| 摘要 |
PROBLEM TO BE SOLVED: To provide an RF communication unit which can decrease the number of external control ports to attain the reduction of its size and cost. SOLUTION: A (Tx+B1) signal is activated, a VCO amplifier 12 is turned on, the channel selection data are inputted to a PLL 10, the oscillation frequency of the amplifier 12 is locked at its desired level, and the LD(lock detection) signal sent from the PLL 10 is activated. Under such conditions, the output of an AND circuit 11 becomes active and a switch 14 of a power amplifier 15 is turned on. Thus, the amplifier 15 operates to perform an output operation. |
