A Contribution to Linearity Improvement of a Highly Efficient Pa for WiMAX Applications
In this paper, the authors describe the design of a highly efficient and linear GaN HEMT power amplifier which may be used in WiMAX application. To improve linearity of highly efficient power amplifiers, a technique using diodes in the gate DC path was applied to TL and 2HT amplifier. This solution using diodes offers a good manner to improve linearity near saturation zone compared to the approach using only a DC gate resistor for TL (Tuned Load) case as well as for 2HT (Second Harmonic Tuning approach). A 2.5GHz 2HT power amplifier circuit was built, and measured data confirm the linearity improvement, particularly near saturation zone, as predicted by simulation, maintaining higher power performances.