VOLTAGE-CONTROLLED OSCILLATOR FOR PRODUCING MULTIPLE FREQUENCY BANDS

摘要

An object of the present invention is to provide a multi-band voltage-controlled oscillator in which switching means can certainly be turned on and off. For achieving the above object, the oscillator of the present invention includes a negative source generator (67) coupled to an output of a buffer transistor (22) from which an oscillation frequency of an oscillating transistor (21) is released, switching means (40) for selectively switching between an output of the negative source generator (67) and a positive power source, and mode switching means (66) receiving an output frequency switching signal from the outside. An output of the switching means (40) controls an opening and short-circuiting operation of first switching means (38a) to selectively release oscillation outputs in a low frequency band and high frequency band from an output port (49).