RU2520537C2 - Method to measure resonance structure characteristics and device for its implementation - Google Patents

Abstract

FIELD: measurement equipment.

SUBSTANCE: invention is related to the equipment for resonance radiotechnical measurements. The method involves generation of probing oscillation, its supply to the input and receipt from the output of a resonance structure, tuning of probing oscillation frequency in the measurement range corresponding to the resonance structure frequency band, registration of changes in its parameters according to which resonance frequency, resonance amplitude and Q-factor of the resonance structure are defined. The probing oscillation at the resonance structure is formed as double-frequency one with two components of equal amplitude with average frequency and initial difference frequency being less than or equal to the resonance structure frequency band. The resonance frequency of the resonance structure is measured at the time point when the modulation factor of the waveform envelope for beat signals between the probing oscillation components at the resonance structure output reaches the value 1, the resonance frequency is measured as equal to the value of the average frequency. The resonance amplitude of the resonance structure and the Q-factor of the resonance structure are calculated. Afterwards the initial difference frequency is changed with the average frequency of the probing oscillation remaining the same. Then the amplitude of the waveform envelope for beat signals between the probing oscillation components at the resonance structure output is measured. The device comprises a frequency tuned generator 1, a commutator 2, a detector 3 connected to a controller 4 for control and measurement of resonance structure characteristics, as well as sequentially connected units: the first transmission line 5, a resonance structure 6 and the second transmission line 7; the first commutator 2 output is connected to the input of the first transmission line 5, its second input - to the output of the second transmission line 7, and its second output - to the input of the detector 3. The frequency tuned generator 1, commutator 2 and controller 4 for control and measurement of resonance structure characteristics are fitted by control inputs/outputs combined into a control bus 8. A converter 9 of single-frequency oscillation to a double-frequency one is additionally introduced, the detector 3 is made as a detector of the envelope; the single-to-double frequency oscillation converter 9 is fitted by control inputs/outputs connected to the control bus 8, its input is connected to the output of the frequency tuned generator 1 and its output - to the first input of the commutator 2.

EFFECT: increased sensitivity and accuracy of measurements.

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Description

The technical solution relates to methods for resonant radio engineering measurements and devices for their implementation, in particular to methods for measuring the characteristics of resonant structures and devices for their implementation, such as resonant frequency, amplitude and quality factor, which are then used to calculate and monitor the complex permittivity of various materials, for example, in the process of curing thermosetting polymers. The basic element of devices that implement these measurement methods is a planar, linear or volume resonance sensor, which changes the resonant frequency, amplitude and quality factor, both after filling it with polymer, and due to the polymer acquiring new physicochemical properties during the process and corresponding changes in its electrophysical characteristics.

A known method for measuring the characteristics of resonant structures (see MSVenkatesh, GSVRanghatan. An overview of dielectric properties measuring techniques. Canadian Biosystems Engineering, v.47, 2005, pp.7.15-7.30), which provides a single-frequency probing oscillation, variable according to a certain law, in the measurement range from the output of the vector or scalar network analyzer to the input of the resonant structure, and take it at the input of the vector or scalar network analyzer reflected from or passed through the resonant structure, record changes in the parameters of the probe ring anija, which determine the resonant frequency f _p, U _P amplitude and quality factor Q of the resonant structure.

A device that implements this method comprises a scalar or vector network analyzer connected in series, a first transmission line, a resonant structure, and optionally, a second transmission line, when measuring the passage, while the output of the second transmission line is connected to the input of a scalar or vector network analyzer.

The disadvantage of these methods and devices is the need for measurements in the entire frequency band of the measurements, and not just the resonant structure, or when using special software in the frequency band necessary to determine the Q factor, the use of complex expensive scalar or vector network analyzers and broadband peak power detectors Microwave range. This leads to the fact that such devices are mainly laboratory. The spectral measurement of power is characterized by a small signal to noise ratio, due to both the wide band and the homodyne nature of the reception of the output oscillations of the resonant structure, as well as the presence of intense noise of a low-frequency peak detector. All this leads to the appearance of additional sources of errors in measuring the characteristics of resonant structures and a decrease in their accuracy as a whole.

