Regulating and standardizing directive antenna patterns to improve coexistence

The antenna limits imposed in America and Europe are compared with the patterns in an ITU-R Recommendation. As most of RF interference emanates from the sidelobes of the transmitting antennas and enters through those of the receiving antennas, the regulation and standardization of antenna patterns is essential to optimize RF spectrum reuse. Since there are no regional standards in Asia and Africa for directional point-to-point antennas, the reference envelopes defined by the ITU, the European-based ETSI and the USA-based FCC are adopted globally. Depicting these limits, next to measured antenna patterns from two different suppliers, reveals that the ETSI limits are more restrictive than those of the FCC. New theoretical evidence is provided for the 2018 revision of the ITU Recommendation. Proposals are provided to tighten FCC limits and to loosen those of ETSI.