Antenna (IMAGE) Southwest Research Institute Caption SwRI's AF-369 VHF/UHF Terrestrial Direction-Finding Antenna provides accurate direction finding of radio frequency transmissions from 20 MHz to 3 GHz. It was recognized by R&D Magazine as one of the most important innovations of 2019. Credit Southwest Research Institute Usage Restrictions For informational and educational purposes only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.