The prototype of the invention - the method and the device is a method for measuring the characteristics of resonant structures (see US Patent No. 6,617,861 B1 "Device and method for measuring and monitoring the complex dielectric constant of materials", 324/637, IPC 8 G01R 27/04, 09/09/2003) , the method consists in generating a single-frequency sounding oscillation, applying it to the input and receiving from the output of the resonant structure, tuning the frequency of the sounding oscillation in the measurement range corresponding to the frequency band of the resonant structure, Changes of its parameters, which determine the resonant frequency f _p, U _P amplitude and quality factor Q of the resonant structure.

A device for implementing the method described above, selected as a prototype, contains a frequency-tunable generator connected to a switch, a detector connected to a controller for controlling and measuring the characteristics of the resonant structures, as well as a first transmission line, a resonant structure, and a second transmission line connected in series this, the first output of the switch is connected to the input of the first transmission line, its second input to the output of the second transmission line, and the second output to the detector input, tunable by the hour OTE generator, a switch, a detector controller and the control and measurement characteristics have resonance structures I / O interface, combined in a control bus

This method of measuring the characteristics of resonant structures and a device for its implementation have insufficient sensitivity and measurement accuracy. This method and device use less sophisticated equipment applicable in the production environment. However, in this case, a broadband microwave power detector is also used. Therefore, the disadvantage of this device is also that the spectral measurement of power is characterized by a small signal to noise ratio, due to both the wide band and the homodyne nature of the reception of the output oscillation of the resonant structure, and the presence of intense noise of the peak detector of low-frequency nature and low-frequency noise caused by fluctuations in the power of the generator and possible interference on transmission lines leading to the resonant structure. All this leads to a decrease in the sensitivity of measurements, the emergence of additional sources of measurement errors of the characteristics of resonant structures and a decrease in their accuracy in general.

The technical problem to be solved is to increase the sensitivity and accuracy of measurements.

The technical problem to be solved in the method for measuring the characteristics of resonant structures, which consists in generating a sounding oscillation, supplying it to the input and receiving from the output of the resonant structure, tuning the frequency of the sounding vibration in the measurement range corresponding to the frequency band of the resonant structure, recording changes in its parameters, which determine the resonant frequency f _p , the amplitude U _p and the quality factor Q of the resonant structure, is achieved by the fact that the probe oscillation at the input of the resonant structure The circuit breakers form two-frequency with two components of equal amplitude, respectively, at frequencies f ₁₁ and f ₁₂ with an average frequency f _C = (f ₁₁ + f ₁₂ ) / 2 and an initial difference frequency Δf _P1 = f ₁₁ -f ₁₂ less than or equal to the resonant passband structures, they tune the average frequency f _{C of the} probe oscillation, and during the tuning, the initial difference frequency Δf _{P1 is} left unchanged, the change in the average frequency of the probe oscillation f _C = (f ₁₁ + f ₁₂ ) / 2 is recorded and the modulation coefficient m of the envelope of the beat signal between constitute probing the oscillations at the output of the resonant structure, when the modulation coefficient reaches m = 1, measure the resonance frequency f _{P of the} resonant structure as equal to the average frequency f _C at a given time, and measure the corresponding envelope amplitude of the beat signal between the components of the probing vibration U ₁ at the output of the resonant structure, without further changing the average frequency f _{C of the} probe oscillation, the initial difference frequency Δf _{P1 is} changed by a certain value 2Δf, so that the frequency values are their probing oscillations become equal to f ₂₁ = f ₁₁ -Δf and f ₂₂ = f ₁₂ + Δf, respectively, and the difference frequency value Δf _P2 = Δf _P1 + 2Δf does not exceed the passband of the resonant structure, after which the amplitude of the beat signal envelope between the probing components is measured oscillations U ₂ at the output of the resonant structure, calculate the resonant amplitude U _{P of the} resonant structure by the expression

