Abstract: A micro-strip fed triangular ring slot antenna with a fundamental mode at 5.5 GHz . to suppress the additional harmonics mode exited by the triangular ring slot , a single inverted U-shaped slot(defected ground structure) is integrated into the triangular ring slot . through this , harmonic suppression over a wide band width 11 and 16 GHz.

Keywords: Defected ground structure, harmonic suppression , micro-strip fed, ring slot antenna.