FCC to Update Rules to Allow Digital Generation and Verification of Antenna Directional Patterns

The FCC has released a draft Report and Order to amend its broadcast radio rules to allow the use of computer models to verify antenna directional patterns. Barring unexpected developments, the Report and Order will be adopted during the Commission's May 19th open meeting

This proposed rule changes are great news for applicants - under the prior rules, applicants were required to submit tabulation of plot and measured relative field patterns of a directional antenna by building a mockup or scale model of the antenna and supporting structures. Instead of building these structures, applicants will now be able to use computer models-substantially decreasing the cost and time of pattern verification.

The great majority of commenters favored computer modeling, noting positive results on the accuracy of computer modeling. Although engineering firms will not be able to charge as much for directional antenna verification, several firms did support this proposal.

This rule change brings FM and LPFM stations into conformity with AM and DTV station licensing, which already allow for computer modeling to verify directional antenna performance. However, an important distinction from the AM and DTV rules are that FM and LPFM computer models must be performed by the antenna manufacturers. That limitation does not apply to AM and DTV applicants. The Commission did not set requirements for what software products must be used in this modeling, only that commercially available software be identified and custom software include a description of the software and methods sufficient for potential replication.

The Commission emphasizes that these rule changes will provide for more accurate proofs of performance and decrease the time and costs of verification for applicants. As you prepare to file license applications for FM and LPFM antennas, contact your FHH Law attorney for the most up-to-date requirements.