Comparison of Different Order Filtering Antennas

Design, simulation, comparison, and analysis of filtering antennas is presented. Three filtering microstrip antennas, of different orders, are presented. The proposed antennas are designed to operate as a third, fourth, and fifth order band-pass filters (BPF). The antennas are designed to operate in the ISM band of 2.4 GHz with bandwidths of 62 MHz, 68 MHz, and 71 MHz respectively. Each antenna is composed of a microstrip feed line, open-loop resonators, and a microstrip patch of a rectangular shape. The proposed antennas were simulated using two different numerical techniques including Finite Different Time Domain (FDTD) and Method of Moment (MOM). From the simulated results, it is observed that the antennas preserve the microstrip antenna characteristics within the passband while providing an extra out-of band gain suppression due to the embedding filtering characteristics. As expected, the selectivity of the gain response improves as the order of the filtering antenna is increased.