Shielding effect of a thick screen with corrugations

Abstract

Abstract-The shielding effectiveness of a corrugated thick screen is theoretically and experimentally investigated. This screen consists of a half-plane of finite thickness in which corrugations are etched on the smaller side. This structure provides a significant attenuation in the shadow region for both polarizations of the incident field; thus, it can be effectively used for protecting apparatuses from radiating interference as well as for decoupling nearby operating antennas. The shielding properties of the screen are described by a highfrequency formulation that involves closed-form expressions.An experimental setup at X X X band has been arranged to test the effectiveness of a corrugated screen; the field in the shadow region is compared with that of a screen without corrugations. The experimental results compare very well with those obtained by the high-frequency expressions.

An Efficient Algorithm for the Computation of the UTD $T$ Transition Function

“…However, each individual GFI in (6) exhibits singularities which are not present in the function. Therefore the use of (6), which is in general redundant, is also numerically not robust in correspondence of GFI singularities, and an alternative algorithm for the direct calculation of is in order.…”

“…Finally, a third representation of can be given in terms of the GFI as (6) in which GFI is defined as [2], [15] ( 7) and (8) are such that (9) The outline of the derivation of (6) from (2) is given in Appendix A. Expression (6) allows the analytical extension of to the case where and are either both real or imaginary and is real but 1, and the case where is real and and are both imaginary.…”

Time domain double diffraction at a pair of coplanar skew edges

“…The introduction of the angles and , which automatically appear in our spectral synthesis, is convenient to parameterize the DD-field as a ray. In (13), and exhibit pole singularities that independently occur in the two variables of integration. Eventually, the change of variables and is performed, leading to (15) in which the integration contours and are now translated and thus defined along and , respectively.…”

“…Then, all the fields radiated by edge 2 (12) are superposed for each -spectral spherical source in (10), i.e., in (10) is replaced by , leading to the double integral representation (13) In (13), is the distance between the spectral source and observation whose explicit expression is (14) with (note that being the unit vectors and orthogonal to the plane containing the two edges). The introduction of the angles and , which automatically appear in our spectral synthesis, is convenient to parameterize the DD-field as a ray.…”

“…First, it has been obtained by a suitable wavefront approximation, as demonstrated in [4]- [6] in general terms. Second, it is shown that the present uniform wavefront approximation for TD-DD field is the exact Fourier transform of the uniform expression for FD-DD field obtained in [12], whose accuracy has been proved at high-frequency in [12], [15], [13] against Method of Moments (MoM) and measurement results in various geometric configurations. The TD-DD field response to a general pulsed excitation is obtained via convolution between the exciting pulse and the impulsive DD response, as shown in Section VIII.…”