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

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.