A Cartesian Sigma-Delta Transmitter Architecture

摘要

This paper proposes a transmitter architecture that enables high Peak to Average Power Ratio (PAPR) signals transmission with good linearity and efficiency. The architecture is based on the principle of transforming a non constant envelope modulated signal in a constant one using lowpass Sigma-Delta (∑△) modulators on the In-Phase and Quadrature baseband signal components. This conversion enables the use of a switched mode power amplifier which increases the transmitter power efficiency. Cartesian ∑△ architecture performances have been studied and compared to those obtained with a Polar Sigma Delta transmitter architecture.