To minimize the phase fluctuation of a timing signal outputted from the phase locked loop oscillation circuit.

A wavelet filter 40A is used to apply wavelet transformation to a phase fluctuation of an input signal 10 to a phase locked loop oscillator 20 and its output signal 30, the phase fluctuation is separated into a periodic fluctuation component and an aperiodic fluctuation component by wavelet conversion, and a gain of the phase locked loop oscillator 20 is optimized based on the periodic fluctuation component and a power supply filter of the phase locked loop oscillator 20 is optimized based on the aperiodic fluctuation component.