A design basis for junction transistor oscillator circuits

A unified approach to the design of junction transistor oscillators is presented, based on a study of the dynamic admittance presented to the load at the oscillation frequency by a bilateral active four-pole network with passive feedback. The method, applicable to practical oscillator arrangements, leads to simple design expressions when appropriately simplified transistor parameters are used. The equivalent circuit used is suitable for transistors operating by drift and/or diffusion of minority carriers in the base region. Oscillation to the highest possible frequencies, or with the highest possible load, is achieved with optimized feedback networks; for practical transistor oscillators, these are found to be easily designable in terms of the transistor parameters h11 and ??. An expression for the maximum frequency of oscillation, fm, valid for transistors operating by drift and/or diffusion, leads to new methods for the measurement of certain high-frequency transistor parameters.