Naoki Kosaka

Internally matched GaN FET at C-band with 220W output power and 56% power added efficiency

In this paper, a high power and high efficiency fully internally-matched GaN FET operating at C-band is presented. In this work, a C-band GaN amplifier is designed so that 2nd harmonic impedance is tuned to high efficiency and combining loss is maintained minimum. As a result, 224W output power and 56% power added efficiency was successfully obtained, which is the highest efficiency as for over 200W GaN amplifier operating in C-band.

A high-efficiency and high-gain, plastic packaged GaN HEMT for 3.5-GHz-band LTE base stations

A plastic packaged GaN HEMT is presented for 3.5-GHz-band LTE small-cell base-station applications. A pair of GaN HEMT dies and MIM capacitors is assembled in the package for Doherty amplifier use. Optimized drain bonding wire length enhances high efficiency operation. The input prematching with the MIM capacitors suppresses insertion loss and improves power gain. Measurements of a single-chain amplifier using the GaN HEMT show a high drain efficiency of 66.3% and a high power gain of 16.2 dB at 3.5 GHz, regardless of plastic packaging. A Doherty amplifier demonstration with the GaN HEMT shows a drain efficiency as high as 51.2% and an output power of 36.0 dBm at ACLR of -50 dBc. This is the first demonstration of a plastic packaged GaN HEMT Doherty amplifier in the 3.5-GHz band.