PHASE SYNCHRONIZING CIRCUIT HAVING LOOP GAIN DIFFERENTIATED IN ACCORDANCE WITH PHASE DIFFERENCE OF INPUT SIGNAL

• Main Author: KURAMOCHI YUZO
• Format: Patent
• Language: English
• Published: 20.04.2001
• Edition: 7
• Subjects: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION, OR STABILISATIONOF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES; BASIC ELECTRONIC CIRCUITRY; ELECTRICITY

PROBLEM TO BE SOLVED: To reduce the power level of an electromagnetic wave radiated from an output signal of a phase synchronizing circuit. SOLUTION: The phase relation of signals applied to a phase frequency comparator 10 in the phase synchronizing circuit 1 is detected, an area existing near to an input signal 16 is set as a fixed operation area and an area separated from the signal 16 is set as a normal operation area. When an output signal from a VCO 13 exists in the normal operation area, the circuit 1 is allowed to execute normal operation, and when the output signal entered into the fixed operation area, the circuit 1 is controlled so as to hold the loop gain of the circuit 1 at a fixed level. In the constitution, the output signal from the VCO 13 is varied in a prescribed phase range and a sharp power spectrum included in the original output signal can be dispersedly reduced.