A broadband open-sleeve dipole antenna mounted above a tunable EBG AMC ground plane

A broadband open-sleeve dipole antenna is mounted above a tunable electromagnetic bandgap (EBG) surface resulting in a low-profile narrowband antenna system that is tunable over an octave bandwidth. The EBG surface is composed of an array of square metallic patches connected via tunable capacitors over a thin PEC backed dielectric substrate. The capacitors tune the resonance of the surface down in frequency resulting in a low-profile antenna system that can be tuned from 1.2 GHz to 2.3 GHz with a relative thickness of only /spl lambda//30 to /spl lambda//15 at the lower and upper frequency limits respectively.