FM DEMODULATION CIRCUIT

• Main Authors: TANAKA TAKAKO, NIHONSUGI TAKASHI, SAKAMOTO HIDEO, IKEDA MITSUHARU
• Format: Patent
• Language: English
• Published: 02.11.2006
• Subjects: BASIC ELECTRONIC CIRCUITRY; DEMODULATION OR TRANSFERENCE OF MODULATION FROM ONE CARRIER TOANOTHER; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PROBLEM TO BE SOLVED: To reduce temperature changes due to the difference of delay times between two delayed FM-modulated signals. SOLUTION: An FM demodulation circuit 4 branches an FM-modulated signal input from a child device into two paths. Two delay circuits 40 and 41 amplify the FM-modulated signals through OR circuits 400 and 410, and delay the FM-modulated signals using delay elements 403 and 413 that have different parameters to output the two delayed FM-modulated signals to a phase detection circuit 42. The phase detection circuit 42 conducts phase-detects, using the difference of phases based on the difference of delay times between the two delayed FM-modulated signals to output a detected signal to an LPF circuit 43. The LPF circuit 43 removes high-frequency components from the detected signal to output it as an FM-demodulated signal to a display circuit. COPYRIGHT: (C)2007,JPO&INPIT