A new oscillator circuit effective in frequency range 100 MHz to 1 GHz

We have proposed a new piezoelectric oscillator circuit suitable for use in frequency range 100 MHz to 1 GHz. The proposed oscillator is composed of a Colpitts oscillator and a two-stage common-emitter amplifier. The amplifier picks up the signal from the emitter of the oscillator transistor and feeds back the amplified signal to the base of the oscillator transistor via its base-collector capacitance. Simulation has shown that sufficiently large negative resistance can be obtained compared to the usual Colpitts oscillator. Other major performance factors have the values for practical use. Experiments with a 622 MHz voltage controlled SAW oscillator have agreed with the simulated results.