| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that, in the conventional polar loop transmission circuit, two feedback circuits, that is, an amplitude feedback circuit and a phase feedback circuit, operate at the time of transmission, and consumption current becomes large especially at a low power level, and in one wherein the amplitude is controlled by an open loop control and only the phase is controlled by a closed loop control, a complicated table is necessary to correct the non-linearity of an input amplitude-amplitude characteristic and an amplitude-phase characteristic of a power amplifier, and therefore there were difficulties in implementation. SOLUTION: At a high power level at which the non-linearity of the power amplifier is strong, a polar loop transmission circuit is operated wherein two feedback circuits, the amplitude feedback circuit and the phase feedback circuit, operate. At an intermediate and low output level, consumption current at the intermediate and low output level is reduced by controlling the amplitude by open loop control. COPYRIGHT: (C)2008,JPO&INPIT
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