Transmitter utilising bandpass delta-sigma modulator and switching mode power amplifier

In this paper a concept of a transmitter using delta-sigma modulation and switching mode power amplifier is presented. The specifications of a WCDMA base station transmitter are as an objective. Using a delta-sigma modulation in a D/A conversion, most of the nonlinearities of a multi-bit D/A converter are avoided. In addition the 1-bit output signal of the delta-sigma modulator is suitable for power efficient switching mode power amplifiers. The use of the images of the signal is studied as a method to reduce the required sampling frequency. The problems and possible solutions in implementing a wideband transmitter with this topology are discussed as well.