100 W highly efficient octave bandwidth GaN-HEMT power amplifier

In this contribution, the design, implementation, and experimental results of a high-efficiency broadband GaN HEMT power amplifier are presented. Optimum fundamental and harmonic load impedances were obtained using load-pull simulations for the active device across the design bandwidth. A systematic approach was applied for the design of wideband output and input matching networks. Continuous wave (CW) large-signal measurement results showed that across 1.1-2.0 GHz (58 % bandwidth), the output power was higher than 110 W, and 50-72% drain efficiency was achieved. Over the octave bandwidth of 1.0-2.0 GHz, at least 84 W output power was measured. The power gain was around 12 dB. An ACLR of -45 dBc was measured for an LTE signal at 42 dBm average output power under additional digital predistortion (DPD).

I. Introduction

Nowadays highly efficient broadband power amplifiers are mandatory in almost all communications systems. Especially the various telecommunication standards require linear power amplifiers with large bandwidth and high efficiency. Even higher power is necessary for broadcasting systems like DVB and DAB. With an increasing power of the transmitter the significance of the efficiency grows. A highly efficient power amplifier can save a high amount of operational costs.