A 520–620-GHz Schottky Receiver Front-End for Planetary Science and Remote Sensing With 1070 K–1500 K DSB Noise Temperature at Room Temperature

A state-of-the-art 520-620-GHz receiver front end working at room temperature was designed, built, and measured. The receiver front-end features a GaAs-Schottky diode-based subharmonic mixer and a 260-307-GHz doubler, both fabricated with the new LERMA-LPN Schottky process on a 4- μm-thick GaAs membrane suspended in a waveguide with metal beamleads. Small-area mesas and optimized transmission lines with low dielectric loading are used. At 295 K ambient temperature, an average of 1284 K DSB receiver noise temperature was measured over the 520-620-GHz frequency range, including the 3.5-8.5-GHz IF chain loss. A record 1130 K minimum DSB receiver noise temperature at 557 GHz was measured. At 134 K ambient temperature, an average DSB receiver noise temperature of 685 K from 538 to 600 GHz was measured when correcting for the cryostat window loss. A minimum DSB receiver noise of 585 K was measured at an RF center frequency of 540 GHz. The 520-620-GHz receiver presented in this article allows an increase in the sensitivity of the JUpiter ICy Moons Explrorer-SWI instrument of about a factor of two compared with requirements. It will allow study of the Jovian system with particular emphasis on the chemistry, meteorology, structure, and atmospheric coupling processes of Jupiter and its icy satellites, thereby providing important data for the exploration of their habitable zones.