Novel implementation topology for three level delta sigma modulation based transmitter

This paper presents a novel implementation topology of three- level delta sigma modulation (DSM) schemes. The delta sigma modulation converts envelope-varying signal to pulse modulated form, which can be applied directly to high efficient switch mode power amplifiers (SMPA). Multilevel DSM is proposed over bi-level DSM to enhance coding efficiency (CE) and signal to noise and distortion ratio (SNDR). However the quality of such multilevel pulse signal is degraded when signal is amplified using power amplifiers, which are nonlinear near saturation region. It defeats some of the advantages of using multi-level DSM. This paper proposes a topology that converts three-level signal to a bi-level level signal, which retains benefits of three-level DSM with less-distortion due to bi-level stage implementation when applied to PA.