Tapered impedance loading for suppression of edge scattering

Tapered impedance loading is studied to suppress edge scattering from a rectangular metallic plate. Associated with the pattern multiplication theorem, a simple approach to this scattering problem is proposed assuming the current distribution of the target is broken into an array of overlapping triangles. This tapered impedance is realised by geometric variations based on frequency-selective surfaces concepts. Electromagnetic back-scattering of the as-prepared target from a rectangular plate with edge tapered impedance loading is analysed for both horizontal polarisation and vertical polarisation, and compared with that from one of the same shape but loaded with constant or no impedance on the edge. It is found that the proposed tapered impedance loading advances the wide angular radar cross section reduction of the target further than the other designs, and works with the change of the azimuth angular of incidence wave, solving the problem met by the popular trailing-edge serration method.