A novel inverse class-D output matching network and its application to dynamic load modulation

M. Gamal El Din, Bernd Geck, Ilona Rolfes, Hermann Eul

2010 IEEE MTT-S International Microwave Symposium Digest (MTT), pp. 332-335, Anaheim, California, May 23-28, 2010


This paper presents a new inverse class-D output matching network suitable for dynamic load modulation. The proposed matching network can synthesis the optimum load impedance at the fundamental as well as the necessary terminations at the 2nd and the 3rd harmonic, additionally it allows separate control over the imaginary and real part of the admittance at the fundamental. For load modulation applications an adaptive ?/4 line will be presented. An inverse class-D GaN power amplifier at 1 GHz based on the new output matching network is designed and measured. The measured amplifier has a maximum power added efficiency of 74% and maximum output power of 40 dBm. Through using the adaptive ?/4 line the amplifier can achieve a PAE of more than 50% at an output power of 32 dBm, which gives an efficiency improvement of more than 25% over an 8 dB output dynamic range.

[IEEE Library]

Tags: matching, network