control signal source or an electrically controlled attenuator, so that the stable control of radio power is realized, and the accuracy and stability of power metering are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metrology and testing, and particularly to a method for stabilizing amplitude in radio power metrology and a level control device. Background Art

[0002] In the field of radio power metrology, especially in the scenario of medium and high power metrology, the stability of signal power is crucial for metrology accuracy. The national metrology technical document "JJF 1386-2013 Calibration Specification for Medium Power Meters" clearly requires the use of an amplitude stabilizer, that is, a level control device to construct a medium power calibration system to ensure the accuracy and reliability of power measurement.

[0003] Existing level control devices mainly adopt diode detection type or thermistor type power detectors. The diode detection type is significantly affected by the environment and has poor long-term stability, making it difficult to meet the requirements of high-precision metrology. For the single thermistor type level control device represented by the 1805 type of Titanium Gan Company, although the thermistor is used to improve stability, the device is based on a Wheatstone bridge excited by voltage. Due to the change in the ceramic matrix structure of the new thermistor type power detector, the zero balance voltage has increased significantly, making the original drive circuit unable to meet its working requirements. At the same time, the device uses the two-wire method to measure the thermistor and the single thermistor design, resulting in limited measurement accuracy and lack of heat dissipation compensation. Therefore, how to achieve stable and accurate level control in radio power metrology, overcome the deficiencies of the existing technology in driving ability, measurement accuracy, and power compensation, and improve the overall performance of radio power metrology has become an urgent problem to be solved. For this reason, a method for stabilizing amplitude in radio power metrology and a level control device are proposed. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for stabilizing amplitude in radio power metrology and a level control device to solve the problems raised in the above background art.

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

[0006] A method for stabilizing amplitude in radio power metrology includes the following steps:

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

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

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

[0010] S4. Through the integral limiting circuit, convert the target power characterization voltage and the current power characterization voltage into a modulation voltage, and input the modulation voltage to the control signal source or the electrically tunable 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 value of 200Ω, a thermistor Rt inside the power detector, a starting 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, a thermistor Rt inside the power detector, a starting 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 control transistor Q101 through a wire. The base of the voltage-controlled current source control transistor Q101 is connected to the output terminal of the operational amplifier A103 and one end of the resistor R101 around the operational amplifier through wires. The inverting input terminal of the operational amplifier A103 is connected to the other end of the resistor R101 around the operational amplifier and one end of the resistor R102 around the operational amplifier through wires; the non-inverting input terminal of the operational amplifier A103 is connected to one end of the resistor R103 around the operational amplifier through a wire. The other end of the resistor R102 around the operational amplifier is connected to the output terminal of the instrumentation amplifier A102 and one end of the resistor R104 around the operational amplifier through wires. The other end of the resistor R103 around the operational amplifier is connected to the output terminal of the instrumentation amplifier A101, one end of the resistor R105 around the operational amplifier, and the voltage output port U through wires. The other end of the resistor R104 around the operational amplifier is connected to the non-inverting input terminal of the operational amplifier A104 through a wire. The other end of the resistor R105 around the operational amplifier is connected to the inverting input terminal of the operational amplifier A104 and one end of the resistor R106 around the operational amplifier through wires. The other end of the resistor R106 around the operational amplifier is connected to the output terminal of the operational amplifier A104 and the base of the voltage-controlled current source control transistor Q102 through wires. The collector of the voltage-controlled current source control transistor Q102 is connected to the DC power supply VEE through a wire. The emitter of the voltage-controlled current source control 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 the instrumentation amplifier A102 through wires. The other end of the start-up 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 internal thermistor Rt of the power detector is connected to the other end of the single-pole single-throw control switch SPST, the non-inverting input terminal of the instrumentation amplifier A102, the inverting input terminal of the instrumentation amplifier A101, and one end of the standard resistor Rs through wires. The other end of the standard resistor Rs is connected to the non-inverting input terminal of the instrumentation amplifier A101 and the emitter of the voltage-controlled current source control transistor Q101 through wires.

