| 摘要 |
PURPOSE:To cut a demand, to reduce a calorific value, to improve profitability, and to miniaturize a structure, by controlling a power source voltage synchronizing with the presence/absence of a burst-shaped RF signal, and impressing a bias voltage on an amplifier only when the signal exists. CONSTITUTION:A burst signal sending control circuit 21 controls a protection circuit 3 so that the power source voltage is impressed on a high output transistor amplifier 1 only when the RF signal exists. In other words, a transistor 22 is turned on or off by the control signal from the burst sending control circuit 21. Therefore, a transistor 9 is turned on or off. Consequently, since a transistor 8 goes to an on-state only when the RF signal exists, a current is permitted to flow on a field effect transistor 7, thereby accomplishing a function as the high output transistor amplifier 1.
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