An Accurate Edge Extension Formula for Calculating Resonant Frequency of Electrically Thin and Thick Rectangular Patch Antennas With and Without Air Gaps

A new and accurate edge extension formula based on the Taguchi method is proposed to calculate the resonant frequency of electrically thin and thick rectangular patch antennas with an air gap (RPAAG) and rectangular patch antennas without an air gap. Based on 3205 antennas data random distribution in the electrical substrate thickness h/λ
_d
ranging from 0.001 to 0.2 and the dielectric constant ranging from 1.0 to 10.2, the edge extension formula is created with the Taguchi method. The resonant frequencies predicted using the proposed formula are in better agreement with simulated and measured results than those calculated with the existing formulas in other literatures, especially for electrically thick substrates. Furthermore, experimental results for the RPAAG are given, which shows that h/λ
_d
should be less than 0.13 in the design of a capacitively fed RPAAG.