Thales Designs GaN PA For European MAGNUS Program

Thales UK, a company operating in aerospace, defence and space industries, has designed a GaN monolithic microwave integrated circuit (MMIC) power amplifier (PA) for the MAGNUS program, a European Defence Agency project aimed at developing European-sourced application technologies for advanced radar, communications and electronic warfare systems covering the electromagnetic (EM) spectrum from 2-18 GHz.

Thales UK was responsible for the design of 10 W GaN monolithic microwave integrated circuit (MMIC) power amplifiers based on the United Monolithic Semiconductors (UMS) 0.25 µm foundry process, as well as packaging and thermal analysis tasks. Once the MMICs had been realized and packaged, they were used to design a demonstrator unit, which Thales UK then leveraged to design a 30 W microwave power module (MPM).

The goals for this design were a frequency range of 6-18 GHz, 10 dB gain, and 10W output power. It was decided to use a non-uniform distributed amplifier topology, which is suited for broadband operation because it is inherently stable. The goal was to design two distributed amplifiers on a chip between a pair of splitter/combiner networks. For the first foundry run the amplifiers were combined off chip and for the second run the combining was done on chip.

MMIC designs were carried out using NI AWR Design Environment, specifically Microwave Office circuit design software, the passive structures were simulated using AXIEM 3D planar EM simulator, and the package was analysed with Analyst 3D finite element method EM simulator.

“Our design and simulation efforts showed that the UMS PDK, as well as the Microwave Office and Analyst models, were very accurate, which led to the success of this project,’’ said Rashid Fazaldin, microwave design engineer at Thales UK.