| 摘要 |
There is provided a wide-band and highly efficient transmitter of the EER method. For this, an amplitude component of a modulation signal is input to a power source terminal of a high- frequency power amplifier (130) and an IQ quadrature signal is input to a high-frequency input terminal of the high-frequency power amplifier (130), so that the original modulation signal is obtained from the output of the high-frequency power amplifier (130). Collector voltage is supplied to an emitter follower (729) via a switch group (621) from a DC-DC converter group (615) having successively different output voltages. For the collector voltage, one of the outputs of the DC-DC converters (616 to 620) is selected by the switch group (621) according to the amplitude component level and supplied to the emitter follower, so as to reduce the difference between the emitter voltage of the emitter follower (729) and the collector voltage of the emitter follower (729), thereby increasing the efficiency of the emitter follower (729). The power source voltage of the high-frequency power amplifier (130) is voltage-converted by the emitter follower (729) so as to enable wide-band operation.
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