Multilevel Power Supply for High Efficiency RF Amplifiers

M. Vasic, O. Garcia, J.A. Oliver, P. Alou, D. Diaz, J.A. Cobos
2009 2009 Twenty-Fourth Annual IEEE Applied Power Electronics Conference and Exposition  
In radio systems linear power amplifiers (class A, B or AB) are usually used as a solution for the power amplifier stage. These amplifiers have high linearity, but suffer from low efficiency when the transmitted signal has low peak-to-average power ratio. The Kahn envelope elimination and restoration (EER) technique is used to enhance efficiency of RF transmitters, by combining highly efficient, nonlinear RF amplifier (class D or E) with a highly efficient envelope amplifier in order to obtain
more » ... inear and highly efficient RF amplifier. This paper presents a solution for the envelope amplifier based on a combination of multilevel converter and linear regulator. The proposed solution can reproduce any signal with maximal spectral component of 2 MHz and give instantaneous maximal power of 50 W. The efficiency measurements show that when the signals with low average value are transmitted, it has up to 15% higher efficiency than linear regulator that is used as a conventional solution. Additionally, the algorithm for selection of voltage levels for the multilevel converter is explained, as well.
doi:10.1109/apec.2009.4802821 fatcat:lngvuprykzctjk7ywmsbdsgms4