| 摘要 |
PROBLEM TO BE SOLVED: To provide an ET power amplification system to follow output of a DC-DC converter of an amplitude amplification unit even in sharp change of an envelope line component of RF (Radio Frequency) signals, stabilize the output of the DC-DC converter by a simple composition, and improve efficiency of a whole system. SOLUTION: The RF signal input to a coupler 1 is input to a linear power amplifier 3 through a delay circuit unit 2, and output as an amplified RF signal. Moreover, an amplitude component of the RF signal is extracted by an envelope line detection unit 4, amplified by the DC-DC converter 5, and supplied to a linear power amplifier 3 as power source voltage. At the time, a DC-DC converter control unit 6 compares a change degree of the envelope line component of the RF signal with a threshold value, switches a switching frequency of the DC-DC converter 5, and switches a phase compensation circuit connected to a feedback unit of an error amplifier of the DC-DC converter 5 according to the switching frequency. COPYRIGHT: (C)2008,JPO&INPIT
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