Transistor power oscillator, electronically tunable from 250 to 500 MHz

Three basic types of the so-called emitter-coupled oscillator may be distinguished. If the power output is taken from the emitter branch, the dependence of power on frequency is small up to frequencies of approximately fα/2. An experimental power oscillator electronically tunable from 230 to 530 MHz delivers an average output power of 3.5 watts. The broad tuning range despite the high power level is due to the fact that with a series connection of inductance and varactor it is not necessary to restrict the varactor bias to the reverse region--the varactor may even be forward-biased up to slightly beyond the diode knee voltage.