$$U_P=\sqrt{\left({\chi }^2{U}_{\mathrm{one}}^2-{\mathrm{<figure-callout\; id="2"\; label="U"\; filenames="00000009.png"\; state="\{\{state\}\}">U</figure-callout>}}_2^2\right)/\left({\chi }^2-\mathrm{one}\right)},$$

where χ = U ₂ Δf _P2 / U ₁ Δf _P1 ,

and quality factor Q of the resonance structure as

$$Q=\frac{f_p}{\Delta f_{Pi}}\sqrt{{\left(U_P/U_i\right)}^2-\mathrm{one}},$$

where i is 1 or 2.

The technical problem to be solved is a device for measuring the characteristics of resonant structures, comprising a frequency-tunable generator, a switch, a detector connected to a controller for measuring and measuring the characteristics of resonant structures, as well as series-connected the first transmission line, the resonant structure and the second transmission line, the first output of the switch connected to the input of the first transmission line, its second input to the output of the second transmission line, and the second output to the input of the detector, while tunable by h In this case, the generator, the switch and the controller for controlling and measuring the characteristics of the resonant structures have control inputs / outputs integrated in the control bus, it is achieved by the fact that a single-frequency to two-frequency oscillation converter is additionally introduced into it, and the detector is designed as an envelope detector, while the single-frequency oscillation converter dual-frequency has control inputs / outputs connected to the control bus, its input is connected to the output of a frequency-tunable generator, and the output to the first input mutator.

Figure 1 shows the structural diagram of the device.

Figure 2 shows the dependence of the modulation coefficient of the beat envelope of the sounding vibration signals received at the output of the single-frequency to two-frequency vibration converter, transmitted through or reflected from the resonant structure and detected at the detector output, from the generalized detuning of the passband of the resonant structure.

A device for measuring the characteristics of resonant structures (Fig. 1) comprises a frequency-tunable generator 1, a switch 2, a detector 3 connected to a controller 4 for controlling and measuring the characteristics of the resonant structures, as well as a first transmission line 5, a resonant structure 6 and a second line connected in series transmission 7, and the first output of the switch 2 is connected to the input of the first transmission line 5, its second input to the output of the second transmission line 7, and the second output to the input of the detector 3. Frequency-tunable generator 1, comm the tator 2 and the controller 4 for controlling and measuring the characteristics of the resonant structures have control inputs / outputs integrated in the control bus 8. The device is additionally equipped with a single-frequency to dual-frequency converter 9, the detector 3 is designed as an envelope detector, and the single-frequency to two-frequency converter 9 control inputs / outputs connected to control bus 8, its input is connected to the output of frequency-tunable generator 1, and the output to the first input of switch 2.

1, the first 5 and second 7 transmission lines, made on the basis of a coaxial cable, are conventionally shown in dashed lines. The connections between the frequency-tunable generator 1, the single-frequency to dual-frequency converter 9, the switch 2 and the detector 3 are also shown by dashed lines, since they are related to microwave blocks. The type of compounds used (strip, coaxial, waveguide, etc.) is not conventionally shown, since they can be performed in any design, including integral, with the integral combination of all units of the device for measuring the characteristics of resonant structures. All units have a power supply system, which is not shown in the structural diagram of the device.

Figure 2 shows the dependence of the modulation coefficient of the beat envelope of the sounding oscillation signals received at the output of the single-frequency to dual-frequency oscillation transducer 9, passed through or reflected from the resonant structure 6 and registered at the output of the detector 3, on the generalized detuning of the passband of the resonant structure 6.

