One of the Quietest Places on Earth

By Adam Stone

The world is becoming increasingly cluttered by radio frequencies from wireless devices, making testing radars a challenge. To ensure radars are going to perform as needed, engineers need a space that eliminates radio interference.

Such places, called anechoic chambers, exist. But none were quite right to test Northrop Grumman’s ultra-sophisticated APN-241 radar. So, we built our own.

Our Warner Robins, Georgia, facility is now home to a specialized anechoic chamber that adds the capability to perform near and far-field antenna testing that previously had to be outsourced.

Why the Silent Treatment?

"An anechoic chamber is essentially a large room with echo-absorbing material inside it," said Jon Teregeyo, Northrop Grumman’s principal project manager on the program. "You can transmit and receive radar signals inside this room with no interference, which allows us to do some very fine, detailed testing on these radar systems."

This matters because when it comes to radio frequency (RF), the air around us has become very noisy. "You've got cell phones, Wi-Fi — all these signals that can interfere with a radio test," said Joel Conrad, chief engineer and lead technical expert on the program. "You need that very quiet radio space to ensure your test results aren't impacted by all those external environmental factors."

A Unique Solution

The new chamber is specially configured to support both compact and far-field testing, something few other testing chambers can achieve. Achieving that cost-effective, dual-use outcome required considerable engineering expertise.

It takes a specialized skill set not just to devise such a system but to ensure its smooth operation. "There's a lot of technical proficiency that's required to perform both near- and far-field tests," Teregeyo said.

Northrop Grumman's new chamber is distinctly suited to meet another key need for the military. As a classified facility, it will make onboarding the new radars significantly faster and most cost-effective.

"Prior to this, some limited testing could be done in Atlanta, but that process was both time-consuming and labor-intensive," said Thurman "T.R." Burke, manager of product support engineering. "They had to travel from Warner Robins to one of the suburbs of Atlanta. For every radar, they had to carry it up there, set it up there, run the test and then bring it back down here. There's a lot of cost involved with that — and a lot of time."

With the long- and short-range tests now housed together in a secure, classified facility, customers will trim that expense and be more readily able to field the new, repaired, or upgraded equipment.