Antenna pattern effects in normalized site attenuation

Abstract

In the ANSI C63.4 development of normalized site attenuation (NSA) for vertical polarization the E-field sine pattern generated by short dipoles was used to account for the additional attenuation that occurs as a function of the antenna patterns. A pattern dependent NSA equation is developed incorporating antenna pattern factors for any types of antennas for which mathematical expressions of the patterns exist. For resonant dipoles, biconicals and log-periodics the decibel differences from the existing standard have been found to be small, leading to increased confidence in the utility of the present standard.