Diffraction of high-frequency electromagnetic waves by curved strips

Abstract

A bstract-The construction of a high-frequency solution in the geometrical theory of diffraction (GTD) format for the generation of edge-diffracted space rays and edge-excited surface waves by an electromagnetic wave normally incident on the edge of a curved impedance strip is discussed. The transformation coefficients necessary for the analysis of the diffraction on curved surfaces with equal or vanishing face impedances are tabulated in a form appropriate for numerical applications. The procedure for evaluating the diffracted field excited by the edge of a cylindrically curved strip, which can be associated with a reflector antenna or an aperture on a curved surface, is presented for both perfectly and nonperfectly conducting cases.

A Novel UTD-Type Diffraction Coefficient for a Straight Edge in a Curved Screen

“…7(c). Edge diffraction of these WG rays as discussed in [15] can be summarized as v s ∼ṽ i (E1) ·Tew (ϕ k ) ·Πw12 (E1, E2) ·Twe (ϕ) ·Πo2p (E2, p) (28) where from (1) and Fig. 1(c) v i (E1) = exp(j · ka · cos(θ + θo)) (29a) Fig.…”

“…The creeping to creeping coefficientTcc and the surface to observation phase factorΠoMp is given as [15] Tcc = jka/(4 ·υn · (υn − ka)) (33a)…”

“…Diffraction of plane wave by straight edge in PEC curved screen has been a subject of interest for quite some time. Idemen [14] and Serbest et al [15] obtained nonuniform solutions valid away from the edge transition regions. Chuang and Liang [16] and Michaeli [17] obtained uniform solutions in limited angular range of diffraction space by considering the problem of surface and edge diffractions in sequential manner.…”