Investigation of Integrated Smooth Transistor’s Switching Transition Power Amplifier—2.4-GHz Realization of Class- $E_{M}$

This paper proposes a design technique for the implementation of a class-E
_M
power amplifier (PA). Class-E
_M
mode of operation has been proposed as an improved version of class-E in terms of efficiency and power gain, provided that the current fall time of switch is an appreciable portion of a period; the frequency of operation is high enough that the switching time of transistor can no longer be considered instantaneous. A novel approach for harmonic injection required for class-E
_M
operation is proposed, followed by the system of equations and the design methodology governing the proposed circuit. As a proof of concept and verification of the proposed design method, a class-E
_M
PA is designed and implemented in 0.25-μ m gallium arsenide pHEMT technology. The fabricated class-E
_M
PA operates at 2.4 GHz and delivers a power of 30 dBm to the load, with the power-added efficiency of 60% and a 14-dB power gain.