Suppression of Surface Wave from Finite Conducting Surfaces with Impedance Loading at Margins

Abstract

The use of impedance loading to suppress edge scattering of surface wave from finite conducting surface is proposed. Electromagnetic back-scattering from the finite conducting surfaces with impedance loading at margins is analyzed for horizontal and vertical polarizations, and compared with that of the wave scattering from the target of the same shape but having no impedance loading at margins. The location of impedance loading is determined by analyzing the Poynting flux of surface wave on the surface. The impedance loading at margins can suppress surface waves from finite conducting surfaces, which can be regarded as a two-dimensional (2-D) version of the one dimension (1-D) Salisbury screen. By changing the impedance value and the width of the impedance loading boundaries, and keeping the center frequency invariable, the relationship between these parameters and the suppression effect of edge scattering is established. The margin impedance loading is effective for plane wave incidence at large angles (low grazing angles) with the considered finite conducting surfaces. Such a way of margin impedance loading can remarkably reduce the mono-static radar cross sections (RCS) at low frequency band, and the method of the absorbing coating is proved not effective enough.