Abstract

RFMD has developed 400W pulsed output power GaN HEMT amplifiers operating over 2.9GHz to 3.5GHz band or 17% bandwidth. Under pulsed RF drive with 10% duty cycle and 100s pulse width, the amplifier delivers output power in the range of 401W to 446W over the band, with drain efficiency of 48% to 55% when biased at drain voltage of 65V. The amplifier uses AlGaN/GaN HEMTs with a total device periphery of 44.4mm and advanced source connected field plates for high breakdown voltage. These wideband high power amplifiers are suitable for use in frequency agile pulsed applications such as military radar, air traffic control radar, and communications jamming.

Introduction

The high power and wide bandwidth potential of GaN HEMT devices is well known.1 RFMD has been developing high power amplifiers using GaN HEMTs for various applications. A 250W amplifier in the 2.14GHz to 2.5GHz band for wireless infrastructure applications in the WCDMA and WiMAX bands was reported earlier.2 Such wide bandwidth is essential for next generation frequency agile software-defined radio architectures that use reconfigurable radios to support multiple frequency bands and various standards.