Frequency and Polarization Reconfigurable Slotted Microstrip Antenna

In this paper, a PIN diode radio frequency (RF) switch integrated frequency and polarization reconfigurable antenna is reported. Three pin diodes are used to change the current path length and to modify the surface current distributions, resulting in frequency as well as polarization diversity. When all switches are in the ON state (mode-1), the antenna operates in 2.42 GHz band with linear polarization and when the switches are OFF (mode-2), the antenna resonates at 2.13 GHz with circular polarization. The desired results are obtained using a surface modification of the patch which is achieved by rigorous optimization in Ansys Electromagnetic Suite. In the mode-1, the antenna has an axial ratio of above 10.68 dB, which indicates linear polarization and, in the mode-2, the antenna has an axial ratio of 0.78 dB which ensures circular polarization. To validate the simulated results, the prototype of the antenna is fabricated and measured results are compared.