[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 respectively:

[0015] Through two single-arm current source circuits in the host, the working thermistor Rt1 and the compensating thermistor Rt2 in the power detector are measured respectively. The working thermistor Rt1 and the compensating thermistor Rt2 are connected to the single-arm current source circuit by the four-wire method. The initial resistance values of the working thermistor Rt1 and the compensating thermistor Rt2 are 6 kΩ to 7 kΩ, and the single-arm current source circuit cannot directly drive. At this time, the SPST switch in the single-arm current source circuit is closed, so that the working thermistor Rt1 and the compensating thermistor Rt2 are connected in parallel with their respective starting auxiliary resistors Rc, reducing the equivalent resistance value by 1.5 KΩ, facilitating the normal operation of the single-arm current source circuit. The SPST switch in the single-arm current source circuit is closed for 1 s, and the initial resistance values of the working thermistor Rt1 and the compensating thermistor Rt2 drop to 200 Ω. The SPST switch is disconnected, and the single-arm current source circuit enters the normal working mode. Under the conditions of the normal working mode, the voltages on the working thermistor Rt1 and the compensating thermistor Rt2, as well as their respective corresponding standard resistors Rs, are measured by the instrumentation amplifiers A101 and A102 respectively, and through the feedback regulation of the operational amplifiers A103 and A104, and the current control triodes Q101 and Q102 of the voltage-controlled current source, the voltages on the working thermistor Rt1, the compensating thermistor Rt2 and their respective corresponding standard resistors Rs are made equal, obtaining a stable DC voltage;

[0016] Under the condition of an environment without an AC signal, the DC voltage U without an AC signal of the working thermistor Rt1 is obtained through the single-arm current source circuit 10 and the DC voltage U without an AC signal of the compensating thermistor Rt2 20 ;

[0017] Under the condition of an environment with an AC signal, the DC voltage U with an AC signal of the working thermistor Rt1 is obtained through the single-arm current source circuit 11 and the DC voltage U with an AC signal of the compensating thermistor Rt2 21 .

[0018] Preferably, the method of inputting the coupling degree C, the target power value P g , the DC voltage without an AC signal of the working thermistor Rt1, the DC voltage without an AC signal of the compensating thermistor Rt2, the DC voltage with an AC signal of the working thermistor Rt1 and the DC voltage with an AC signal of the compensating thermistor Rt2 into the signal processing module and outputting the target power characterization voltage and the current power characterization voltage:

[0019] For the coupling degree C and the target power value P g , calculate through the target power characterization voltage formula to obtain the target power characterization voltage U g ;

[0020] The target power characterization voltage formula is:

[0021] U g = 1000k10 0.1C P g ;

[0022] where C is the coupling degree, P g is the target power value, k is the proportionality coefficient, and its value range is [0.4, 0.5], U g is the voltage characterizing the target power;

[0023] For the DC voltage U 10 without AC signal of the working thermistor Rt1 and the DC voltage U 11 with AC signal of the working thermistor Rt1, calculate through the DC substitution power formula of the thermistor to obtain the DC substitution power P Rt1 of the AC signal on the thermistor;

[0024] For the DC voltage U 20 without AC signal of the compensating thermistor Rt2 and the DC voltage U 21 with AC signal of the compensating thermistor Rt2, calculate through the DC substitution power formula of the thermistor to obtain the heat conduction power P Rt2 received on the compensating thermistor;

[0025] The DC substitution power formula of the thermistor is:

[0026]

[0027] where P Rt is the DC substitution power P Rt1 of the AC signal on the thermistor or the heat conduction power P Rt2 received on the compensating thermistor, U0 is the DC voltage U 10 without AC signal of the working thermistor Rt1 or the DC voltage U 20 without AC signal of the compensating thermistor Rt2, U1 is the DC voltage U 11 with AC signal of the working thermistor Rt1 or the DC voltage U 21 with AC signal of the compensating thermistor Rt2;

[0028] Calculate the obtained DC substitution power P Rt1 of the AC signal on the thermistor and the heat conduction power P Rt2 received on the compensating thermistor through the general formula of the current power characterizing voltage to obtain the current power characterizing voltage U p ;

[0029] The general formula of the current power characterizing voltage is:

[0030] Up = 1000k(P Rt1 + P Rt2 ));

[0031] Among them, U p is the current power characterization voltage, k is the proportionality coefficient, and its value range is [0.4, 0.5], P Rt2 is the heat conduction power received by the thermistor at the compensation end, P Rt1 is the DC substitution power of the AC signal on the thermistor.

