GTRI VIDEO HISTORY:
GTRI "The Solution Institution"

75th anniversary video
The history of GTRI is one filled with intrigue, innovation and impact. Learn about GTRI's exciting past, present and future. View video
FEATURES

GTRI's Modern History

Check out some of the problems GTRI experts have solved over the past 12 years.Case studies
Read all about it

Read all about it!

News releases, research magazines, employee newsletters and more - dating back to the 1950s.Publications

Share Your History!

GTRI wants your stories, documents, photos, videos and other historical items. Share them today!Tell us your story

Compact radar range tests antenna performance

An army tank undergoes testing at what was believed to be the world's largest outdoor compact antenna range, designed and built by GTRI, at the U.S. Army's Electronic Proving Grounds, Fort Huachuca, Arizona

Download>

GTRI built the world's largest outdoor compact radar range for the U.S. Army in 1989 at Fort Huachuca, Arizona. The facility was designed to measure antenna performance from six to 40 GHz on vehicles and helicopters. It includes a 75-foot parabolic reflector and a lift capable of positioning objects up to 50 feet long and weighing as much as 70 tons.

An antenna's performance varies across different frequencies. It is dependent on its location, as well as the shape of the object upon which it is mounted. In the late 1960s, to determine the best antenna location for a particular situation, Richard C. Johnson invented the compact radar range.

The technique simulates a plane wave over the entire antenna undergoing testing. It involves two main elements: a parabolic reflector and a mechanical device that lifts and rotates the target antenna.

Amy Jacoby places an experimental antenna onto a positioner for testing in GTRI's Compact Range

Download>

Although the compact range operates in a relatively small space (most are indoors) it can measure the radiation patterns of antennas as they would occur over long distances. Other advantages of indoor compact ranges are security and the ability to operate regardless of weather conditions.

The alternative to a compact range is a far field range test site, consisting of two towers whose distance apart depends on the target size and frequencies studied. One tower holds the antenna under test while the other receives the signals. Under many circumstances, given the size of vehicles and the high frequencies involved, far field towers would have to be stationed several miles apart.

A typical compact radar range provides a useful measurement area approximating a four foot cylindrical region large enough for a four foot reflector, although actual useful area varies with frequency band and accuracy required. Antennas up to eight feet can be handled by the compact range, which includes a dedicated air-handling system for temperature stability.

Visit our Electromagnetic Test and Evaluation Facility Web site