A Q-invariant active resonator

Abstract

A new RC-amplifier resonator has a pole Q which is invariant under passive element drift. The differential sensitivities S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</inf> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</sup> are all zero. The macroscopic sensitivities give ΔQ/Q=-12 ppm for ΔZ/Z=1 percent. Thermal coefficients of R and C can thus be chosen for constant center frequency in several ways without affecting the Q stability.