A Dipole Excited Ultrawideband Dielectric Rod Antenna With Reflector

摘要

A novel very compact ultrawideband dielectric rod antenna with metallic reflector is presented. The desired ${{rm HE}}_{11}$ mode on the rod is excited by a biconical dipole fed by a broadband tapered microstrip line balun. The input reflection remains below ${-} {hbox{10 dB}}$ from 3 up to 20 GHz. The antenna exhibits a flat gain larger than 7 dBi over the whole ultrawideband frequency range from 3 to 10 GHz approved by the Federal Communication Commission. An almost constant transient performance over a wide azimuth angle of ${pm}$40 $^{circ}$ is obtained with small dispersion.