AlGaN/GaN MMICs for Robust Communications Receivers

In space applications, due to the large number of sources of interferences, RF receivers have to be as robust as possible to maintain good operation of the satellite. The system must maintain its performance under severe jamming conditions and the performance must not degrade when exposed to high input powers. To address the receivers’ robustness, LNAs and Mixers have been designed and fabricated in the frame of an European project. TNO and TAS-F have been in charge of the amplification and mixing parts respectively. Three frequency bands are targeted for these designs: C-, Ku- and Ka-band. Gallium Nitride [8] has the advantage of high power capabilities and low noise performance, which makes it an excellent candidate for robust satellite receivers. High survivability levels for LNAs by using GaN technology has already been proven by others [1]-[7]. Regarding mixers in GaN, only a few designs have been published [9]. For both MMICs, the AlGaN/GaN technology is used with gate length of 0.25 μm and 0.15 μm provided by Fraunhofer IAF. The measured performance for the LNAs is a noise figure of 1.2, 1.9 and 4dB for the C-, Ku- and Ka-band respectively, with a gain of 21, 19.8 and 18dB. For the Mixers, the conversion losses are 10, 9 and 12dB with a 12, 11 and 8dBm for the input 1dB compression point. This paper presents the design and measurement results of the C-, Ku-, Ka-band LNAs and Mixers