Low frequency dithering technique for linearization of current mode class D amplifiers

Abstract

Combination of a band-pass signal with a low frequency sinusoid signal, also known as dithering, will linearize the performance and reduce the reactive power loss of class D amplifiers. The expectations are verified through realization and measurement of a 2 watt current mode LDMOS class D amplifier operating at 2.014 GHz. The drain efficiency is enhanced from 55 to 59 percent, while giving ACPR levels below −33dBc for first WCDMA adjacent channel.