Modified Wolff model for resonance frequency of covered rectangular microstrip patch antenna

A modified Wolff model is proposed to calculate the resonance frequency of a covered microstrip rectangular patch with the accuracy of spectral domain analysis. In most of the cases the calculated frequency is within 0.6% of the measured value. The modified Wolff model can be used for multi-layered substrate and multilayered cover. The original Wolff model determines the resonance frequency of the uncovered microstrip patch.