New VT-designed antenna system is successfully demonstrated on one of the world's largest radio telescopes

A team of engineers and scientists from the National Radio Astronomy Observatory (NRAO) and Virginia Tech have successfully demonstrated a new antenna feed system for the Very Large Array (VLA). The VLA is one of the world's premier astronomical observatories, consisting of 27 25-meter dish antennas located in central New Mexico.

Satellite dishes

The new feed system was designed by Steve Ellingson, an associate professor in VT's department of electrical computer engineering, and Mahmud Harun, a VT Ph.D. student who graduated in 2011. The prototype installation and test program was led by Dr. Frazer Owen, a senior astronomer at NRAO.

The new feed system allows the VLA to observe continuously from 54-85 MHz, replacing a previous system with much narrower bandwidth and which was only intermittently installed due to interference with the VLA's higher-frequency systems. The new system avoids the interference problem by using four dipole-like elements lying outside the signal path used by the higher-frequency systems, and combining them to create signals equivalent to those from dipoles located in the nominal, but interfering, locations. The increased bandwidth is obtained by replacing the dipoles with a novel antenna element purpose-built for this application.