Electromagnetic scattering by open circular waveguides

Abstract

The calculation of the radar scattering characteristics of open circular waveguides is approached by the Wiener‐Hopf technique. The Wiener‐Hopf factorization functions are calculated by numerical integration, and these results are compared to dc and high‐frequency asymptotic approximations. The exact Wiener‐Hopf solutions for scattering, coupling, and reradiation by semi‐infinite circular waveguides are then computed for representative cases including axial backscatter with no internal obstacles, and backscatter based on the coupling to and radiation from individual waveguide modes. Finally, the high‐frequency asymptotic solution for axial backscatter is transformed into the time domain and compared to the result of numerical transformation of the backscatter results obtained from numerical integration.

Radar cross‐section reduction studies of partially open cavity structures

“…If H = a , the offset of the end-plate is exactly one diameter. When H = 0, (6) reduces to (5). Note that for the Sbend cylinder, a cross-sectional view at any z = constant plane also yields a perfect circle.…”

Electromagnetic Plane Wave Excitation of an Open-Ended, Finite-Length Conducting Cylinder

“…References [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] give an indication of the diversity of techniques and longevity of this and related wave problems. The semi-infinite cylinder is amenable to the classic Wiener-Hopf technique (for example [1]), while a fairly involved modification to treat the cylinder of finite length is described in [2].…”

“…Many of the applications ( [6,8,[9][10][11][12][13][14][15][16][17]) are concerned with the far-field scattering (radar cross section or RCS) from such a target. A formulation of the boundary value problem as a Fredholm integral equation for the surface currents [20] is the usual foundation for the class of numerical approaches referred to as the "moment method" [1 1] , the "method of weighted residuals" [18], or some related Galerkin technique [2 1 , 22] .…”

“…High frequency studies [12][13][14][15] demonstrate some progress toward this important aspect of the cavity-scattering problem. Fourier transformation to the time domain is addressed in [16], [17], and [19].…”

<title>Reduction of radar image artifacts caused by target inlets</title>

“…If we substitute2°e i2Lk2-k = 2 ik2 k,m f JO (2kc,mVx/F2 L2) e j2k dx" , (8) where Jo(e) is the Bessel function of the first kind, then we can write Im(X) = 2 i dx" Jo (2kc,mX2 L2) 1k2 dk 1 (kc,m/k)2 ei2k_x") .…”