A dual band oscillator circuit according to the present invention comprises an oscillator circuit portion (1a) that oscillates at a first frequency, an oscillator circuit portion (1b) that oscillates at a second frequency, a buffer amplifier circuit portion (2c) to which an output of the first oscillator circuit portion (1a) is input through a first stage-to-stage coupling element (16a) and an output of the second oscillator circuit portion (1b) is input through a second stage-to-stage coupling element (16b). Operation is switched between the first and second oscillator circuits (1a, 1b) by an externally applied control voltage signal (at 24a,24b). <IMAGE>
