Complex fit normalized site attenuation for antennas with complex radiation patterns

Complex fit normalized site attenuation (CFNSA) is proposed as an improvement over the theoretical model in ANSI C63.5. CFNSA accounts for phase center and antenna pattern variations for complex antennas, such as log periodic dipole arrays (LPDA) by solving for the pattern and phase center parameters using S₂₁ at multiple heights. A recent study has shown that a simple antenna pattern such as cosⁿθ is insufficient to represent that of an LPDA above 500 MHz. This paper studies the feasibility of using a higher order analytical function to characterize the complex patterns of a LPDA. It investigates pattern formulations, which result in realistic antenna patterns with small number of unknowns.