| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce power consumption at the time of the reception standby of the mobile transmitter-receiver of a TDMA system for which a reception band is allocated lower than a transmission band. SOLUTION: Reactance added to the resonance circuit 21 of the frequency band changeover part 25 of the VCO of the output circuit of a frequency synthesizer for switching and supplying local oscillation signals to a transmission/ reception mixer is constituted of the serial circuit of a first capacitor C2 and a coil L1 and a second capacitor C3 parallelly connected to the coil L1 and turned ON/OFF by transmission/reception band changeover signals (b). When the C3 is OFF, a reception frequency band is attained and the current consumption of a switch circuit 23 becomes zero.</p> |
