METHOD FOR MEASUREMENT OF CHARACTERISTICS OF RESONANT STRUCTURES AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2015 - IPC G01R27/00 

FIELD: measurement equipment.

SUBSTANCE: method for measurement of characteristics of resonant structures consists in the fact that a single-frequency sounding oscillation is generated, converted to a multi-frequency one, supplied to the input and received from the output of the resonant structure; frequency of the sounding oscillation is retuned in the measurement range corresponding to the frequency bandwidth of the resonant structure; changes in its parameters, as per which resonant frequency f_r, amplitude U_r and quality factor Q of the resonant structure is determined, are recorded. A peculiar feature of this method is that a sounding oscillation at the input of the resonant structure is shaped as two double-frequency oscillations with two pairs of components of equal or in-pair equal amplitude on frequencies f₁₁, f₁₂ and f₂₁, f₂₂ respectively with similar average frequency f_A=(f₁₁+f₁₂)/2=(f₂₁+f₂₂)/2 and different difference frequencies Δf_D1=f₁₁-f₁₂ and Δf_D2=f₂₁-f₂₂, which are lower or one of which is equal to a band pass of the resonant structure, average frequency f_A is retuned. During re-tuning, difference frequencies Δf_D1 and Δf_D2 remain unchanged, variation in average frequency of sounding oscillation f_C is recorded, and at the same time, a measurement is made for modulation coefficient m₁ and m₂ of envelopes of beat signal between components of the first and the second double-frequency oscillations at the output of the resonant structure. When modulation coefficient achieves m₁=m₂=1, resonant frequency f_r is measured as equal to the value of average frequency f_A at this point of time and its corresponding amplitudes of envelopes of beat signal are measured between components of the first and the second double-frequency oscillations U₁ and U₂ at the output of the resonant structure; then, resonant amplitude U_R of the resonant structure is calculated by the following expression: $$U_p=\sqrt{\left({\chi }^2{U}_1^2-U_2^2\right)/\left({\chi }^2-1\right)},$$ where χ=U₂Δf_R2/U₁Δf_R1, and quality factor Q of the resonant structure - $$Q=\frac{f_p}{\Delta f_{Pi}}\sqrt{{\left(U_p/U_i\right)}^2-1},$$ where i is equal to 1 or 2. To the measurement device of characteristics of resonant structures, which includes the following elements that are in-series connected: a generator that is retunable as to frequency, a converter of a single-frequency oscillation to a multi-frequency one, a commutator and a detector, as well as a controller for control and measurement of characteristics of resonant structures, the first transmission line, a resonant structure and the second transmission line, which are in-series connected to the commutator and where the second output of the commutator is connected to the input of the first transmission line, and the second input of the commutator is connected to the output of the second transmission line, there additionally introduced are retunable selective filters of the first and the second difference frequencies respectively, which are connected with their inputs parallel to the detector output and with the outputs to the first and the second inputs of the controller for control and measurement of characteristics of resonant structures respectively, and the generator retunable as to frequency, the converter of single-frequency oscillation to the multi-frequency one, the commutator, the controller for control and measurement of characteristics of resonant structures and retunable selective filters of the first and the second difference frequencies respectively have control inputs/outputs, which are combined into a control bus.

EFFECT: improving sensitivity and accuracy of measurements.

2 cl, 3 dwg, 2 app

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