METHOD FOR MEASURING RESONANT FREQUENCY AND Q-FACTOR Russian patent published in 2022 - IPC G01R27/26 G01R23/02 

FIELD: measuring equipment.

SUBSTANCE: invention is intended for high-precision measurement of a resonant frequency and Q-factor of resonators that are part of various resonant sensors, for example, of humidity, concentration of solutions and level of various media. According to the claimed method, in the range of changes in a resonant frequency, a resonator is sequentially excited with a set of discrete frequencies, and an amplitude-frequency characteristic of the resonator is fixed, according to the maximum U_m of which, the resonant frequency is approximately determined, as well as the bandwidth of the resonator B_0.7 at a level of 0.707·U_m. Then, a frequency band B is selected, located symmetrically relatively to an approximate value of the resonant frequency, this band is divided into three equal disjoint sub-bands, and in each i-th sub-band, the resonator is excited at discrete frequencies ƒ_ik tunable with a step s_ƒ. At frequencies ƒ_ik, voltages at an output of the resonator U_ik are measured, these voltages are converted into inverse quadratic values , and these values are summed in each sub-band. After that, the resonant frequency ƒ_r and Q-factor Q are determined.

EFFECT: increase in the accuracy of measuring the resonant frequency.

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