Patent ID: 7492194

Claim:
An oscillator comprising a plurality of identical oscillation means formed to oscillate at an identical frequency and outputting a plurality of output signals with an identical output frequency and an identical phase; a plurality of identical dividers for dividing said output frequency from each oscillation means at an identical divide ratio; a plurality of identical phase frequency detectors, each phase frequency detector detecting the phase difference between two input signals, which are the output signal of the corresponding divider output and a common external reference signal, and outputting a control command signal for controlling the output frequency from each of the oscillation means; phase-synthesizing and outputting means for phase-synthesizing the plurality of output signals from the plurality of identical oscillation means and outputting a composite signal; lock detection means for detecting whether the two input signals are phase-locked to each other in each of said plurality of phase frequency detectors; activation means for activating said plurality of phase frequency detectors when it is determined by the lock detection means that the two input signals are not phase-locked to each other in all or at least a predetermined number of the plurality of phase frequency detectors; frequency dividers for at least some of said plurality of phase frequency detectors, the frequency dividers dividing the output signal and the reference signal to be obtained by each of said phase frequency detectors by predetermined division ratios; and division-ratio sequential setting means for setting, prior to the lock detection by said lock detection means, the division ratios of the frequency dividers corresponding to the output signal at a first preset frequency exceeding the upper limit frequency of an adjustable frequency range of the corresponding oscillation means and at a second preset frequency less than the lower limit frequency of the adjustable frequency range in a predetermined sequence and subsequently setting the division ratios of the frequency dividers corresponding to the output signal at the desired frequency.