Optimizing frequency reconfigurable antennas using fuzzy interface system with efficient gains and reflection coefficients in all modes

Abstract

In this paper, a teaching‐learning‐based optimization is applied to determine slot shape in the ground plane and PIN diode/diodes location/locations into slot simultaneously to design frequency reconfigurable antennas. A fuzzified cost function is used to ensure the efficient performance of the antenna (efficient reflection coefficients and gains) in all modes. Furthermore, two constraints are added to the optimization problem for solving complications of finding the shape of slots and diode/diodes location/locations in slots by the direct link of MATLAB‐HFSS. The first proposed design includes one diode which can operate in the bands with center frequencies 5.3 and 5.62 GHz in OFF/ON modes with 5 dBi/4.8 dBi gains, respectively. In the second design, an antenna is presented with two diodes which can operate in four bands with center frequencies 4.66, 4.92, 5.54, and 5.61 GHz in the OFF–OFF, OFF–ON, ON–OFF, and ON–ON modes with 3.5, 3.9, 4.9, and 5 dBi gains, respectively. The proposed antenna with four modes of operation is fabricated, and the comparison of the simulated and measured results shows a good agreement.