| 摘要 |
PROBLEM TO BE SOLVED: To reduce the change of a carrier frequency due to the impedance change of a power amplifier when switching from a blind time slot to an active time slot. SOLUTION: A transmitting circuit includes a voltage-controlled oscillator 2 which is PLL controlled in the blind time slot and released from the PLL control in the active time slot continued to the blind time slot to perform modulating, and a power amplifier 6 in which a power source is turned off in the blind time slot and the power source is energized in the active time slot to amplify the transmitting signal outputted from the voltage-controlled oscillator 2. The transmitting circuit further includes varactor diodes 8, 11 which shunts at least one of an input terminal and an output terminal of the power amplifier 6 in such a manner that a power source voltage is applied to the varactor diodes 8, 11 irrespective of on/off of the power of the power amplifier 6. COPYRIGHT: (C)2005,JPO&NCIPI
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