The sounding oscillation in the proposed device, in contrast to the sounding oscillation in existing devices and the prototype is dual-frequency. The dependence depicted in FIG. 2 is presented for the case of sensing the resonant structure 6 with a two-frequency oscillation with a difference frequency less than or equal to the width of its passband. A characteristic point is the point of zero generalized detuning, which corresponds to the equality of the average frequency of the probe vibration to the resonant frequency of the resonance structure 6. In this case, the amplitudes of the components of the probe vibration are equal, and the modulation coefficient of the envelope of the beat signal of the components of the probe vibration at the difference frequency at the output of detector 3 will be unity. This fact is used to decide on the determination of the resonant frequency.

Consider the implementation of the method for measuring the characteristics of resonant structures and the operation of the device for its implementation.

The controller 4 for controlling and measuring the characteristics of the resonant structures contains a program that implements an algorithm for controlling the operation of individual units of the device and an algorithm for measuring the characteristics of resonant structures, which are presented in Appendixes 1 and 2 to this application. To measure the characteristics of resonant structures using a frequency-tunable generator 1, an initial single-frequency oscillation is generated, which is converted into a sounding oscillation in a single-frequency oscillation transducer 9 in a two-frequency oscillation.

To this end, from the controller 4 for controlling and measuring the characteristics of the resonant structures through the control bus 8, a command is sent to control the parameters of the generation of the frequency-tunable generator 1 and converting the single-frequency oscillation into a two-frequency oscillation in the converter 9. The algorithm for controlling the controller 4 for controlling and measuring the characteristics of the resonant structures by the operation of the individual units of the device via the control bus 8 is presented in Appendix 1.

In accordance with the command, the sounding oscillation in the transducer 9 of the single-frequency oscillations in the two-frequency form double-frequency, consisting of two single-frequency signals of equal amplitude, respectively, at frequencies f ₁₁ and f ₁₂ . For its formation in a frequency-tunable generator 1, an average frequency equal to f _C = (f ₁₁ + f ₁₂ ) / 2 is generated. The average frequency enters the transducer 9 of a single-frequency oscillation into a two-frequency one, in which, according to the received command, the initial difference frequency between the generated components of the two-frequency probing oscillation Δf _P1 = f ₁₁ -f _{12 is set} , which is usually less than or equal to the bandwidth of the resonant structure 6, while the middle frequency itself is suppressed.

Then the probe oscillation is transmitted to the resonant structure 6 through the switch 2 and the first transmission line 5. In the probe oscillation passing through the resonant structure 6, the amplitudes of the components of the probe oscillation change, they become unequal depending on the relative position of its average frequency and the resonant resonant frequency structures 6.

Next, a sounding oscillation is taken after the resonant structure 6 is exposed to the detector 3. In this case, two reception modes can be realized depending on the type of the resonant structure 6 adapted to operate on reflection or transmission. When working on reflection in accordance with the control algorithm on the control bus 8, switch 2 is switched on from the controller 4 for controlling and measuring the characteristics of the resonant structures into the "circulator" mode, so that the output two-frequency oscillation reflected from the resonant structure 6 through the first transmission line 5 and the first output of the switch 2 is fed to the second output of switch 2 and then to detector 3. When transmitting in accordance with the control algorithm on control bus 8, switch 2 is turned on from controller 4 of control and Nia characteristics of resonant structures in mode "magic tee", so that passed through the resonant structure of two-frequency oscillation output 6 through the second transmission line 5 and the second input of the switch 2 is supplied to the second output of the switch 2 and further to the detector 3.

At the output of detector 3, a signal is generated corresponding to the envelope of the beats of two components of the output two-frequency oscillation reflected from or transmitted through the resonant structure 6.

Then, in accordance with the control algorithm, a command is sent via the control bus 8 from the controller 4 for controlling and measuring the characteristics of the resonant structures to a frequency-tunable generator 1 for tuning the average frequency of the probing two-frequency oscillations with a given step in the measurement range corresponding to the frequency band of the resonant structure 6, and a converter 9 of a single-frequency oscillation into a double-frequency to keep the difference frequency Δf _P1 constant during tuning.

