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/λd ranging from 0. 001 to 0. https://www.marcelovicente.com/product-category/volume-gel/