Design of compact microstrip-fed triple-band slot antenna with defected ground structure for wireless communications

Abstract

This article presents the design of a compact microstrip-fed triple-band slot antenna for WLAN/WiMAX/C-band downlink satellite communications. The newly designed proposed simple structure has a considerably high-center frequency ratio and can significantly suppress cross-polarization levels. This antenna consists of a double annular-ring slot (DARS), two L- and one I-shaped slot on the radiator, and an ellipse-shaped-slit (ESS) based defective ground structure (DGS) is imposed. Furthermore, to achieve a better impedance bandwidth and impedance matching, an insert-fed has been implemented on the proposed structure. The proposed antenna has the advantages of the easy tuned of individual resonant frequency and relatively simple antenna structure. The fabricated prototype resonates at 11.13% (2.257–2.523 GHz), 5.63% (3.455–3.655 GHz) and 6.05% (4.012–4.262 GHz) and gives a gain of 4.05, 2.52 and 2.15 dBi, respectively, and cross-polarization nearly −38.85 dB. The transmission line model of the proposed antenna is presented, and it shows the antenna behavior based on the effect of each element. It is observed that the characteristics of the RLC circuit model result is close to the simulated results using the CST simulator.