During tuning, in the controller 4 for controlling and measuring the characteristics of the resonant structures, a change in the average frequency of the probe oscillation f _C = (f ₁₁ + f ₁₂ ) / 2 is recorded and the modulation coefficient m of its envelope at the output of the detector 3 is measured, after which the value m = 1 ( 2) define the resonance frequency f _P of the resonance structure 6, as a value equal to the average frequency f _C in the given time and its corresponding measured amplitude of the envelope of oscillations of the probing U ₁ at the output of the resonant structure 6. measurement algorithm character tic resonant structures in the controller 4 and the measurement is presented in Appendix 2.

Figure 2 shows the dependence of the modulation coefficient of the beat envelope of the sounding oscillation signals received at the output of the single-frequency to dual-frequency oscillation transducer 9, passed through or reflected from the resonant structure 6 and registered at the output of the detector 3, on the generalized detuning of the passband of the resonant structure 6 for the case of supply on it a two-frequency sounding oscillation with a difference frequency less than or equal to the width of the specified passband.

A characteristic point is the point of zero generalized detuning, which corresponds to the equality of the average frequency of the probe vibration to the resonant frequency of the resonance structure 6. In this case, the amplitudes of the components of the probe vibration become again equal, and the modulation coefficient of the envelope of the beat signal of the probe vibration components at the differential frequency at the output of detector 3 will be equal to unit. This fact is used to decide on the determination of the resonant frequency f _{P of the} resonant structure 6.

At the moment, in accordance with the control algorithm, a command is sent via the control bus 8 from the controller 4 for controlling and measuring the characteristics of the resonant structures to a frequency-tunable generator 1 to stop the change in the average frequency f _{C of the} probe oscillation, and to a converter 9 of a single-frequency oscillation in a two-frequency oscillation to change the initial the difference frequency Δf _P1 by a certain amount of 2Δf, so that the frequencies of the components of the probe oscillations become equal to f ₂₁ = f ₁₁ -Δf and f ₂₂ = f ₁₂ + Δf, respectively, and the second value The difference frequency Δf _P2 = Δf _P1 + 2Δf does not exceed the passband of the resonance structure. After executing the command in accordance with the measurement algorithm in the control controller 4 and measuring the characteristics of the resonant structures, the amplitude of the envelope of the beat signal of the components of the probe oscillation U _{2 is} recorded at the output of the detector 3.

Further, in accordance with the measurement algorithm in the controller 4 of the control and measurement of the characteristics of the resonance structures, the resonance amplitude U _{P of the} resonance structure 6 is calculated by the expression

$$U_P=\sqrt{\left({\chi }^2{U}_{\mathrm{one}}^2-{\mathrm{<figure-callout\; id="2"\; label="U"\; filenames="00000009.png"\; state="\{\{state\}\}">U</figure-callout>}}_2^2\right)/\left({\chi }^2-\mathrm{one}\right)},$$

where χ = U ₂ Δf _P2 / U ₁ Δf _P1 ,

quality factor Q of the resonance structure 6 in the expression

$$Q=\frac{f_p}{\Delta f_{Pi}}\sqrt{{\left(U_p/U_i\right)}^2-\mathrm{one}},$$

where i = 1, 2.

Thus, by measuring the output of the detector 3:

- the modulation coefficient m of the envelope of the beat signal of the components of the probe oscillation reflected from or passed through the resonant structure 6, determine the resonant frequency f _P with the equality m = 1;

- the amplitudes U ₁ and U _{2 of the} envelope of the beat signal of the components of the probe vibration reflected from or passed through the resonant structure 6, determine the resonance amplitude U _P at different difference frequencies Δf _P1 and Δf _P2 and tune to the resonant frequency f _C = f _P ,

then, the Q factor of the resonance structure 6 is calculated from the obtained values.

