On the passive circuit adjustment of parametric amplifiers incorporating varactor diodes
T. Buckley · Journal of Scientific Instruments · 1964
A description is given of a time-saving method of adjusting the signal input circuit of a parametric amplifier to have any desired value of coupling ratio and to be resonant at a given frequency and diode bias voltage. The principle of the method is the sweeping of the bias voltage of the varactor diode at a low frequency and is a development of the method suggested by Kurokawa in an earlier paper.