An asymmetric coplanar strip-fed 7-shaped monopole antenna for miniaturized communication systems

Abstract

A compact asymmetric coplanar strip (ACS)-fed monopole antenna for miniaturized communication systems is proposed. It consists of an ACS-fed 7-shaped monopole, a partial ground plane, and an FR4 substrate. The proposed antenna occupies a very compact size of only 30 × 13 mm2 which accords with the development trend toward miniaturized electronic components. The 7-shaped monopole can be considered as a combination of three parts—a rectangular strip on the top, a trapezoidal strip in the center, and a straight microstrip feed line at the bottom—which generates two separate resonant frequency bands. By introducing an open-ended T-shaped slot in the rectangular strip, a new resonant mode can be excited. Detailed descriptions of the design evolution as well as the parametric study are given to better understand the mechanisms of the proposed antenna. Experimental results demonstrate that it can provide a triple-band frequency range compatible with the 2.4/5.2/5.8 GHz WLAN (2.4–2.485, 5.15–5.35, and 5.725–5.825 GHz) and 3.5/5.5 GHz WiMAX (3.4–3.7 and 5.25–5.85 GHz) operating bands. Furthermore, stable radiation patterns with satisfactory gains make it a good candidate as an internal antenna for compact multiband communication systems. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1566–1572, 2016