Abstract:
The Jet Propulsion Laboratory is a Federally Funded Research and Development Center managed by the California Institute of Technology and funded by NASA. The core institutional focus is the delivery of large-scale probes for robotic space exploration with recent examples including Europa Clipper, NISAR, and Psyche. In addition to this primary objective, the institution is also heavily invested in the maturation of next generation technologies for use in future spaceborne missions. This talk will highlight the development progress of millimeter-wave gas sensing systems deploying custom complimentary metal-oxide semiconductor (CMOS) integrated circuit elements.
Gas sensors that operate in the millimeter region of the electromagnetic spectrum (~180 GHz, 6 cm-1 ) represent a promising class of in situ sensing instrumentation having numerous planetary science applications [1-3]. These sensor platforms offer several unique capabilities including measurements over wide dynamic pressure ranges, fast acquisition speeds, and high selectivity to molecular species. Several technologies developed under NASA funded programs have allowed for significant reduction in the size and power consumption of these platforms without making sacrifices in system sensitivities. A specific set of key components include intrinsically small and low power consumption CMOSembedded millimeter-wave pulsed transmitter and heterodyne receiver integrated circuit chips. These custom sources/detectors are interfaced directly to a resonant sample cavity that is used to passively enhance molecular emission signals while also optimizing system geometry.
This talk will highlight the current state of the art for this emerging class of instrumentation detailing a dual-band system capable of detecting pure rotational transitions of both H2O (at 183.310 GHz) and HDO (at 80.358 GHz) to allow for localized determinations of H/D ratios. A full system description will be provided along with an introduction to the pulsed-emission detection scheme leveraged by the miniaturized spectrometer. Performance properties of the pulsed transmitter and heterodyne receiver chip set (viz. Fig. 1) will be discussed along with details of how generated radiation is coupled into (and out of) a resonant optical cavity. These results will be accompanied by demonstrative examples of molecular detections and discussion of future plans for testing in relevant planetary science environments.