[0032] Preferably, for the formula of the current power characterization voltage, when the resistance values of the compensation thermistor Rt2 and the working thermistor Rt1 are both 200 Ω, the general formula of the current power characterization voltage is converted into the simplified formula of the current power characterization voltage;

[0033] The general formula of the current power characterization voltage is:

[0034]

[0035] Among them, U p is the current power characterization voltage, k is the proportionality coefficient, and its value range is [0.4, 0.5], U 10 is the DC voltage without AC signal of the working thermistor Rt1, U 11 is the DC voltage with AC signal of the working thermistor Rt1, U 20 is the DC voltage without AC signal of the compensation thermistor Rt2, U 21 is the DC voltage with AC signal of the compensation thermistor Rt2;

[0036] The simplified formula of the current power characterization voltage is implemented by a simplified analog circuit for power characterization voltage.

[0037] 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, the output port of the current power characterization voltage U p the input port of the current DC voltage U1 of the thermistor Rt1 and the input port of the current DC voltage U2 without AC signal of the thermistor Rt2;

[0038] The multipliers M201, M202, M203, and M204 have a first input interface, a second input interface, and an output interface;

[0039] 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;

[0040] The operational amplifiers A201, A202, A203, A204, A205, A206, A207, and A208 have input interfaces and output interfaces;

[0041] The input port of the current DC voltage U1 of the thermistor Rt1 is respectively connected to the input interface of the first analog-to-digital converter and the input interface of the operational amplifier A202 through wires. The output interface of the first analog-to-digital converter is connected to the input interface of the first analog-to-digital converter through a wire. The output interface of the first analog-to-digital converter is connected to the input interface of the operational amplifier A201 through a wire. The output interface of the operational amplifier A201 is respectively connected to

[0042] the first input interface and the second input interface of the multiplier M201. The output interface of the multiplier M201 is connected to the input interface of the operational amplifier A205 through a wire. The input interface of the operational amplifier A205 is connected to the A205 input interface of the operational amplifier A209 through a wire. The output interface of the operational amplifier A202 is respectively connected to the first input interface and the second input interface of the multiplier M202. The output interface of the multiplier M202 is connected to the input interface of the operational amplifier A206 through a wire. The input interface of the operational amplifier A206 is connected to the A206 input interface of the operational amplifier A209 through a wire. The input port of the current DC voltage U2 of the thermistor Rt2 is respectively connected to the input interface of the second analog-to-digital converter and the input interface of the operational amplifier A204 through wires. The output interface of the second analog-to-digital converter is connected to the input interface of the second analog-to-digital converter through a wire. The output interface of the second analog-to-digital converter is connected to the input interface of the operational amplifier A203 through a wire. The output interface of the operational amplifier A203 is respectively connected to the first input interface and the second input interface of the multiplier M203. The output interface of the multiplier M203 is connected to the input interface of the operational amplifier A207 through a wire. The input interface of the operational amplifier A207 is connected to the A207 input interface of the operational amplifier A209 through a wire. The output interface of the operational amplifier A204 is respectively connected to the first input interface and the second input interface of the multiplier M204. The output interface of the multiplier M204 is connected to the input interface of the operational amplifier A208 through a wire. The input interface of the operational amplifier A208 is connected to the A208 input interface of the operational amplifier A209 through a wire. The output interface of the operational amplifier A209 is connected to the current power characterization voltage U p 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-polar 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 U g The input port is connected to the inverting input terminal of the operational amplifier A301 through a wire, and the current power characterization voltage U p The input port is connected to the non-inverting input terminal of the operational amplifier A301 through a wire. The output terminal of the operational amplifier A301 is connected to the normally closed terminal of the single-pole double-throw switch SPDT through a wire. The DC power supply VCC is connected to 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 to one end of the resistor R301 through a wire. The other end of the resistor R301 is connected to the positive electrode of the non-polar capacitor C301 and the inverting input terminal of the operational amplifier A302 through a wire. 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 to the negative electrode of the non-polar capacitor C301, the modulation voltage U m Output port and the anode of the diode Z301. The cathode of the diode Z301 is connected to the cathode of the diode Z302 through a wire. The anode of the diode Z302 is grounded through a wire.

