Wireless quadrature modulator transmitter using E/O and O/E connectives

摘要

A transmitting circuit apparatus has a first digital modulator and a second digital modulator for modulating an I signal and a Q signal which are multi-valued digital baseband modulation signals, into a digital I signal and a digital Q signal, respectively, having the number of bits smaller than that of the baseband modulation signals; and a quadrature modulator for outputting a signal synthesized from the signals generated by modulating (two) carrier waves each having a phase perpendicular to each other by using the modulated I and Q signals, respectively.