Scan Impedance for An Infinite Dipole Array: Hansen´s Formulas Compared with Ansoft HFSS Simulations [EM Programmer´s Notebook]

The present study reviews some results for the well-known case of an infinite array of center-fed strip dipoles above a ground plane. No dielectric sheet is considered. In particular, we are interested in the test of simple equations for the scan (or active) impedance given by R. C. Hansen in his monograph [1, pp. 236-238]. The analytical method used in this study is the canonical Floquet expansion approach. It leads us to the results obtained by Oliner and Malech [2] and Stark [3], and allows us to establish the domain of validity for Hansen´s formulas. Simultaneously, we compared the analytical data with Ansoft HFSS simulations, which use the periodic boundary conditions for a vertical unit cell. It was found that the agreement was acceptable for the E-plane scan, but the results may be significantly different for other scan planes.