A device for implementing the method can be implemented using various types of resonant structures 6, the specific form of which is determined depending on the tasks to be solved and, in turn, the type of measurements taken: reflection or transmission. It can be strip, waveguide, planar and volume resonators, etc.

A device for implementing the method for measuring the characteristics of resonant structures can be implemented on the following elements, designed to operate in the microwave range 1-5 GHz:

- frequency tunable generator 1 - AD9914 generator from Analog Devices;

- Switch 2 - controlled circulators, dual T-bridges or combined devices of Microwave Devices or FSUE Istok;

- detector 3 - envelope detector ADL5511 from Analog Devices;

- controller 4 - microprocessor controller based on chips from Atmel, Microchip, etc .;

- the first and second transmission lines 5, 7 - coaxial cables of the type RK, strip lines or segments of waveguides in accordance with the band of the resonant structure;

- control bus 8 - buses that implement the transmission of control signals and data via Modbus, RS and other protocols;

- Converter 9 single-frequency oscillations in two-frequency - N-channel frequency synthesizer ADF4156 company Analog Devices.

When implementing a device for implementing a method for measuring the characteristics of resonant structures, all of these blocks of generation, reception and processing of signals can be performed on a single chip in an integral design.

Compared with existing methods (including the prototype) for measuring the characteristics of resonant strip and devices for their implementation, linear or volume sensors, which are characterized by changes in the resonant frequency, amplitude and quality factor depending on changes in the electrophysical parameters of the materials filling the sensor during processing processes, for example, curing polymers, the proposed method and device with dual-frequency sounding of the resonator sensor and measuring the mode coefficient The variation and amplitude of the envelope of the beats of the probe pair of signals after reflection from or passing through the resonator sensor with further calculation of the resonance characteristics does not require:

firstly, the use of broadband reception, and allows you to process the signal at the beat frequency of the components of the two-frequency signal equal to the difference frequency between them, which significantly reduces the passband of the receiving part of the device (from units of GHz to units of MHz) and, accordingly, increases the signal-to-noise ratio of measurements;

secondly, the use of a peak detector with direct detection, which is characterized by the strong dependence of the signal-to-noise ratio on the intensity of noise and other fluctuations, especially in the low-frequency region, and uses an envelope detector whose passband is in the region of the minimum noise of the receiving part of the device, which accordingly, it also increases the signal-to-noise ratio of the measurements and avoids the effect on the measurement accuracy of intense low-frequency fluctuations and interference.

In direct detection, the intrinsic noise of the radiation detector prevails over the external and determines the threshold power of the received signal. The signal-to-noise gain can be calculated using the following expression

$$G={\displaystyle \underset{0}{\overset{\Delta fPP}{\int }}S\left(f\right)df}/\begin{array}{c}\Delta f_{P2}-\Delta f_{PP}\\ {\displaystyle \int }\\ \mathrm{<figure-callout\; id="2"\; label="\Delta \; f\; P"\; filenames="00000009.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{f}_P{2}_{}+\Delta f_{PP}\end{array}S\left(f\right)df,$$

where S (f) is the spectral density of the noise of the detector. In this case, the gain will be determined mainly by the different nature and level of noise in different frequency ranges, despite a slight increase in the required bandwidth. For direct detection of the range {0, Δf _pp } in the peak detector, these are current noises with a 1 / f distribution and other powerful noises and fluctuations of a low-frequency nature, for the range {ΔfP ₂ -Δf _pp , Δf _P2 + Δf _pp } of the envelope detector is the shot noise of low intensity, where Δf _pp is the passband of the detector, which is necessary for recording the amplitude of the probe oscillation after its interaction with the resonant structure. For measurements in the microwave range, the gain can be 1-2 orders of magnitude.

