The FCC Opened a Notice of Proposed Rule Making on Directional Antenna Performance Verification under MB Docket No. 21-422. The Joint Petition for Rule Making was filed by Dielectric, LLC; Educational Media Foundation; Jampro Antennas, Inc.; Radio Frequency Systems; and Shively Labs. See Fact Sheet and Public Notice links below.
Directional antennas radiate more energy in some directions than in others, in order to prevent interference to other stations or to keep the signal from radiating outside the station’s authorized service area. FM radio is the only broadcast service that requires stations using directional antennas, when applying for license, to provide physical measurements to verify the directional pattern. To provide the required physical measurements, stations must either build a full-size mockup of the antenna and supporting structures to measure the pattern generated or must build a scale model of the antenna and structures for measurement in a laboratory. Both approaches increase costs, are time consuming, and raise a number of difficulties such as accurately replicating the installed antenna environment. Four manufacturers of FM broadcast radio antennas and one licensee of FM broadcast stations (Joint Petitioners) seek an amendment to our rules to allow applicants proposing directional FM antennas the option of verifying the directional antenna pattern through computer modeling, rather than by physical measurements as is required by the current rules.