Directive electric-magnetic antenna for ultra-wideband applications

A novel planar non-dispersive antenna for ultra-wideband radar applications is introduced. The antenna concept is based on the combination of the electromagnetic characteristics of a loop and a planar monopole. A detail discussion on the proposed antenna topology and architecture is presented, and a dedicated backfeeding technique that shows a low transmission loss over a very wide frequency band is suggested. A frequency-independent equivalent circuit of the proposed antenna, useful in the codesign and optimisation of the relevant radio frequency front end is also extracted. It is experimentally demonstrated that the considered radiating element features a fractional bandwidth of 67%, good impedance matching, reasonably constant group delay and uni-directional stable over frequency radiation patterns with front-to-back isolation of about 12 dB.