A Compact Ultra-broadband GaN MMIC T/R Front-End Module

This paper presents the design and the measured results of a monolithic microwave integrated circuit (MMIC) T/R front-end module (FEM) suitable for S band to Ku band applications, using a 0.1µm GaN HEMT process. For the first time, the design successfully integrated a 3-stacked non-uniform distributed power amplifier (SNDPA), a two-stage 2-stacked low noise amplifier (LNA) and a T/R switch in one MMIC, to obtain the ultra-broadband power response in Tx mode and low-noise low-consumption performance in Rx mode, simultaneously. Measured results of the MMIC T/R FEM across the 2 to 18 GHz band show that a noise figure (NF) lower than 3.5 dB and a gain better than 18 dB in Rx mode. Meanwhile, about 39 dBm output power at least 16.5 ± 2 dB small-signal gain and average 20% power add efficiency (PAE) have been achieved in Tx mode. The chip occupies a die area of 2.5 × 3.2 mm2. To the best of the authors' knowledge, this work reports the first T/R MMIC FEM which covers the frequency range of 2 to 18 GHz and achieves about 8 W output power and lower than 3.5 dB NF with the smallest die size among all published chips to date.