Diffraction characteristics of a slit in a thick conducting screen

Diffraction of a Plane Electromagnetic Wave by a Slot in a Conducting Screen of Finite Thickness Placed in Front of a Half-Infinite Dielectric

“…The obtained solution can be generalized also on the case when a more complex dielectric structure is placed behind a screen, which is formed by plane layers with various dielectric permittivity. Then, in Equations (7) and (13), the reflection coefficients for one boundary (10) should be replaced with appropriate reflection coefficients calculated for a layered dielectric structure as a whole.…”

“…, one should take into consideration the boundary conditions on the conducting surfaces z = −l and z = l. Then, instead of a continuous distribution in mode parameter (3) we have a sum over an infinite discrete series of mode propagation parameters [10,11,16] …”

“…That is why the problem of simulation of a plane wave diffraction by slots in conducting screens, as well the like problem of diffraction by a complementary screen in the form of a strip, is of great interest [2,3,[8][9][10][11][12][13][14]. The classic statement of these problems proceeds from the premise of a conducting screen having infinitesimal thickness [1,2,8,9].…”

“…This approach is based on the mode-matching method [2], which looks like the method used in the rigorous diffraction theory [1,8,9]. It provided the possibility to obtain the solutions [3][4][5][6][10][11][12][13], which may be unwieldy, but is greatly simple than the rigorous solution for a screen of infinitesimal thickness [15] and is convenient for computer programming. However, the solutions obtained by the mode-matching method, are applicable only in the cases when thickness of a screen with a slot is in the order of the wavelength of diffracted radiation or more.…”

“…However, the solutions obtained by the mode-matching method, are applicable only in the cases when thickness of a screen with a slot is in the order of the wavelength of diffracted radiation or more. For small values of thickness a computation algorithm is unstable and yields false results [10,11] since the system of amplitude equations on interfaces becomes ill-conditioned. To avoid this disadvantage, in [16] it was proposed to apply additionally the Tikhonov regularization procedure [17] to such a system.…”