Patent ID: 8466721

Claim:
An injection locked frequency divider comprising: a ring oscillator that cascade-connects amplifier circuits each including an N-channel metal oxide semiconductor transistor and a P-channel metal oxide semiconductor transistor in (2n+1) (n is any natural number) stages in a ring; an electric current source that is connected to the ring oscillator and includes an N-channel metal oxide semiconductor transistor that drives the ring oscillator; and a differential signal injection circuit that outputs an injection signal to the ring oscillator and outputs a reverse phase signal of the injection signal as a differential signal to the electric current source, wherein: the drain of the N-channel metal oxide semiconductor transistor of the electric current source is connected to the source of the N-channel metal oxide semiconductor transistor of the ring oscillator; and the differential signal injection circuit outputs the injection signal to the gate of the P-channel metal oxide semiconductor transistor of the ring oscillator and outputs the differential signal to the gate of the N-channel metal oxide semiconductor transistor of the electric current source.