Improved Estimation of the Third-Order Harmonic Emissions of Land Mobile Radio Base Stations

Abstract: NTIA/ITS has developed an improved electromagnetic compatibility (EMC) analysis method that can be applied to more accurately model real scenarios for evaluating interference. The methodology described in this report can be used to conduct EMC analyses for base stations that use a variety of antennas. The model can be used to determine the received power in the proximity of the base station at both the fundamental and harmonic frequencies. It uses accurate radio-wave propagation models and antenna models. The antenna models can be created for the fundamental and third harmonic frequencies of many antennas. Fields adjacent to the base station antenna are heavily influenced by interactions with ground, and the electromagnetic fields are dominated by the side lobe structure of the elevation pattern of the base station antenna. The described rigorous EMC analysis for a base station considers all of these factors to assess interference more accurately than previous methods.

Keywords: undisturbed field method; electromagnetic compatibility; numerical electromagnetics code; land mobile radio; third order harmonics; received power; global positioning system; folded-dipole antenna

The full report is available at http://www.its.bldrdoc.gov/publications/2555.aspx