Switch-Mode Amplifier ICs with over 90% Efficiency for Class-S PAs using GaAs-HBTs and GaN-HEMTs

Published in:
IEEE MTT-S Int. Microw. Symp. Dig., Atlanta, GA, Jun. 15-20, pp. 751-754 (2008).
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Abstract:
This paper reports on design and realization of monolithic switch-mode amplifiers for data rates up to 1.8 Gbps, suitable for Class-S and inverse class-D PA modules. GaN HEMT as well as high-voltage GaAs-HBT technologies are employed and compared. For digital signal transmission without output filtering, the chips achieve efficiencies of more than 90 % at an output power of 5.4 W and 6.5 W with PAE values including the on-chip drivers, of 75% and 80% for GaAs-HBT and GaN-HEMT Ics respectively. These high efficiencies values are very promising since such PA chips represent the key building block for future class S systems.

Index Terms:
power amplifier, PAE, Class-D, Class-S, HBT, GaAs.

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