High efficiency transmitter using varactor based dynamic load modulation

This paper presents results for a dynamic load modulation transmitter where an existing 1 GHz LDMOS power amplifier is combined with a varactor based tuneable load network to produce a dramatic efficiency improvement for modulated signals. The transmitter is combined with a dedicated linearization method to achieve an average PAE of 53% for a WCDMA signal at 7 dB PAPR. The results demonstrate the potential of dynamic load modulation for future transmitters combining flexibility and high efficiency at a low cost.

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