A planar extremely-wide-band antenna is designed and simulated. The proposed antenna is a printed elliptical slotted monopole antenna with a triangular ground plane, fed by semi-ring triple feed followed by a tapered CPW line. The frequencies covered for a VSWR ≤ 2 extends from 0.65 GHz to 12 GHz with stable radiation patterns to guarantee minimal pulse distortion. This configuration has been achieved by analyzing the currents on the antenna by means the characteristic mode theory. Both numerical and experimental results are presented. This miniaturized antenna (largest dimensions of the order of 0.14 λ) is a good candidate for wide band spectrum sensing in the context of cognitive radio applications.
