Beam Waist Properties of Spiral Antenna Coupled HEB Mixers at Supra-THz Frequencies

Beam Waist Properties of Spiral Antenna Coupled HEB Mixers at Supra-THz Frequencies

Gaspar Silva, Jose Rui (SRON Netherlands Institute for Space Research; Rijksuniversiteit Groningen)
Finkel, M. (TU Delft QCD/DiCarlo Lab; SRON Netherlands Institute for Space Research)
Laauwen, Wouter M. (SRON Netherlands Institute for Space Research)
Yates, S.J.C. (TU Delft Tera-Hertz Sensing; SRON Netherlands Institute for Space Research)
Mirzaei, B. (TU Delft ImPhys/Optics; SRON Netherlands Institute for Space Research)
Vercruyssen, N. (TU Delft QN/Quantum Transport; SRON Netherlands Institute for Space Research)
Young, Abram (University of Arizona)
Walker, Christopher (University of Arizona)
Gao, J.R. (TU Delft ImPhys/Adam group; SRON Netherlands Institute for Space Research)

2023

We have simulated and measured the beam properties of lens-antenna coupled hot electron bolometer mixers at a few supra-terahertz frequencies between 1.4 and 5.3 THz. The quasi-optical structures consist of an elliptical lens and a logarithmic spiral antenna. The model used for our simulations consists of a finite-element analysis to simulate the far-field radiation pattern of the antenna, geometrical optics to map the antenna radiation to the lens surface, and physical optics to calculate an arbitrary far field. We perform a thorough study of the beam properties, such as beam waist radius, phase center location and axial ratio by varying the diameter and extension of the lens, and misalignments of the antenna relative to the lens, at different operating frequencies. The simulation results are applied to the design and optimization of three different lenses for mixers to be operated at 1.4, 1.9, and 4.7 THz, respectively, which will be used in the heterodyne array receivers on board of NASA's balloon borne GUSTO observatory. The beam properties were verified experimentally by measuring the beam patterns in amplitude at multiple planes using a heterodyne technique. We found that the experimental results show good agreement with those from the simulations. Our work has delivered the mixers with the required beam characteristics for GUSTO.

Antenna arrays
antenna radiation pattern
cryogenic
lenses
terahertz (THz) radiation

http://resolver.tudelft.nl/uuid:55ab9048-14c5-4d5d-bf62-f49d84d0c9ce

https://doi.org/10.1109/TTHZ.2022.3230742

2023-06-20

2156-342X

IEEE Transactions on Terahertz Science and Technology, 13 (2), 167-177

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Institutional Repository

journal article

© 2023 Jose Rui Gaspar Silva, M. Finkel, Wouter M. Laauwen, S.J.C. Yates, B. Mirzaei, N. Vercruyssen, Abram Young, Christopher Walker, J.R. Gao, More Authors