A device for directly measuring the amplitude ratio of weakly coupled resonators

Abstract

The invention discloses a device for directly measuring the amplitude ratio of a weakly coupled resonator, which is specifically composed of a weakly coupled resonator, two displacement signal processing loops, a digital phase-locked loop module, an amplitude closed-loop control module, and a digital-to-analog converter. Among them, the digital phase-locked loop module and the amplitude closed-loop control module are realized by FPGA programming. Weakly coupled resonators consist of two sets of identical resonators and coupling structures. Each displacement signal processing circuit includes a capacitor-voltage converter, a low-noise amplifier, a switching rectifier, a comparator, a low-pass filter, and an analog-to-digital converter. The digital phase-locked loop module includes a frequency and phase detector, a loop filter, a first PI controller, a digital voltage-controlled oscillator, and a comparator. The amplitude control module includes a low-pass filter, a second PI controller. The invention can realize the direct measurement of the amplitude ratio of the weak coupling resonator, without the need of subsequent division operation process, realizes the direct output of the circuit of the measurement signal, and reduces the complexity of the signal post-processing process.

Description

technical field [0001] The invention relates to a micromechanical weak coupling resonator system, in particular to a device for directly measuring the amplitude ratio of a weak coupling resonator. Background technique [0002] The weakly coupled resonator is a multi-degree-of-freedom resonant system that uses the amplitude ratio as the output evaluation index. Theory and experiments show that the relative mechanical sensitivity of the amplitude ratio modulation mechanism of weakly coupled resonators is 2 to 3 orders of magnitude higher than that of the frequency modulation mechanism of conventional single-degree-of-freedom resonators. In addition, since the structure of the weakly coupled resonant system is in the form of differential measurement, the system as a whole has a good suppression effect on external common-mode interference such as temperature fluctuations. Therefore, weakly coupled resonators have important military and civilian values ​​and broad application pr...

AI Technical Summary

Problems solved by technology

However, at present, most institutions measure the amplitude ratio of weakly coupled resonators through data post-processing, and it is still impossible to directly obtain the system output from the output of the measurement and control circuit, which limits the integrated application prospects of weakly coupled resonators.

Images