[0045] Preferably, the method for converting the target power characterization voltage and the current power characterization voltage into a modulation voltage through the integral limiting circuit:

[0046] The operational amplifier A301 of the integral limiting circuit amplifies the difference between the current power characteristic voltage U p and the target power characteristic voltage U g by 10,000 times to improve the steady-state sensitivity. The single-pole double-throw switch SPDT is used to switch the working state. When the amplitude stabilization state is turned on, the switch of the single-pole double-throw switch SPDT in the integral limiting circuit is switched to the normally closed terminal. The single-pole double-throw switch SPDT is connected to the operational amplifier A301, and the modulation voltage U m is obtained through the integral limiting circuit. When the amplitude stabilization state is turned off, the switch of the single-pole double-throw switch SPDT in the integral limiting circuit is switched to the normally open terminal. The single-pole double-throw switch SPDT is connected to the DC power supply VCC, and the integral circuit pulls back the output modulation voltage U m to the negative maximum value.

[0047] Preferably, the level control device in radio power measurement includes a power detector and a host. The power detector includes a working thermistor Rt1, a compensating 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 integration and limiting module, and a human-computer interaction module;

[0048] The single-arm current source is connected to the thermistor in the power detector by the four-wire method;

[0049] The temperature control module is used to control the temperature and heat the power detector so that Rt1 and Rt2 are in a relatively stable working state;

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

[0051] The human-computer interaction module is used to input and output parameters. The input parameters include the coupling degree C and the target power value P g , and the output parameter is the displayed modulation voltage U m .

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

[0053] 1. The present invention uses a single-arm current source circuit to replace the traditional voltage-excited Wheatstone bridge. Through the feedback loop composed of the voltage-controlled current source control transistors Q101, Q102 and the operational amplifiers A103, A104, a stable current excitation for the thermistor is realized. Aiming at the problem of the increase in the zero balance voltage caused by the change in the ceramic matrix structure of the new thermistor type power detector, through the cooperation of the starting auxiliary resistor Rc and the single-pole single-throw control switch SPST, the equivalent resistance is reduced in the initial stage of measurement to ensure the normal drive of the current source, effectively solving the problem that the existing drive circuit cannot adapt to the thermistor with a high zero balance voltage, and improving the compatibility of the device with different types of thermistor power detectors.

[0054] 2. The present invention connects the working thermistor Rt1 and the compensating thermistor Rt2 to the single-arm current source circuit by the four-wire method, significantly reducing the influence of the wire resistance on the measurement accuracy. Compared with the existing two-wire method measurement, the interference of the contact resistance and the lead resistance is greatly reduced. At the same time, two single-arm current sources are used to independently measure the working thermistor Rt1 and the compensating thermistor Rt2 respectively, and combined with the accurate control of the temperature of the power detector by the temperature measuring resistor Rt3 and the temperature control module, the influence of the environmental temperature fluctuation on the measurement result is eliminated, realizing the high-precision measurement of the DC voltage of the thermistor, and providing a reliable data basis for the subsequent power calculation.

[0055] 3. The innovation of the present invention adopts a dual-thermistor design. By using a signal processing module to perform differential calculation on the DC voltages of the two under AC signal presence and absence environments, it can effectively compensate for the thermal dissipation power of the ceramic substrate inside the power detector. Specifically, the working thermistor Rt1 is used to sense the heat generated by radio power, and the compensation thermistor Rt2 is used to monitor the influence of environmental heat conduction. The DC substitution power of the two is calculated through the main-path radio power formula in combination with the coupling degree C, eliminating the defect that a single thermistor cannot compensate for thermal dissipation, improving the calculation accuracy of the main-path radio power P, and solving the problem of large power measurement deviation of the existing single-thermistor design in complex environments.

