Diffraction Field Behavior Near the Edges of a Slot and Strip

Abstract

Abstract-The diffraction field asymptotics on the edges of a slot in the plane conducting screen and of a complementary strip is considered using the exact solutions of corresponding stationary diffraction problems, which have been derived before on the bases of the slot (strip) field expansions into discrete Fourier series. It is shown that as nearing the slot (strip) edges, the fields decrease or increase indefinitely in magnitude by the power law with an exponent of modulus less than unity, so the given exact diffraction solutions yield finite value of electromagnetic energy density in any point of space.

Rigorous methods for solving the problems of electromagnetic diffraction by slot obstacles

“…Our computations show that the edge asymptotics for diffraction fields corresponds to a power function with the exponent less than unite in magnitude (Fig. 4) [9]. This result provides finiteness of the field energy in any arbitrary small space domain on the edge.…”

“…This value (of the order of 0.6 and 0.4) differs from that for isolated half-plane (0.5 -the Sommerfeld's solution [2,8]), but at sufficiently great width of a slot (strip), it turns, naturally, to the Sommerfeld's value. Admittedly, evaluation shows that this limit is reached, when the product of the wavelength and the slot half-width is not less then 1000 [9].…”

“…Diffraction by a slot (left) and strip (right) Exponent T, determining the power field asymptotics on the edges of a slot and strip for two different field polarizations (H and E)[9].…”