Abstract

Two different concepts for high efficiency linear amplification of variable envelope RF signals are presented. The EER concept is based on a Class-E PA, and it has been demonstrated that excellent ACPR performance can be achieved. The Class-E PA employs a GaAs HBT device and the simulated PAE is higher than 70% at 2 GHz. The wideband linearization feature of the “Limit Duty Cycle Modulation” technique, in conjunction with the applicability of the switching type amplifiers enables the realization of a new kind of transmitter architecture that facilitates the optimization of linearity and power-efficiency. A suitable limit duty cycle configuration for broadband communication applications is introduced and considered in some depth.