A model for the radiation modes associated with capacitor-loaded circular patch antenna

In previous studies, a new type of patch antenna was found. This new type of patch antenna is a modification of the traditional patch antenna loaded with capacitors. The operating frequency of this type of patch antenna can be controlled through varying the position and value of loaded capacitors in the microstrip antenna. The variation of the radiation modes can be treated as a change in the effective patch size due to the loaded capacitors. A resonant model can be used to explain the behavior of this type of patch antenna. In this paper, a formula to predict the radiation modes of a circular patch antenna with radii of 15 mm, 20 mm and 25 mm is shown. In this case, the operating frequency of the patch antenna with loaded capacitors can be operated at as low as 1/3 of the original frequency.