PURPOSE: To obtain a system that can be digitalized and does not require adjusting work by detecting digitally phase shifting point by a phase shifting point detecting circuit and applying phase locking so that the output phase of the phase shifting point detection output and a digital phase synchronizing loop circuit maintains fixed phase relation at all times.
CONSTITUTION: A phase modulating signal A is made to a shaping wave output by an amplifying shaping circuit 1 and inputted to a differentiation circuit. On the other hand, a lock pulse 11 of the first phase is inputted from the first two- phase clock generating circuit 3 to the differentiation circuit 2. Differentiation output I is inputted to the first base synchronizing loop circuit 4, and the result is compared in phase with the output K of octal counter 43 obtained by dividing the clock pulse 11 by 8 in a phase comparing section 41. If the differentiation output I is advanced, the output of the octal counter 43 is advanced by a clock controlling section 42 by inserting 1 clock of the second clock pulse 12. Conversely, if the differentiation output I is delayed, phase synchronizing is made by delaying advancing force of the octal counter 43 removing 1 clock of the first phase clock pulse 11.
HIRAI MASATO
SHIMANUKI TAKESHI
