Optics & Electromagnetic Components - Increasing the bandwidth

PShifter.JPG

Set of waveguide phase shifters designed by the CDL and electroformed by the CDL Chemistry Lab.

Receiver optics and electromagnetic (EM) components, in addition to the active components in a receiver, contribute to the sensitivity, beam quality and polarization purity of radio telescopes.  Examples of passive components include feed horns, orthomode transducers (OMT), phase shifters etc.  All these components that went into the VLA upgrade receivers were not commercially available and were mostly developed and manufactured at the CDL.  This is also true for some bands of ALMA and all of the GBT and VLBA receivers.  Over the years the development efforts have yielded not only broader bandwidths but also simpler mechanical designs that have led to lower cost of manufacturing.  CDL developed EM components have found their place in receivers on various astronomical instruments around the world like the Efflesburg 100-m telescope, the Shanghai 65-m telescope, Torun 32-m telescope to name a few.  Electromagnetic simulation tools are routinely used in the development of components and the design is validated with measurements.  CDL also has the capabilities to do analysis of reflector antennas fed from either prime focus or secondary focus.

CDL EM Component Development Areas:

•  Develop wideband  feeds and polarizers for future receivers

•  Develop feeds and optics for THZ receivers

turnstile_junction.jpg

Measuring S-parameters of a 67-92 GHz turnstile junction orthomode transducer

feed_horn.jpg

Radiation pattern measurement of L-band feed horn designed for JVLA.

OMT.JPG

11-18 GHz OMT developed and fabricated by the CDL for the GBT galactic center pulsar receiver.

Connect with NRAO

The National Radio Astronomy Observatory and Green Bank Observatory are facilities of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.

The National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."

AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.