This article introduces a conventional patch antenna with defected ground plane structure to operate under 3.4 and 4.6 GHz frequencies suitable for wireless terminal devices in WiMAX and extended C band applications. The antenna is designed on a 20 × 20 × 1.6 mm3 FR-4 substrate. A 7x4 array of Triangular shaped interconnected Closed Loop Structures (TCLS) are etched on the ground plane which behaves as a metamaterial in the 4.5GHz frequency range. This property of metamaterial contributes in creating a narrow band response along with the patch antenna resonance. Over the entire operating region, an omnidirectional and bidirectional radiation pattern are observed in the orthogonal planes. © 2019 IEEE.