To provide a radio communication terminal, in which noise reduction and cost reduction of a dual-mode transmitter handling two modulation schemes of non-constant amplitude modulation and constant amplitude modulation can be realized.
By applying a phase-locked loop with respect to the output signal of an orthogonal modulator and a synchronization loop with respect to envelope, a low-noise transmitter adapted to the constant-amplitude modulation and the non-constant amplitude modulation is realized. Moreover, by preparing a variable gain amplifier for realizing envelope modulation and a variable gain amplifier for realizing output power control of a power amplifier, a general-purpose PA with a fixed gain can become usable, and thus cost reduction for the radio communication terminal can be achieved.
ITO MASAHIRO
KASAHARA MASUMI
WILLIAMS STEPHEN
TTP COMMUNICATIONS LTD
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