Wideband antenna with a folded dipole and a folded shorted patch

Abstract

A new wideband antenna composed of a folded dipole and a vertically folded shorted patch is presented in this paper. Employing a folding technique, the height of the antenna could be reduced from 0.25lambda to 0.15lambda. The antenna is excited by a Gamma-shaped strip, consisting of an air microstrip line and an L-shaped coupled strip line. With the presence of the coupled line, the antenna yields a wide impedance bandwidth of 48.4% (SWRles2) from 2.249 to 3.687 GHz. Moreover, through the combination of two radiating elements (i.e. the planar dipole and the shorted patch), the antenna finds a stable broadside radiation pattern across the entire operating bandwidth with low cross-polarization and low back radiation. The proposed antenna has a maximum antenna gain of approximately 6 dBi.