FREQUENCY COUNTING CIRCUIT

摘要

PROBLEM TO BE SOLVED: To provide a frequency counting circuit capable of more accurately measuring the frequency of modulated IF signals. SOLUTION: By counting the radio of 1/0 of data demodulated by a demodulation circuit (a) coincidentally with the counting of an IF pulse number, the error amount of the IF pulse number within fixed time is measured. This frequency counting circuit uses the measured error amount, corrects an IF count number by a correction circuit (e) and measures an IF frequency. An accurate IF frequency value is obtained without being affected by a count error by modulation.