none

NRAO/Socorro Colloquium Series

Sivasankaran Srikanth

NRAO-CV


Broadband components for the JVLA Q-band receiver

The Q-band (40-50 GHz) receivers were installed on the VLA in the mid 90’s. The feed horn, polarizer etc. had limited bandwidth and there is performance roll-off at the band edges. The amplifiers were of the 4-stage design and have roll-off at the band edges as well. The Atlantic Microwave septum polarizers used on these receivers are showing signs of ageing because of temperature cycling. CDL has developed orthomode transducer, phase shifter and 5-stage amplifiers in the past few years as part of the development proposal of ALMA Band 1 cartridge. These components operate from 35-52 GHz range and have improved performance compared to the ones on the present receivers. These components also have better performance in the 38-40 GHz range as compared to the components on the Ka-band receiver, where there is roll-off of performance. Design and performance results of these components will be presented.



May 30, 2014
11:00 am

Array Operations Center Auditorium

All NRAO employees are invited to attend via video, available in Charlottesville 245, Green Bank Auditorium,  Tucson N525, and NTC 400.

Local Host: Steve Durand

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.