Multi-Port Network Approach for the Analysis of Dual Band Fractal Microstrip Antennas

Abstract—The multiport network approach is extended to ana-lyze the behavior of microstrip fractal antennas. The capacitively fedmicrostrip square ring antenna has the side opposite to the feed arm replaced with a fractal Minkowski geometry. Dual frequency operation is achieved by suitably choosing the indentation of this fractal geometry. The width of the two sides adjacent to this is in-creased to further control the resonant characteristics and the ratio of the two resonance frequencies of this antenna. The impedance matrix for the multiport network model of this antenna is simpli-fied exploiting self-similarity of the geometrywith greater accuracy and reduced analysis time. Experimentally validated results con-firm utility of the approach in analyzing the input characteristics of similar multi-frequency fractal microstrip antennas with other fractal geometries. Index Terms—Fractal shaped antenna, microstrip ring antenna, multi-port network model. I