Micro-machined integrated waveguide transformers in thz pickett-potter feedhorn blocks

Kristina K. Davis, Jennifer Kloosterman, Christopher Groppi, Jonathan Kawamura, Matthew Underhill

Research output: Contribution to conferencePaperpeer-review

1 Scopus citations


We present laboratory measurements of a circular-to-rectangular waveguide transformer integrated into a 1.9 THz Pickett-Potter feedhorn detector block. This design is applicable for instruments where circularly symmetric feedhorns are required to mate with rectangular waveguide fed receiver devices. Compared to previous transformer segments machined into separate blocks or machined into split-block segments, we ensure axial alignment along the waveguide segments at the cost of rounding the edges of the rectangular waveguide. This architecture was fabricated by direct metal micro-machining, which offers significant advantages over competing techniques in complexity, timescale, and cost of manufacturing. All machining passes during manufacture can be made from the front of the block including the final waveguide segment. We compared simulations of the waveguide circuit performance using multiple electromagnetic software packages to finalize the dimensions of the optimized transformer module. A single pixel feedhorn-transformer module was manufactured on a 3-axis CNC milling machine. We tested integrated feedhorn-transformer modules using waveguide-fed hot electron bolometer mixers designed and fabricated at the Jet Propulsion Laboratory using a liquid helium-cooled cryostat. Beam patterns of the Pickett-Potter modules were measured using a high-power 1.9 THz multiplication chain as the source. We find good agreement between the simulated and laboratory beam pattern.

Original languageEnglish (US)
StatePublished - 2017
Event28th International Symposium on Space Terahertz Technology, ISSTT 2017 - Cologne, Germany
Duration: Mar 13 2017Mar 15 2017


Other28th International Symposium on Space Terahertz Technology, ISSTT 2017

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Computer Networks and Communications
  • Space and Planetary Science
  • Radiation
  • Electrical and Electronic Engineering


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