Metal Screen Influence on the Resonant Length of a Wire Antenna

Abstract

With the method of induced electromotive forces and the uniform geometric diffraction theory the algorithm for calculating the input impedance of the symmetric electric dipole placed above the metal infinitely thin rectangular screen is developed. The half-wave dipole resonance arm at which the jet part of its input impedance is equal to zero is determined vs. dipole thickness, sizes and form of the screen for different dipole-to-screen distances and dipole orientations towards the screen. It is shown that presence of the screen results in greater shortening of the dipole resonant length than in the case of the dipole in free space.