300 GHz to 1.2 THz GaAs Schottky membrane TMIC’s for next generation space missions
Paper in proceedings, 2013
For future earth observation and planetary exploration missions (e.g. STEAMR, MetOp, GEOSOUNDER, SWI, FIRE, GEOSTAR), high performance room-temperature heterodyne receivers in the 50 GHz to 1.5 THz frequency range are needed. For frequencies up to 300 GHz, GaAs and InP HEMT technology has today become competitive, offering high sensitivity along with all the benefits of traditional MMIC designs, e.g. multifunctional chips and high repeatability. For frequencies let say above 300 GHz, GaAs Schottky diode technology can offer an unprecedented noise performance along with the versatility of working both as a source and detector. The long track record and high reliability of Schottky diode receiver technology makes it the natural choice for high-performance room-temperature space instrumentation operating in the THz range.
To fully benefit from the performance that Schottky diode technology can offer, monolithically integrated circuit (MIC) membrane technology [1-3] is necessary. By monolithic integration of THz Schottky diodes on ultrathin substrates and using freestanding metal beam leads, low loss transmission line structures suitable for waveguide integration assembly (waveguide probes, DC and RF interconnects etc.) become possible. Terahertz Membrane Integrated Circuits (TMIC’s) have proven to operate well up to several THz overcoming many of the problems and limitations associated with hybrid technology (using discrete flip chip mounted diodes). Thereto the superior repeatability of TMIC technology opens up for the possibility of multichip integrated assemblies and system on chip solutions, which in turn can enable completely new instrument concepts. We will present on the progress of our GaAs Schottky technology based radiometer systems and the development of monolithically integrated multipliers and mixers based on the Chalmers diode membrane process. Specifically we will present ongoing work from the STEAMR instrument development operating at 340 GHz, as well as on the development of 664/1200 GHz receiver prototypes relevant to upcoming space missions.