The characteristics of a wideband ESPAR antenna using Koch fractal shaped elements

This article suggests a new 5-element electrically steerable passive array radiators (ESPAR) antenna using a Koch fractal structure for the purpose of adding wideband characteristics to the conventional ESPAR antenna, and its characteristics were confirmed through design and fabrication. The Koch fractal ESPAR antenna with a monopole structure where two crossed boards stand vertically on a circular ground has four parasitic elements arranged around a single active element with a fixed radius and reactance is loaded on each parasitic element. It satisfied the return loss less than −15 dB from 1.7 to 2.4 GHz on the 700 MHz band and showed directivity and gain that have similar radiation patterns according to frequency. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2108–2112, 2015