Optically Controlled Superwideband to Multiband Reconfigurable Antenna for Wireless Applications

Aim: Design of a reconfigurable microstrip planar antenna for wireless applications. Objective: To design an optically controlled microstrip planar antenna with superwideband (SWB) to multiband reconfigurable characteristics without using any biasing network. Methods: The use of a photoconductive switch made of Cadmium Sulphide (CDS) based semiconductor is conceived to realize the optically controlled reconfigurable antenna. The operating characteristics of the proposed antenna have been changed between SWB to multiband when the CDS coating is illuminated by the light-emitting diode. Results: Under the switch-off condition, SWB of 167% (1.8-20 GHz), fractional bandwidth with higher Bandwidth to Dimension Ratio (BDR) and a bandwidth ratio of 11.11:1 are achieved. While for the switch-on condition, triple-band (1.8-3.9 GHz, 4.3-7.3 GHz, and 8.2-15.4 GHz) operation with the resonating frequency of 3.4GHz, and 5.5GHz and, 12GHz covering the useful WiMAX, and WLAN wireless bands have been achieved with the realized peak gain of 2.34dBi, 4.18dBi, and 3.08dBi, respectively. Conclusion: An optically switchable SWB to triple-band compact planar monopole antenna has been analyzed and presented based on the simulation results. This design is reasonably compact and provides better BDR than the reported antennas of its class. The proposed design is flexible enough to adjust the operating bands by varying the dimensions of the defected ground structure (DGS) and stub. This antenna with switching ability can fulfill the requirement of the antenna society for wireless applications.