[0056] Explanatory drawings of the specification

[0057] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0058] Figure 1 Is the step flowchart of the present invention;

[0059] Figure 2 Is the structural schematic diagram of the level control device of the present invention;

[0060] Figure 3 Is the structural schematic diagram of the single-arm current source circuit of the present invention;

[0061] Figure 4 Is the structural schematic diagram of the power characterization voltage simplified analog circuit of the present invention;

[0062] Figure 5 Is the structural schematic diagram of the integral limiter circuit of the present invention. Detailed implementation manners

[0063] To make the objectives, technical solutions, and advantages of the present invention clearer, the following will describe the technical solutions of the present invention in detail. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. All other implementation manners obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention belong to the scope protected by the present invention.

[0064] Embodiment, as Figure 1 shown, a method for amplitude stabilization in radio power measurement includes the following steps:

[0065] S1. In an environment without an AC signal, use two single-arm current source circuits to measure the DC voltages of the working thermistor Rt1 and the compensating thermistor Rt2 in the power detector respectively, and obtain the DC voltage of the working thermistor Rt1 without an AC signal and the DC voltage of the compensating thermistor Rt2 without an AC signal;

[0066] S2. In an environment with an AC signal, use two single-arm current source circuits to measure the DC voltages of the working thermistor Rt1 and the compensating thermistor Rt2 in the power detector respectively, and obtain the DC voltage of the working thermistor Rt1 with an AC signal and the DC voltage of the compensating thermistor Rt2 with an AC signal;

[0067] S3. Obtain the coupling degree C and the target power value P through the human-machine interaction module in the host g , and input the coupling degree C, the target power value P g , the DC voltage of the working thermistor Rt1 without an AC signal, the DC voltage of the compensating thermistor Rt2 without an AC signal, the DC voltage of the working thermistor Rt1 with an AC signal, and the DC voltage of the compensating thermistor Rt2 with an AC signal into the signal processing module, and output the target power characterization voltage and the current power characterization voltage;

[0068] S4. Through the integration and limiting circuit, convert the target power characterization voltage and the current power characterization voltage into a modulation voltage, and input the modulation voltage to the control signal source or the electronic attenuator.

[0069] Furthermore, the working principle of the present invention is illustrated by the following embodiments:

[0070] Suppose to construct a level control device in radio power measurement, prepare the power detector part, ensure that the internal working thermistor Rt1 and the compensating thermistor Rt2 are properly installed, connect the heating resistor Rh and the temperature measuring resistor Rt3, the host part, set up 2 single-arm current sources, a temperature control module, a temperature measuring module, a signal processing module, an integration and limiting module, and a human-machine interaction module, and ensure that the wiring between the modules is correct. The single-arm current source is connected to the thermistor in the power detector by the four-wire method.

[0071] Turn on the device power supply, start the temperature control module to heat the power detector, and monitor the internal temperature of the power detector 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 does not exceed 0.1 °C every 10 minutes, it is considered that the power detector reaches a stable working temperature environment.

[0072] Two single-arm current source circuits in the host are used to measure the working thermistor Rt1 and the compensation thermistor Rt2 respectively. The initial resistance values of the working thermistor Rt1 and the compensation thermistor Rt2 are in the range of 6 kΩ to 7 kΩ, and the single-arm current source circuit cannot directly drive them. At this time, by closing the SPST switch in the single-arm current source circuit, the working thermistor Rt1 and the compensation thermistor Rt2 are respectively connected in parallel with their respective starting auxiliary resistors Rc, which is convenient for the normal operation of the single-arm current source circuit. After closing the SPST switch for 1 s, the resistance values of the working thermistor Rt1 and the compensation thermistor Rt2 drop to 200 Ω. Then, the SPST switch is disconnected, and the single-arm current source circuit enters the normal working mode. Under the conditions of the normal working mode, the working thermistor Rt1 and the compensation thermistor Rt2, as well as the voltages on their respective corresponding standard resistors Rs, are measured by the instrumentation amplifiers A101 and A102 respectively, and through the feedback regulation of the operational amplifiers A103 and A104, and the current control transistors Q101 and Q102 of the voltage-controlled current source, the voltages on the working thermistor Rt1, the compensation thermistor Rt2 and their respective corresponding standard resistors Rs are made equal, so as to obtain a stable DC voltage, that is, the DC voltage U without AC signal of the working thermistor Rt1 10 and the DC voltage U without AC signal of the compensation thermistor Rt2 20 .

