Modification and control of currents on monopole antennas using magnetic bead loading

Abstract

Several methods to modify the currents on electrically long monopole antennas are investigated. The radiation pattern, input impedance, and resonant frequency are calculated for several configurations of monopoles loaded with magnetic materials, both as coatings and as small beads. Proper application of such loading is shown to cause the radiated fields and resonant frequency to mimic a shorter quarter-wave monopole.