Transmisor polar en UHF integrando un modulador de envolvente conmutado asistido por etapa lineal y un amplificador clase E a GaN HEMT

URSI 2012, XXVII Simposium Nacional de la Unión Científica Internacional de Radio, ElcheSpectrally efficient wireless communication standards impose stringent linearity specifications, which would require traditional IQ transmitters to operate with back-offed and power inefficient linear RF power amplifiers (PAs). In order to overcome such a significant limitation, alternative architectures have been proposed, as those based on the Envelope Elimination and Restoration (EER) technique. In this paper, a UHF polar transmitter is presented, combining switching and linear stages in the envelope amplifier as to achieve both great bandwidth and high efficiency, when drain modulating a GaN HEMT class E RF PA. Several tests, using EDGE, TETRA, and WCDMA standards have been performed with good result