Novel miniature extremely-wide-band antenna with stable radiation pattern for spectrum sensing applications

A planar extremely-wide-band antenna is designed and simulated. Measurements are presented. The proposed antenna is a printed elliptical slotted monopole with a triangular ground plane, fed by a semi-ring trident arm followed by a tapered CPW line. The frequencies covered for a VSWR $ \leq 2$ extend from 0.67 GHz to 12 GHz with stable radiation patterns to ensure minimal pulse distortion. This is guaranteed by multimodal analysis of the radiating current on the radiator using the theory of characteristic modes. Numerical and experimental results are in good agreement. This novel miniaturized antenna ( $0.15 \times 0.07{\lambda _l}$ , where ${\lambda _l}$ corresponds to the wavelength of the lowest matched frequency) is a good candidate for wide-band spectrum sensing in the TV white space band in the context of cognitive radio applications.