[0073] After the power detector is connected to the AC signal, repeat the steps of obtaining the DC voltage U without AC signal of the working thermistor Rt1 after disconnecting the SPST switch 10 and the DC voltage U without AC signal of the compensation thermistor Rt2 20 . Then, use the single-arm current source circuit to measure the working thermistor Rt1 and the compensation thermistor Rt2 again to obtain the DC voltage U with AC signal of the working thermistor Rt1 11 and the DC voltage U with AC signal of the compensation thermistor Rt2 21 .

[0074] Input the coupling degree C through the human-computer interaction module in the host. Assume that C is equal to -20 dB, and the target power value P g is set to 100 mW. According to the target power characterization voltage formula, calculate the target power characterization voltage U g to be 0.45 V; according to the DC substitution power formula of the thermistor, calculate the DC substitution power P Rt1 of the AC signal on the thermistor and the heat conduction power P Rt2 received by the thermistor at the compensation end respectively. Assume that the measured U 10 is 3 V, U 11 is 2.5 V, U 20 is 2 V, U 21is 1.95V, the resistance value of the standard resistor Rs is 200Ω, then P Rt1 is 0.01375W, P Rt2 is 0.0009875W; Using the current power characterization voltage general formula, the current power characterization voltage U p is 6.631875V. Since the resistance values of the compensation thermistor Rt2 and the working thermistor Rt1 are both 200Ω, it can also be calculated and verified through the simplified formula of the current power characterization voltage, U p is 6.631875V, and the results are consistent.

[0075] Input the target power characterization voltage U g and the current power characterization voltage U p into the integral limiting circuit. The operational amplifier A301 of the integral limiting circuit amplifies the difference between the two by 10,000 times to improve the steady-state sensitivity. When the amplitude stabilization state is turned on, the single-pole double-throw switch SPDT in the integral limiting circuit is switched to the normally closed end. At this time, the modulation voltage U m is obtained through the integral limiting circuit. Assuming that the amplified voltage difference is processed by the integral limiting circuit, the modulation voltage U m is 2V. This modulation voltage U m is input to the control signal source or the electrically tunable 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 U m will be adjusted accordingly, thereby controlling the signal source or the electrically tunable attenuator to make the output power stable near the target power value P g .

[0076] The main path radio power P and the modulation voltage U m are monitored and recorded in real time through the human-computer interaction module. The operator can intuitively see the change of the current power and the adjustment process of the modulation voltage, which is convenient for monitoring and optimizing the entire radio power measurement system.

[0077] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; modifying the technical solutions recorded in the foregoing embodiments, or equivalently replacing some of the technical features, does not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for amplitude stabilization in radio power measurement, characterized in that, It includes the following steps: S1. In an environment without an AC signal, use two single-arm current source circuits to respectively measure the DC voltages of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector, and obtain the DC voltage without an AC signal of the working thermistor Rt1 and the DC voltage without an AC signal of the compensation thermistor Rt2; S2. In an environment with an AC signal, use two single-arm current source circuits to respectively measure the DC voltages of the working thermistor Rt1 and the compensation thermistor Rt2 in the power detector, and obtain the DC voltage with an AC signal of the working thermistor Rt1 and the DC voltage with an AC signal of the compensation thermistor Rt2; S3. Obtain the coupling degree C and the target power value P through the human-machine interaction module in the host g , and input the coupling degree C, the target power value P g , 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 into the signal processing module, and output the target power characterization voltage and the current power characterization voltage; S4. Through an integration limiter circuit, convert the target power characterization voltage and the current power characterization voltage into a modulation voltage, and input the modulation voltage to the control signal source or the electronic attenuator.

