A Novel Dipole Antenna Design With an Over 100% Operational Bandwidth

A novel design of a dipole antenna with ultrawideband characteristics is presented, which uses an additional shorter dipole as a matching element whose imaginary part (or susceptance) of input admittance compensates for that of the principal dipole in the frequency band of operation. Since both dipole elements efficiently radiate energy, the proposed twin-dipole antenna exhibits a higher efficiency compared to a conventional design. The measurement results have revealed that the twin-dipole is able to achieve a bandwidth of 131% (S11 <; -10 dB) from 1.6 GHz up to 7.7 GHz, with good radiation performance and more than 75% radiation efficiency.