TRANSMITTER CIRCUIT, RADIO BASE STATION APPARATUS, AND WIRELESS TERMINAL APPARATUS

摘要

A transmitter circuit wherein low-cost D/A converters and LPFs exhibiting small power consumptions can be used for any one of narrowband and wideband transmission modes. In this transmitter circuit (100), during a narrowband transmission mode, two constant envelope signals generated by a constant envelope signal generating part (109) are inputted to respective ones of analog circuit parts (102,103), while the analog circuit parts are switched into a LINC amplification mode, thereby bringing power amplifiers (118,119) into B-class operations so as to enhance the efficiency. During a wideband transmission mode, two band division signals formed by inverse Fourier transforming parts (107,108) are inputted to the respective analog circuit parts, while the analog circuit parts are switched into a quadrature modulation combination mode, thereby causing a combiner (104) to combine outputs from the analog circuit parts, whereby low-cost D/A converters (110a,110b,111a,111b) and LPFs (112a,112b,113a,113b) exhibiting small power consumptions can be used to achieve a wideband transmission.