2. The amplitude stabilization method in radio power measurement according to claim 1, characterized in that, 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 starting 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; The DC power supply VCC is connected to the collector of the voltage-controlled current-source control triode Q101 through a wire. The base of the voltage-controlled current-source control triode Q101 is respectively connected to the output terminal of the operational amplifier A103 and one end of the resistor R101 around the operational amplifier through wires. The inverting input terminal of the operational amplifier A103 is respectively connected to the other end of the resistor R101 around the operational amplifier and one end of the resistor R102 around the operational amplifier through wires; the non-inverting input terminal of the operational amplifier A103 is connected to one end of the resistor R103 around the operational amplifier through a wire. The other end of the resistor R102 around the operational amplifier is respectively connected to the output terminal of the instrumentation amplifier A102 and one end of the resistor R104 around the operational amplifier through wires. The other end of the resistor R103 around the operational amplifier is respectively connected to the output terminal of the instrumentation amplifier A101, one end of the resistor R105 around the operational amplifier, and the voltage output port U through wires. The other end of the resistor R104 around the operational amplifier is connected to the non-inverting input terminal of the operational amplifier A104 through a wire. The other end of the resistor R105 around the operational amplifier is respectively connected to the inverting input terminal of the operational amplifier A104 and one end of the resistor R106 around the operational amplifier through wires. The other end of the resistor R106 around the operational amplifier is respectively connected to the output terminal of the operational amplifier A104 and the base of the voltage-controlled current-source control triode Q102 through wires. The collector of the voltage-controlled current-source control triode Q102 is connected to the DC power supply VEE through a wire. The emitter of the voltage-controlled current-source control triode Q102 is respectively connected to one end of the internal thermistor Rt of the power detector, one end of the starting auxiliary resistor Rc, and the inverting input terminal of the instrumentation amplifier A102 through wires. 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 internal thermistor Rt of the power detector is respectively connected to the other end of the single-pole single-throw control switch SPST, the non-inverting input terminal of the instrumentation amplifier A102, the inverting input terminal of the instrumentation amplifier A101, and one end of the standard resistor Rs through wires. The other end of the standard resistor Rs is respectively connected to the non-inverting input terminal of the instrumentation amplifier A101 and the emitter of the voltage-controlled current-source control triode Q101 through wires.

3. The amplitude stabilization method in radio power measurement according to claim 2, wherein, The method of 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: Close the single-pole single-throw control switch SPST in the two single-arm current-source circuits for 1 s, then disconnect the single-pole single-throw control switch SPST in the two single-arm current-source circuits that have been closed for 1 s, and use the 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.

4. The amplitude stabilization method in radio power measurement according to claim 3, wherein The method of inputting the coupling degree C, the target power value P g , 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 into the signal processing module, and outputting the target power characterization voltage and the current power characterization voltage: For the coupling degree C and the target power value P g Through the calculation of the target power characterization voltage formula, the target power characterization voltage U is obtained g ; The DC voltage U of the working thermistor Rt1 without AC signal 10 and the DC voltage U of the working thermistor Rt1 with AC signal 11 are calculated through the DC substitution power formula of the thermistor to obtain the DC substitution power P of the AC signal on the thermistor Rt1 ; The DC voltage U without AC signal for compensating the thermistor Rt2 20 and the DC voltage U with AC signal for compensating the thermistor Rt2 21 are calculated through the DC substitution power formula of the thermistor to obtain the heat conduction power P received by the thermistor at the compensation end Rt2 ; The DC substitution power P of the AC signal on the obtained thermistor Rt1 and the heat conduction power P received by the thermistor at the compensation terminal Rt2 are calculated through the general formula of the current power characterization voltage, and the current power characterization voltage U is obtained p .

5. The amplitude stabilization method in radio power measurement according to claim 4, characterized in that When the resistance values of the compensation thermistor Rt2 and the working thermistor Rt1 are both 200 Ω, the current power characterization voltage general formula is converted into the current power characterization voltage simplified formula in the current power characterization voltage formula. The current power characterization voltage simplification formula is implemented by a power characterization voltage simplification analog circuit.

