Suppression of Cable Leakage Current for Edge-Fed Printed Dipole UWB Antennas Using Leakage-Blocking Slots

A simple method is presented for suppressing cable leakage current for printed dipole ultrawideband (UWB) antennas using thin leakage-blocking slots. Their effects on VSWR and pattern characteristics are demonstrated by comparing the performances of two identical coplanar waveguide (CPW)-fed printed dipoles except for the presence of the slots. Two thin slots along the feeding CPW trace effectively block a strong leakage current component from flowing over the outer surface of the feeding coaxial cable. While not significantly affecting the antenna's VSWR performance over wide bandwidth, the slots have the effects of increasing the antenna gain in the azimuth plane and reducing the strengths of strong radiation lobes close to the direction of cable attachment especially in the low-frequency range.