| 摘要 |
PROBLEM TO BE SOLVED: To make lower the power consumption of a high-frequency transmission and reception device for radio communication in standby mode. SOLUTION: A high-frequency signal received by a receiving antenna 1A is inputted to a down converter 5 and converted into an intermediate frequency, processed through a band-pass filter 6, an amplifier 7, a detector 8, and a comparator 9, and sent as demodulated receive data to a CPU, etc. Data for transmission is modulated by a modulator 10 and sent from a transmitting antenna 1B through an amplifier 11. In standby mode, the power supply to a transmission and reception device main body is cut off, but when a detecting circuit which consists of a reception detection antenna 1C, a detector 12, an amplifier 13, and a comparator 14 and normally operates detects a radio wave and extracts receive data, a control circuit 15 drives an LED 16 and a buzzer 17 to indicate that a reception mode should be entered and power is turned ON the main body. |
