A new kind of ultra wideband antenna,which consists of a leaf-like dipole and a dielectric block,is proposed and analyzed.The dielectric block is attached in parallel with the dipole near its feed point.Thus,the near field is attracted to the side where the dielectric block is located.It leads to a focusing effect of the energy in the far zone.The finite-difference time-domain(FDTD)method combined with the perfectly matched layers(PML)technique is used in the simulation of the antenna radiation characteristics.The research shows that,with proper dielectric loading and 50 Ω feeding line,the bandwidth of the antenna can be up to 6.5 GHz,from 3.5 GHz to 10 GHz with VSWR(voltage standing wave ratio)less than 2.5.
