PURPOSE: To always obtain a desired phase shift degree despite a phase shift circuit incorporated into an IC by producing the pulse signal having a prescribed phase difference to the oscillation signal from a D-FF circuit.

CONSTITUTION: The transmission signal led to a terminal P1 is squared by a squaring circuit 21, undergoes the waveform shaping to be changed to a pulse signal S3 of 50% duty through a waveform shaping circuit 22 and supplied to a D-FF circuit 23 in the form of a clock pulse. While the oscillation signal led to the terminal P1 undergoes the waveform shaping to be changed to a pulse signal S4 of 50% duty through a waveform shaping circuit 24 and is supplied to the circuit 23 in the form of a D input. In such a constitution, the fall phase of the signal S3 has a 45 shift compared with the fall phase of the signal S4. Here the circuit 23 is set so that the signal S4 is read in the fall timing of the signal S3. Therefore a Q output signal S5 has a phase delayed by 45 compared with the signal S4. As a result, the variance of phase shift degree is reduced, and no problem is produced although an oscillated signal is converted into an IC.