A Multi-Band Asymmetric Stepped-Slot Antenna for DCS, PCS, WiMAX, 4G, and WLAN Applications

Abstract- A multi-band stepped-slot antenna, fed by modified 50 Ω coplanar waveguide (CPW) transmission line is described and implemented. The designed antenna effectively supports digital communication systems (DCS 1.71-1.88GHz), personal communication systems (PCS 1.85-1.99 GHz), worldwide interoperability for microwave access (WiMAX 3.30-3.80GHz), fourth generation (4G 3.40-4.2 GHz) mobile communication system, and wireless local area network (WLAN 5.15-5.35 GHz). In order to cover the aforementioned valuable bands, in the first step rectangular slots are subtracted symmetrically from the radiating patch. Besides, stair-shaped rectangular slots are etched at the radiator edges. Also, to operate at DCS and PCS systems, dual-section CPW feed line with different widths is designed. Actually antenna is designed by using quasi-fractal methods, to cover frequency ranges of 1.64-1.99 GHz, 3.35-4.3 GHz and 4.8-5.4 GHz (for |S11|< -10 dB). The antenna size is 75.2 × 38.54 × 1.6 mm3 and it is etched on FR4 substrate. The antenna development steps are presented and discussed in detail. Moreover investigation of important design parameters is performed. The designed multi-band antenna has respectable results such high gain in center of each operating band and considerable efficiency of 90%, 85% and 86% in 1.85, 4 and 5GHz respectively. Also omni-directional patterns and acceptable group delay are obtained. Measurement data are presented to validate the numerical outcomes. All of these prominent features make this antenna, worthwhile for multi-band applications.