The Albuquerque IEEE Joint Chapter presents the talk: The Low-Noise Receiver Systems Developed for the EVLA.

Presented by: Bob Hayward, NRAO Senior Engineer (Retired), Socorro, NM.

Time: 7:30 pm Wednesday, October 22, 2014. Social hour begins at 5:45 pm. Dinner begins at 6:30pm.

Location: The Canyon Club (was Four Hills Country Club), 911 Four Hills Road SE, Albuquerque.

Dinner Menu: Soup of the Day, Top Sirloin, Asparagus, Garlic Mashed Potaoes, Dinner Rolls/Butter, Chef’s Choice Dessert, Coffee, Iced Tea and Water.

Cost: There is no charge and no reservation required to attend just the talk. $25 per person for dinner (full-time student members of IEEE, $15). reservations required. RSVP by email to or phone Mike Harrison at (505) 239-2663.

PLEASE NOTE: This dinner meeting will be held at The Canyon Club which requires a pretty accurate number of meals to prepare by noon on Monday before the Wednesday meeting. Please try to make your reservation by Monday, October 20. The Canyon Club is often flexible so it is worth trying to make a late reservation.

Presentation Summary: The Very Large Array (VLA), located less than an hour’s drive west of Socorro, NM, is widely regarded as the world’s most scientifically productive radio telescope. Operated by the National Radio Astronomy Observatory (NRAO), this aperture synthesis interferometer consists of 27 movable antennas, each 25 meters in diameter, which can be configured to provide the resolution of an antenna whose size can range from 1 to 36 kilometers in width. When commissioned in 1980, the VLA could only observe celestial sources in four narrow frequency bands centered at 1.5, 4.7, 15 and 23 GHz. Over the next 20 years, its receiver systems were incrementally improved
to give the Array better sensitivity and wider frequency coverage. But as the 21st century dawned, the VLA’s performance was still limited by its 1970’s era technology.

The recently completed Expanded Very Large Array (EVLA) project has provided many major enhancements, including the installation of 240 new, state-of-the-art, low-noise, cryogenic receivers that now enable astronomers to observe at any frequency between 1 and 50 GHz and with bandwidths as wide as 8 GHz, some 80 times broader than before. Over the 10 year long EVLA upgrade effort, the author was deeply involved in the design and testing of the prototype receiver hardware as well as the production of several of the new receiver bands. This talk will discuss the EVLA’s front-end systems and the innovative solutions developed by the various NRAO design teams to meet the
demanding performance goals required for the project, including such critical microwave components as the broad-band feeds, circular polarizers, low-noise amplifiers and multifunction MMIC modules. Finally, an explanation of the system tests that were used to evaluate the cryogenic receivers will be presented.

If time permits, the talk will also attempt to put the VLA into historical context by briefly discussing the early days of radio astronomy and radio interferometry, as well as describing the evolution of the VLA’s low-noise receiver system from its inception to the present day.

About the Speaker: About the Speaker: Bob Hayward has spent over 3 decades developing digital spectrometers and low-noise receiver systems for radio telescopes. He was born in Nova Scotia, Canada. He received his BSc in Physics in 1977 from Dalhousie University and
his MSc in Radio Astronomy from Queens University in 1981. He began his career in radio astronomy instrumentation in 1979 when he joined the Herzberg Institute of Astrophysics in Ottawa as a digital engineer supporting the 150-ft telescope at the Algonquin Radio Observatory (ARO). His was placed in charge of the construction, testing and system integration of the ARO Auto-Correlation Spectrometer which contained over 3,000 ECL, TTL and CMOS integrated circuits. In 1986 he was named the Project Engineer for the pair of 345 GHz receivers which HIA developed for the 15-meter James Clerk Maxwell Telescope Telescope (JCMT) in Hawaii. He left Canada in 1996 and
moved to Tucson, AZ, to become the Chief Engineer at the10-meter Sub-Millimeter Telescope Observatory (SMTO).

In 1999 he joined the National Radio Astronomy Observatory (NRAO) in Socorro, NM, where he spent the next 13 years designing, building, testing and maintaining receiver systems for the Very Large Array (VLA) and the Very Long Baseline Array (VLBA). His first job was to act as the lead engineer in the development of new 80-96 GHz W-Band receivers for the VLBA. From 2004 to 2008 he managed the Front-End and Feed Systems element of the Expanded Very Large Array (EVLA) upgrade project which required the prototype design of 8 new receiver bands and the construction of a total of 240 low-noise cryogenic receivers.He was also the lead engineer on the development of the new L, K,
Ka & Q-Band EVLA receiver systems.

Bob retired from NRAO In 2012 as the Senior Engineer for Front-End Systems in Socorro. Since then he has spent his newly found free time doing historical research into some of the more obscure stories in the history of radio astronomy instrumentation. Bob became a member of the IEEE in 1980. From 1993 to 1996 he was the Secretary of the Canadian National Committee for the International Union of Radio Science (CNC /URSI).

Chapter Officers for 2014:

Chairman: Everett Farr (505) 846-0956
Vice-Chair: Michael Harrison (505) 239-2663
Treasurer: Paul Cravens (505) 730-3397
Secretary: This office is currently unfilled. There are few responsibilities. It would look good on someone’s Resume’.
EMC Liaison: Bud Hoeft (505)889-9705
MTT-S Liaison: George Oltman (505)299-3369
NPSS Liaison: Jane Lehr (505) 277-0298