An improved formula for the resonant frequencies of the triangular microstrip patch antenna

An improved version of a formula due to J.S. Dahele and K.F. Lee (ibid., vol.AP-35, p.100-101, Jan. 1987) is presented for predicting the resonant frequency of a triangular microstrip patch antenna. Using a different effective length and the actual substrate permittivity, the technique previously used for the case of a circular disk is modified to produce greater accuracy than previously reported in the literature. This method consistently predicts resonant frequencies more accurately through the first five resonances.>