From 100 GHz to terahertz electronics - activities in Europe

This paper presents an overview on selected results in the area of millimeter-wave and submillimeter-wave integrated circuits and devices in Europe for application in the frequency range between 100 GHz and 2 THz. Advanced integrated circuits for millimeter-wave applications based on metamorphic InAIAs/InGaAs HEMTs on 4"" GaAs substrates were developed and manufactured at the Fraunhofer Institute IAF. An extrinsic transit frequency of 410 GHz for 50 nm gate length devices is achieved. Two-stage low-noise amplifiers demonstrate a small signal gain of 20 dB and a noise figure of 2.4 dB at 94 GHz. An amplifier MMIC developed for G-band operation exhibits a gain of 21 dB at 220 GHz. These results arc compatible with those achieved using state-of-the-art InP-based HEMT technologies. Recent results of HBVs (Heterojunction Barrier Varactors), Schottky diodes and HEBs (Hot-Electron Bolometers) for signal generation and detection up to terahertz frequencies obtained by various research groups in Europe are presented.