Compact Ultrawideband Antenna on Folded Ground Plane

A compact ultrawideband antenna on folded ground plane is proposed, which is a compact and low-profile structure. The proposed antenna mimics the operation of a unit element of the tightly coupled dipole array (TCDA) with modified boundary condition. The antenna does not have the PMC boundary required by the original TCDA, which makes the implementation and the impedance matching of the proposed antenna easy. All the design procedures are explained and confirmed by the EM simulation. The measured results show that the impedance bandwidth (IBW) is 0.72-3.43 GHz (130.6%) for the VSWR <; 2 and that the radiation efficiency is over 89% in the operating band. The average peak gain is 2.33 dBi. These results are in good agreement with those of the simulation. The proposed antenna is compact, with an electrical size (κα) of 0.82 at the lowest operating frequency and an overall dimension of 0.17λ
_low
× 0.17λ
_low
× 0.11λ
_low
in terms of the wavelength at the lowest operating wavelength.