| 摘要 |
PROBLEM TO BE SOLVED: To provide a transmitting device in which a wide output controlling variable width as well as high efficiency can be obtained. SOLUTION: In the vicinity of maximum transmitting electric power, saturation mode operation is selected. While a large electric power amplifier 12 is operating in a saturation state by making an input level of the large electric power amplifier 12 lager to fix the level, amplitude components of modulation signals in the range depending on an output electric power control level are input to an R input terminal 33. Then, by applying amplitude modulation to an electrical source voltage VDD of an electrical source terminal 25, high-efficiency polar coordinate modulation is practiced. In the case of smaller transmitting electric power than the maximum one, a linear mode is selected. An input level of the large electric power amplifier 12 is made smaller to allow the large electric power amplifier 12 to operate linearly and by varying the electrical source voltage VDD of the electrical source terminal 25 depending on the output electric power control level, transmitting electric power control is performed. COPYRIGHT: (C)2005,JPO&NCIPI
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