PURPOSE: To facilitate the setting of circuit constitution and its constant by using one single gate FET and adopting circuit constitution comprising a microstrip line so as to apply even number frequency division of a signal in a microwave band, outputting the frequency division signal and extracting a signal of an integral number of multiple.

CONSTITUTION: A single gate FET of common source is used as an active element in nonlinear operation. A band pass filter 10 comprising an open end resonator having a length corresponding to one wavelength of an input signal frequency is arranged between a gate and an input terminal 8. Moreover, a band pass filter comprising a resonator whose one terminal connects to ground for a wavelength equipment to 1/4 wavelength of a 1/4 frequency division output frequency is arranged between the drain and an output terminal and between the gate and the drain respectively. Since oscillation equivalent to 1/4 frequency division frequency is caused by a FET 13 and a feedback loop and when a signal with the same wavelength as the length of the resonator of the band pass filter is inputted from the input terminal 8, the said frequency is divided by 1/4 and the result is outputted from an output terminal 9 via an output band pass filter 12.