A back-to-back planar folded dipole on EBG substrate

A planar antenna composing two back-to-back folded dipoles printed on a dielectric substrate is presented and the performances are investigated when it is mounted on a mushroom-like EBG substrate. A wide impedance bandwidth is achieved of 4.95-6.95 GHz for the constructed prototype, about 33.6% of the central frequency. Within the operation band, stable gain and radiation patterns are obtained, and the back radiation is less than -27 dB. Whether in E plane or in H plane, the cross polarization is small enough to be negligible.