By Kelly Hill

AT&T is using a drone carrying a lightweight signal generator to test high-gain outdoor antennas in spectrum up to 40 GHz.

As described in AT&T’s filings with the Federal Communications Commission, the carrier seeks to measure the radiated patterns of high-gain antennas in order to qualify them for point-to-point links and to test sidelobe suppression techniques.

“Correctly measuring the radiation pattern of a high-gain antenna can be challenging as it must be done in the antenna’s far field, often at 100 meters or more,” AT&T said in its filing, adding that traditional outdoor testing can run into issues such as ground and structural reflections, while tower-based experiments add logistics and personnel safety issues. AT&T said that it wanted to use a drone because it would be a “faster, easier and safer way to make such measurements.”

The carrier’s experiments at its Middletown, New Jersey campus include a GPS-equipped drone that will carry both a signal generator and a downward-facing, tapered slot or horn antenna for transmission, from a maximum height of 120 meters above the ground, with the antenna-under-test on the ground and connected to a receiver.

AT&T was granted a two-year special temporary authority, through April of 2024, to conduct that testing, using seven different frequency ranges between 6 GHz and 40 GHz for the intermittent experiments.