Class-D power amplifiers using LDMOS and GaN power devices: a comparative analysis

This paper provides new analytical expressions for the prediction of efficiency and power added efficiency in current mode class-D (CMCD) power amplifiers (PAs). Derived from a switch-based model which includes 9 parasitic elements, these expressions are then used to compare two device technologies in silicon and GaN in a 60W, 2.5GHz CMCD PA. This study reveals that the knee voltage and the drain and source resistances are mainly responsible for the lower PAE of the LDMOS device in comparison to GaN.