Patent ID: 6566969
Filing Date: 2003-05-20
Classification: H03B

Abstract:
A high frequency dual band output oscillator comprising:an oscillation transistor (6a) providing a first output oscillation circuit (1a) operating in an oscillation manner at a first frequency band, an oscillation transistor (6b) providing a second output oscillation circuit (1b) operating in an oscillation manner at a second frequency band, one broad band buffer amplifier circuit (4) into which an oscillation output of said first output oscillation circuit (1a) enters through a stage-to-stage coupling element (22) and an oscillation output of said second output oscillation circuit (1b) enters through a frequency selective filters (3a, 3b) and said stage-to-stage coupling element (22), said frequency selective filter (3a, 3b) comprising a frequency selective filter inductance (14) and a frequency selective filter capacitor (15), and a single switch terminal (2) controlling an operation or a non-operation of one of said first and second output oscillation circuits (1a, 1b), wherein an oscillation signal from said first or second output oscillation circuit is selectively outputted when a base voltage of said oscillation transistors (6a, 6b) is respectively controlled by an on-and-off of a control voltage that is externally applied to said switch terminal (2) and an operation and a non-operation of said oscillation transistors (6a, 6b) are exchanged.