For the need of measurements focused in condensed matter physics and especially Bernoulli effect in superconductors we have developed an active resonator with dual operational amplifiers. A tunable high-Q resonator is performed in the schematics of the the General Impedance Converter (GIC). In the framework of frequency dependent open-loop gain of operational amplifiers, a general formula of the frequency dependence of the impedance of GIC is derived. The explicit formulas for the resonance frequency and Q-factor include as immanent parameter the crossover frequency of the operational amplifier. Voltage measurements of GIC with a lock-in amplifier perfectly agree with the derived formulas. A table reveals that electrometer operational amplifiers are the best choice to build the described resonator.
@article{arxiv.2105.11536,
title = {Tunable High-Q Resonator by General Impedance Converter},
author = {T. Mifune and T. M. Mishonov and N. S. Serafimov and I. M. Dimitrova and R. Popeski-Dimovski and L. Velkoska and E. G. Petkov and A. M. Varonov and A. Barone},
journal= {arXiv preprint arXiv:2105.11536},
year = {2021}
}
Comments
a new formulae for the Q-factor expressed by resonance frequency, dominant frequency and cross-over frequency, a general guide with a table for selection of appropriate operational amplifiers, 9 new (30 total) references, Fig. 6 in appendix B corrected