Application of the Total Dynamic Capacitance of Circular Microstrip Disk for Calculating the Resonant Frequency of Some Microstrip Antennas

Abstract

Simple and accurate analytical formula of the total dynamic capacitance of a circular microstrip disk to account for the effect of extended disk due to the influence of the fringing fields at the edge of a circular disk is used for determining the formulae of the dynamic permittivity and the effective dimension. Both formulae are simple and accurate for calculating the resonant frequency of circular, rectangular, equilateral triangular and elliptical disk microstrip antennas. The calculation of the resonant frequency as the function of the dynamic permittivity and of the effective dimension can be done rapidly and the obtained results are in good agreement with the available measured data.