UA researcher designing Xtremis test site, chamber

Technology startup Xtremis, in collaboration with the University of Arkansas, is designing and planning to construct a high-tech campus in southern Washington County to test wireless communications equipment.

Samir El-Ghazaly, Distinguished Professor of electrical engineering at the UA, is designing the campus’ components, including an anechoic chamber, an open-air electromagnetic test site and a calibration test bench for software-defined radios. The work is being carried out with a nearly $770,000 subcontract from Xtremis.

“Samir is one of the premier RF researchers in the country,” said Xtremis CEO Jay Harrison. “The partnership with the university and Samir is one of the key factors that drew the entire company to the area.”

El-Ghazaly started on the design work last summer and plans to complete it this summer. He’s among a team of seven, comprising consultants and doctorate and post-doctorate students, working on this. Groundbreaking for the anechoic chamber is set for 2026.

“When completed, this project will have the potential to attract companies interested in RF testing to Northwest Arkansas and increase our ability to have startups and to have significant economic impact on the area,” he said.

According to a news release, the chamber will simulate infinite space, where electromagnetic waves can travel unimpeded and not echo. He said the chamber’s dimensions are still being determined, but it’s planned to be up to 40 feet long, 40 feet wide and 40 feet tall. He likened it to a box built inside of a larger building. There’s a smaller version of such a chamber in his lab at the UA.

He said the new chamber could test antennas with radio frequencies from about 20 gigahertz to as low as 300 megahertz, much lower than his lab can test. Lower-frequency electromagnetic waves can travel longer distances.

El-Ghazaly said few universities have large anechoic chambers because of their size and cost. These chambers can cost $1 million to $2 million depending on their size. He noted that the chamber at his lab was built about 15 years ago for about $250,000.

According to the release, once the anechoic chamber is built, other companies can test antennas or certify the RF interference produced by large electrical devices, such as cars or airplanes. The testing facilities might attract other startups to Northwest Arkansas.

“Xtremis is interested in collaborations with universities and other commercial entities,” Harrison said. “We see this infrastructure as being a draw for other high-tech businesses to partner with us.”

El-Ghazaly said the open-air electromagnetic test site will be outside the chamber building and allow for tests across a broad frequency range. The site will enable radio tests in real conditions in a remote location with little surrounding electromagnetic interference.

Also planned for the campus is the calibration test bench for software-defined radios, which he said have characteristics that can change dynamically. For example, smartphones change frequencies depending on their proximity to a tower.

Xtremis started working with the UA in 2023 to research improved antenna designs for spectrum monitoring and redevelop the site of the former Southwest Experimental Fast Oxide Reactor (SEFOR) into a first-of-its-kind advanced spectrum technology campus. Xtremis was spun out of Vanderbilt University in 2021 to commercialize research that allows radios to share spectrum and avoid interference.

It has opened a testing facility in Northwest Arkansas that will have 200 employees within five years. The five-year plan also included attracting 1,250 indirect, high-tech jobs to the area.

The company recently received U.S. Army contracts valued at more than $80 million to implement Xtremis’ artificial intelligence (AI) algorithms to improve troops’ situational awareness and management of the electromagnetic spectrum.

The Devil’s Den Proving Ground in southern Washington County comprises an open-air laboratory to develop technologies to improve the performance and resilience of wireless devices and communications. Fayetteville-based Marlon Blackwell Architects is the designer.

Harrison previously said the focus will be to develop technology to allow radios to operate “with higher performance in congested environments.” The technology will enable more radio transmitters to operate “simultaneously without interfering with one another.”

The Devil’s Den Proving Ground was projected to cost between $15 million and $20 million to build. Renovation of the existing structure and land work at the site are set to start in June.