In this paper, a new step by step method is introduced to design a novel circular shaped microstrip patch antenna. The calculations are based on transmission line model. The feeding uses a uniplanar corner-fed patch antenna presented with single-point microstrip. This work presents a new model for design of circular microstrip antenna (MSA). In this model, a closed form expression is used for accurate determination of the resonant frequency of circular microstrip patch antenna. The calculated resonant frequency results are in good agreement with the simulated results reported elsewhere. We present the simulations results of two types of circular patch antenna in K-band. The conception of this patch antenna is realized by software HFSS