An analysis of the complex fit normalized site attenuation method

The complex fit normalized site attenuation (CFNSA) method was introduced in 2000 as an enhancement to the normalized site attenuation (NSA) model used in ANSI C63.4 and C63.5. The simple dipole NSA model is insufficient to predict the behavior of complex antennas like log periodic dipole arrays (LPDAs) and horns. Thus, NSA measurements made with these antennas using free-space antenna factors can have significant deviations from that predicted by the model. The CFNSA model is a modification to the simple dipole NSA model to account for the variations in antenna pattern and phase center that are possible in complex antennas. This paper evaluates the effectiveness of the phase center/pattern matching (PCPM) method previously proposed, as well as the use of directly measured pattern and phase center information, for a variety of antenna types.