A concurrent dual band 870 and 1970 MHz 10 W envelope tracking PA designed by a WCDMA probability distribution conscious approach

In this paper we propose a novel approach for the design of a concurrent dual-band power amplifier (PA) optimized for envelope tracking (ET) operation. The design was based around the WCDMA probability distribution function and implemented through a multi-section transmission line matching technique. This technique was applied to a concurrent 870 and 1970 MHz ET PA designed around a GaAs HEMT. The ET friendly design method has proven capable to enhance the average efficiency by a 2.2 factor over a signal bandwidth of 140MHz and 60MHz in the two carrier frequency bands respectively for the specific WCDMA signal. A detailed discussion of the design method and the validating experimental results are reported.