NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Symmetric Waveguide Orthomode JunctionsImaging applications at millimeter and submillimeter wavelengths demand precise characterization of the amplitude, spectrum, and polarization of the electromagnetic radiation. The use of a waveguide orthomode transducer (OMT) can help achieve these goals by increasing spectral coverage and sensitivity while reducing exit aperture size, optical spill, instrumental polarization offsets, and lending itself to integration in focal plane arrays. For these reasons, four-old symmetric OMTs are favored over a traditional quasi-optical wire grid for focal plane imaging arrays from a systems perspective. The design, fabrication, and test of OMTs realized with conventional split-block techniques for millimeter wave-bands are described. The design provides a return loss is -20 dB over a full waveguide band (40% bandwidth), and the cross-polarization and isolation are greater than -40 dB for tolerances readily achievable in practice. Prototype examples realized in WR10.0 and WR3.7 wavebands will be considered in detail.
Document ID
20040021389
Acquisition Source
Goddard Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Wollack, E. J.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Grammer, W.
(National Radio Astronomy Observatory Charlottesville, VA, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Subject Category
Astrophysics
Meeting Information
Meeting: National Radio Astronomy Observatory Users Committee
Location: Socorro, New Mexico
Country: United States
Start Date: June 12, 2003
End Date: June 14, 2003
Sponsors: National Radio Astronomy Observatory
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Document Inquiry

Available Downloads

There are no available downloads for this record.
No Preview Available