Simple broad-band frequency-independent analog I/Q generator

Abstract

A wide frequency range, analog in-phase/quadrature generator was developed for use in synchronous detectors. With the parameters chosen for the realization reported in this Note, it can, in principle, operate from 60 Hz up to 400 kHz. Using good quality sine input, deviations from the 90° phase lag of the quadrature output are not larger than 0.2° in the frequency range between 60 Hz and 100 kHz.