Duration: 18 months
Millimetre-wave (mm-wave) and THz radiometers are critical instruments in Earth Observation (EO) and scientific payloads. Examples of such instruments include those on board the MetOp-SG satellites, such as the MWI, MWS, or the ICI [1]. These instruments operate at frequencies ranging from a few GHz up to several hundred GHz, with specific interest in bands like 183 GHz, 243 GHz, 325 GHz, 448 GHz, and 664 GHz, which are also planned for future ESA remote sensing instrument payloads. Recent advances in semiconductor technology have enabled the development of LNAs at such frequencies [2], making direct detection feasible above 100 GHz. By eliminating the need for LO systems and bulky IF filter-banks, direct detection allows for more compact and efficient designs, which is particularly beneficial for arrays of direct detectors or small satellites, where space and power constraints are critical.
This project will leverage TERASi®’s unique system in package (SiP) and AirCore™ technologies to deliver compact, high-efficiency THz RF frontends for EO applications. Integrated THz systems face significant challenges due to the high precision required in building and assembling waveguide components.
To address these issues, we will develop a demonstrator of an integrated radiometer frontend operating at 325 GHz. This frontend will combine an antenna, LNA, and filter in a single package. Our approach's core innovation is using silicon micromachining as a packaging technology, replacing traditional CNC-milled blocks. This method enables precise fabrication of complex waveguide structures for antennas and filters in a compact package, while also accommodating the LNA. This provides optimal performance through reduced connections between system components alongside significantly reduced size and weight of the radiometer frontend. This development marks a crucial step towards fully integrated modules, paving the way for next-generation radiometers.
[1] https://www.eumetsat.int/metop-sg
[2] S. Diebold et al., "Low noise amplifier MMICs for 325 GHz radiometric applications," 2014 Asia-Pacific Microwave Conference, Sendai, Japan, 2014, pp. 151-153.
[3] A. Gomez-Torrent et al., "A 38 dB Gain, Low-Loss, Flat Array Antenna for 320–400 GHz Enabled by Silicon-on-Insulator Micromachining," in IEEE Transactions on Antennas and Propagation, vol. 68, no. 6, pp. 4450-4458, June 2020, doi: 10.1109/TAP.2020.2969753.
[4] O. Glubokov, X. Zhao, J. Campion, U. Shah and J. Oberhammer, "Micromachined Filters at 450 GHz With 1% Fractional Bandwidth and Unloaded Q Beyond 700," in IEEE Transactions on Terahertz Science and Technology, vol. 9, no. 1, pp. 106-108, Jan. 2019, doi: 10.1109/TTHZ.2018.2883075
