In this article, a new design for the open slot antenna with a high front‐to‐back gain ratio is proposed and presented. By utilizing a two‐element array topology, a power combination is achieved and a unidirectional radiation pattern is derived. To suppress the backward radiating power, a pair of symmetrical notched slits with uniform width is etched such that the currents distributing along two longitudinal edges of the ground plane cannot flow backward. In addition, three arrays of eight‐element metal strips are utilized as a power director to increase the forward power and improve the front‐to‐back ratio of the antenna. From the measured results, the proposed antenna topology demonstrates a front‐to‐back (F/B) ratio of 22.3 dB and possesses superior end‐fire radiating characteristics. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1273–1277, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26782