| 摘要 |
PROBLEM TO BE SOLVED: To provide a portable telephone device which can reduce the device current. SOLUTION: A reception filter 2 prevents saturation of an amplifier in a receiver 3, caused by self transmission wave, to prevent deterioration of the reception sensitivity. The receiver 3 transmits received data and RSSI (Receive Signal Strength Indication) to a controller 4. The controller 4 processes the received data and RSSI and, when the RSSI level of the received wave at its own station is not larger than threshold, outputs a signal of a low level (LOW); and when the RSSI level is not lower than the threshold, outputs a high-level signal (HIGH). A transmitter 5 carries data received from the controller 4 on electromagnetic waves and amplifies it. A transmission filter 6 attenuates a reception band noise in the transmission waves, to prevent deterioration of a reception sensitivity. A change-over switch 7 is operated, so that the transmission wave from the transmitter 5 passes through the transmission filter 6, when the signal from the controller is at the LOW and the transmission wave from the transmitter 5 passes through the transmission filter 6, when the signal from the controller is at the HIGH. |