Tests of a method for measuring the characteristics of resonant structures and an experimental device for its implementation were carried out in the laboratory of the REC “Research Center for Applied Electrodynamics” KNITU-KAI A.N. Tupolev on resonance sensors made on Bragg cable coaxial gratings made in the REC “Fiber-optic technologies” KNITU-KAI named after A.N. Tupolev, calibrated on R&S FSH8 vector network analyzers, calibration verified on R&S ZWA50 vector network analyzers in the laboratory of the Volga State University of Telecommunications and Informatics (Samara), and showed that the use of two-frequency sounding of a resonant sensor with measurement of the characteristics of resonant structures along the envelope the beats of the component of the two-frequency output signal made it possible to achieve a signal-to-noise ratio of measurements up to 45 dB and a relative measurement error of 0.01%. In this case, the measurement error was determined mainly by the error of the ADC controller when measuring the envelope amplitude.

All this allows us to talk about achieving a solution to the technical problem - increasing the sensitivity and accuracy of devices for measuring the characteristics of resonant structures.

Claims (2)

1. The method of measuring the characteristics of resonant structures is that they generate a sounding oscillation, supply it to the input and receive from the output of the resonant structure, reconfigure the frequency of the sounding vibration in the measurement range corresponding to the frequency band of the resonant structure, register changes in its parameters, which determine the resonance frequency f _p, U _p the amplitude and quality factor Q of the resonant structure, characterized in that the probe oscillation at the resonant structure form the entrance to a two-frequency dd mja components of equal amplitude respectively at the frequencies f ₁₁ and f ₁₂ with a center frequency f _C = (f ₁₁ + f ₁₂₎ / 2 and an initial difference frequency Δf _P1 = f ₁₁ -f ₁₂ of less than or equal to the bandwidth of the resonant structure, an average rearrange the frequency f _{C of the} probe oscillation, and during the tuning, the initial difference frequency Δf _{P1 is} left unchanged, the change in the average frequency of the probe oscillation f _C = (f ₁₁ + f ₁₂ ) / 2 is recorded and the modulation coefficient m of the envelope of the beat signal between the probe oscillation components Exit resonant structure for achieving the modulation value m = 1 was measured resonance frequency f _P of the resonance structure factor as equal to the value of the mean frequency f _C in the given time and measured its corresponding amplitude envelope of the beat signal between the components of the probe oscillations U ₁ at the output of the resonant structure, more without changing an average frequency f _C probe oscillation, change the initial difference frequency Δf _P1 by a predetermined value 2Δf, so that the values of the frequency components of the probe oscillations become tsya are respectively f ₂₁ = f ₁₁ -Δf and f ₂₂ = f ₁₂ + Δf, and the value of the difference frequency Δf _P2 = Δf _P1 + 2Δf does not exceed the bandwidth of the resonant structure, and then measure the amplitude of the envelope of the beat signal components between the probe oscillations U ₂ at the output of the resonance structure, calculate the resonance amplitude U _{P of the} resonance structure by the expression

,
where χ = U ₂ Δf _P2 / U ₁ Δf _P1 , and the quality factor Q of the resonance structure according to the expression

,
where i is 1 or 2,
f _p is the resonant frequency,
U _p is the resonant amplitude,
U _i - the amplitude of the envelope of the beat signal between the components of the probe oscillation,
Δf _Pi is the difference frequency. 2. A device for measuring the characteristics of resonant structures, comprising a frequency-tunable generator, a switch, a detector connected to a controller for controlling and measuring the characteristics of resonant structures, as well as a series-connected first transmission line, a resonant structure and a second transmission line, wherein the first output of the switch is connected to the input of the first transmission line, its second input to the output of the second transmission line, and the second output to the input of the detector, while the frequency-tunable generator, switch and the controller for controlling and measuring the characteristics of the resonant structures have control inputs / outputs integrated into the control bus, characterized in that a single-frequency to two-frequency vibration converter is additionally inserted into it, and the detector is designed as an envelope detector, and the single-frequency to two-frequency vibration converter has inputs / control outputs connected to the control bus, its input is connected to the output of a frequency-tunable generator, and the output is to the first input of the switch.

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