Tunable high-Q resonator by general impedance converter

Abstract

A tunable high-Q resonator is performed in the schematics of 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 an immanent parameter the crossover frequency of the operational amplifier. Voltage measurements of GIC with a lock-in amplifier perfectly agree with the derived formulas.

Set-up for observation thermal voltage noise and determination of absolute temperature and Boltzmann constant

“…The development of some set-ups required additional study of circuits with operational amplifiers (OpAmps). This led to introduction of the master equation of OpAms applied to the stability of circuits with Negative Impedance Converter (NIC) [42], Generalized Impedance Converter [59] and study of Probability Distribution Function [29] of the crossover frequency of OpAmps. Continuing this stile, the scientific description of the set-up of the present Olympiad (EPO9) is given at university education level [60].…”