Extracting UTD Wedge Diffraction Coefficients from Electric Field Measurements

The geometrical theory of diffraction (GTD) provides a powerful and computationally efficient framework for investigating real-world diffraction problems. Originally restricted to perfectly electrically conducting (PEC) wedges, the GTD and its uniform offspring have since been extended to wedges characterized by impedance surfaces (R. Tiberio et al., IEEE Trans. AP, 37, 2, 212-218, 1989). Though the impedance wedge solution provides a sound theoretical model for describing the field diffracted by numerous real-world edges, the impedance wedge solution is only applicable in cases where the material properties of the diffracting edge are known. Generally speaking, the data on the frequency-dependent permittivity and conductivity is extremely limited. More so, use of these values assumes that the diffracting body may be modeled as a smooth, solid, homogeneous wedge. The composition and internal geometry of the actual diffracting body as well as its external roughness may significantly alter how the edge diffracts any incident fields.