| 摘要 |
PROBLEM TO BE SOLVED: To reduce power consumption by increasing amplification efficiency in a low output mode in a high frequency power amplifier. SOLUTION: In the radio communication device in which each field effect transistor of a multi-stage high frequency power module is controlled by an APC circuit based upon a power level instruction signal, when a high level signal based on the power level instruction signal is applied between a gate of a transistor of the final stage and the APC circuit, a gate voltage is linearly applied to the transistor of the final stage. Besides, when a low level signal based on the power level instruction signal is applied, the transistor of the final stage is integrated with a correction circuit in which a maximum gate voltage becomes lower than or equal with a gate voltage of the other transistor and an amplification factor of the gate voltage to an output voltage of the APC circuit is gradually reduced. In such a case, when the output voltage of the APC circuit becomes equal with or higher than a set voltage, the device is used in a high output mode but when the output voltage is lower than the set voltage, the device is used in a low output mode. COPYRIGHT: (C)2004,JPO
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