Extremely small monopole antenna for wideband applications

A planar, extremely small wideband monopole antenna is proposed. The proposed antenna consists of a rectangular radiating patch with a star‐shaped slot and a plus‐shaped conductor‐backed plane, which provides a wide usable fractional bandwidth of 122% (5.25–21.61 GHz). Using a plus‐shaped conductor‐backed plane, band‐notched characteristics with notch frequency band at 6.95–8.22 GHz is obtained. The designed antenna is compact and of small size (10 × 13 × 1.6 mm 3 ) with a 50 Ω feed line and offers a very simple geometry suitable for low cost fabrication and straightforward printed circuit board integration. Measured and simulated reflection coefficient curves are provided. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:617–621, 2015