An electronic oscillator of the Colpitts type with an amplifying element and a tank circuit. The tank circuit includes a parallel tuned resonant circuit, a series tuned resonant circuit and a switching circuit that selectively connects one of the resonant circuits to the tank circuit. The oscillator operates at a first frequency in the parallel tuned mode and a second frequency that is substantially twice the first frequency in the series tuned mode.
First And Second Oscillator Circuits Selectively Coupled Through Passive Output Circuit To A Load
Matthew D. Pope - Aurora CO Jeffrey T. Gudewicz - Denver CO
Assignee:
Vari-L Company, Inc. - Denver CO
International Classification:
H03B 512 H03B 518
US Classification:
331 49
Abstract:
An oscillator having two oscillation circuits with widely different frequencies with a common passive switched output circuit. Each oscillator circuit includes a transmission line inductive impedance between the oscillator output and ground. The inductive impedances are selected to be open at the operating frequency of the associated oscillator circuit and a short or a low impedance at the frequency of the other oscillator circuit. Each inductive impedance forms a portion of an impedance matching pad for the other oscillator circuit.
An oscillator having a tank circuit, an amplifier circuit and a switching circuit. The switching circuit switches the oscillator between a normal power consumption mode and a lower power consumption mode. The amplifier circuit includes an emitter biased transistor. The switching circuit switches between power consumption modes by switching between two selected voltages at the base of the transistor. When in the lower power consumption mode, the oscillator has sufficient current to sustain oscillation but insufficient current to meet the phase noise requirements for good fidelity and high data rates. When in the normal power consumption mode, the oscillator has sufficient current to meet the phase noise requirements for good.