| 摘要 |
PROBLEM TO BE SOLVED: To secure isolation between transmission and reception, to prevent the deterioration of the noise figure and to reduce current consumption by turning on the power on the reception side only at the reception timing of a mobile terminal where transmission timing, reception timing and idling timing are set. SOLUTION: Transmission power timing 1 becomes at a high level only for a transmission period T and power is supplied to a transmission part. Reception power timing 2 becomes at the high level only for a reception period R and power is supplied to a reception part. Since the power of the reception part is turned off during transmission, abnormal oscillation and unnecessary radio wave radiation do not occur even if the signal of a transmission frequency band leaks into the reception side through a duplexer. For preventing the load fluctuation of a synthesizer with the turn-on of the power in the reception part from adversely affecting a transmission signal, the timing to the turn-on of the power in the reception part is delayed slightly from the timing of the turn-off of the power in the transmission part or the reception part except a low noise amplifier is operated. |
