| 摘要 |
PURPOSE:To adopt inexpensive components and to reduce adjusting time and man-hours by providing regions on an input signal plane to apply weighting to an output signal thereby relaxing considerably the adjustment of zero point offset quantity requiring extremely accuracy for an input signal of a phase comparator having been requested conventionally. CONSTITUTION:In giving an output 0 to a point being apt to be in phase comparison by mistake, that is, a point A because it exists in the 2nd region, since a loop filter has integration characteristics in general, a VCO control signal is unchanged. That is, the state existing before a signal corresponding to the point A is inputted is kept. In constituting the loop filter 3 by a digital signal processing circuit, an especially desirable operation is obtained because the complete integration characteristic is obtained. When the phase comparator input is expressed by a digital signal by means of the digital signal processing circuits for other parts of the system, the phase comparison characteristic is obtained easily as read data of a memory by allocating a couple of orthogonal detection signals by several bits each as an address of each memory (ROM). |
