Design of Multiband Frequency Reconfigurable Antenna with Defected Ground Structure for Wireless Applications

A novel printed rectangular shape, multi-band frequency reconfigurable antenna with defected ground structure (FRDGS) for multi standard wireless communication systems is designed in this article. The ground plane is modified by embedding U shaped slots with open ends and I shaped slot in short ends to realize the multi band frequency of the antenna and to improve the parameters of the antenna design. The two U shape slots are etched symmetrical to each other to reduce the cross polarization of the antenna. The DGS in the ground plane altered the modeling characteristics of transmission lines with the equivalent values of inductance, capacitance and resistance. Three PIN diodes are inserted in the ground plane to acquire the switching characteristics of multi-resonance frequency. Simulated and measured output clearly depict that the antenna proposed is efficient to change between twelve dissimilar resonant frequency bands centered at 1.36, 1.8, 3.0, 3.9, 5.0, 6.2, 6.4, 7.4, 7.9, 8.2, 8.4, 8.6 GHz through different states of modes over the frequency spectrum from 1.33 to 8.7 GHz. The parameters such as reflection coefficient, VSWR, 2D and 3D radiation pattern, bandwidth, peak gain, peak directivity, gain and directivity are simulated using Ansoft HFSS 17.0v. The proposed antenna finds application in various wireless communication system such as Wi-Fi (5 GHz), WLAN (5 GHz), WI-MAX, UWB (3.1-10.6 GHz) system, fixed mobile and satellite communication systems.