Tunable high Q solid state inductive elements

An analysis will be presented which predicts a group of transistor-like devices which are capable of producing high Q, tunable inductance. The complex nature of α is utilized to produce such inductive behavior. An experimental verification was made by the fabrication of a low frequency, germanium transistor. Inductances of millihenries at several hundred KC to one Henry at 100 cps have been produced. The device inductance is adjustable from very low values to the maximum value by varying the base resistance and the collector capacitance. The internal and external damping resistances are canceled by the negative resistance produced with avalanche operation to give very high values of Q at moderate bias conditions. Improved temperature stability has been achieved over other approaches to solid state inductance. This high Q miniaturized inductance should be a very useful complement in the various approaches to solid state microelectronics.