Transmisor outphasing en UHF usando amplificadores clase E a GaN HEMT
Document typeConference report
PublisherUnión Científica Internacional de Radio
Rights accessRestricted access - publisher's policy
A Chireix outphasing transmitter at UHF band is presented in this paper, based on class E RF power amplifiers. As recently proved in , properly transforming the load modulation path, imposed by the non-isolated combiner, into fundamental frequency impedan ce values at the device drain terminals as close as possible to those assuring zero voltage switching condition, good efficiency values may be kept along a significant output power range. A lumped element implementation of the amplifiers and the combiner, together with the use of GaN HEMTs, allowed controlling the output power over a 6 dB range with an efficiency value over 60%. Experiments with asymmetrical two tones, conceived as a discrete spectrum signal with a 1:4 envelope variation, have shown the capability of the arch itecture to be linearized using digital predistortion (DPD). In order to reproduce a spectrally efficient communication signal, with nulls in the envelope, a hybrid control strategy was employed, combining the outphasing between branches with amplitude variations of both RF excitation signals for the lower range of the envelope. Average drain efficiency and PAE values of 63% and 60.3% respectively have been measu red, for a 11.8 W and 5.06 dB PAPR WCDMA signal, while m eeting ACPR specifications.
CitationMarante, R. [et al.]. Transmisor outphasing en UHF usando amplificadores clase E a GaN HEMT. A: Simposium Nacional de la Unión Científica Internacional de Radio. "XXVII Simposium Nacional de la Unión Científica Internacional de Radio: libro de actas". Elche: Unión Científica Internacional de Radio, 2012.