6. The amplitude stabilization method in radio power measurement according to claim 5, characterized in that, The power characterization voltage simplification analog circuit 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, a current power characterization voltage U output port, a current DC voltage U1 input port of the thermistor Rt1, and a current DC voltage U2 input port of the thermistor Rt2 without an AC signal. The multipliers 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 amplifiers A201, A202, A203, A204, A205, A206, A207, and A208 have an input interface and an output interface. The input port of the current DC voltage U1 of the thermistor Rt1 is respectively connected to the input interface of the first analog-to-digital converter and the input interface of the operational amplifier A202 through wires. The output interface of the first analog-to-digital converter is connected to the input interface of the first analog-to-digital converter through a wire. The output interface of the first analog-to-digital converter is connected to the input interface of the operational amplifier A201 through a wire. The output interface of the operational amplifier A201 is respectively connected to the first input interface and the second input interface of the multiplier M201 through wires. The output interface of the multiplier M201 is connected to the input interface of the operational amplifier A205 through a wire; the input interface of the operational amplifier A205 is connected to the A205 input interface of the operational amplifier A209 through a wire; the output interface of the operational amplifier A202 is respectively connected to the first input interface and the second input interface of the multiplier M202 through wires. The output interface of the multiplier M202 is connected to the input interface of the operational amplifier A206 through a wire. The input interface of the operational amplifier A206 is connected to the A206 input interface of the operational amplifier A209 through a wire. The input port of the current DC voltage U2 of the thermistor Rt2 is respectively connected to the input interface of the second analog-to-digital converter and the input interface of the operational amplifier A204 through wires. The output interface of the second analog-to-digital converter is connected to the input interface of the second analog-to-digital converter through a wire. The output interface of the second analog-to-digital converter is connected to the input interface of the operational amplifier A203 through a wire. The output interface of the operational amplifier A203 is respectively connected to the first input interface and the second input interface of the multiplier M203 through wires. The output interface of the multiplier M203 is connected to the input interface of the operational amplifier A207 through a wire. The input interface of the operational amplifier A207 is connected to the A207 input interface of the operational amplifier A209 through a wire; the output interface of the operational amplifier A204 is respectively connected to the first input interface and the second input interface of the multiplier M204 through wires. The output interface of the multiplier M204 is connected to the input interface of the operational amplifier A208 through a wire. The input interface of the operational amplifier A208 is connected to the A208 input interface of the operational amplifier A209 through a wire. The output interface of the operational amplifier A209 is connected to the current power characterization voltage U p output port.

7. The amplitude stabilization method in radio power measurement according to claim 6, characterized in that, 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-polar 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. The target power characterizes the voltage U g The input port is connected to the inverting input terminal of the operational amplifier A301 through a wire, and the current power characterizes the voltage U p The input port is connected to the non-inverting input terminal of the operational amplifier A301 through a wire. The output terminal of the operational amplifier A301 is connected to the normally closed terminal of the single-pole double-throw switch SPDT through a wire. The DC power supply VCC is connected to 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 to one end of the resistor R301 through a wire. The other end of the resistor R301 is respectively connected to the positive electrode of the non-polar capacitor C301 and the inverting input terminal of the operational amplifier A302 through a wire. The non-inverting input terminal of the operational amplifier A302 is grounded through a wire. The output terminal of the operational amplifier A302 is respectively connected to the negative electrode of the non-polar capacitor C301 and the modulation voltage U m The output port and the anode of the diode Z301. The cathode of the diode Z301 is connected to the cathode of the diode Z302 through a wire. The anode of the diode Z302 is grounded through a wire.

8. A method for amplitude stabilization in radio power measurement according to claim 7, characterized in that, The method for converting the target power characterization voltage and the current power characterization voltage into a modulation voltage through the integral limiting circuit: Switch the switch of the single-pole double-throw switch SPDT in the integral clipping circuit to the normally closed end. The integral clipping circuit switched to the normally closed end by the switch processes the target power characterization voltage U g and the current power characterization voltage U p and converts them into a modulation voltage U m .

9. A level control device in radio power measurement, characterized in that Implement the amplitude stabilization method in radio power measurement described in claims 1 to 8. The level control device in a radio power measurement 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. The single-arm current source is connected to the thermistor in the power detector by the four-wire method.

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