Journal ArticleDOI
Artificially soft and hard surfaces in electromagnetics
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TLDR
In this paper, the concept of soft and hard surfaces is treated in detail, considering different geometries, and it is shown that both the hard and soft boundaries have the advantage of a polarizationindependent reflection coefficient for geometrical optics ray fields, so that a circularly polarized wave is circularly polarization in the same sense after reflection.Abstract:Â
A transversely corrugated surface as used in corrugated horn antennas represents a soft boundary. A hard boundary is made by using longitudinal corrugations filled with dielectric material. The concept of soft and hard surfaces is treated in detail, considering different geometries. It is shown that both the hard and soft boundaries have the advantage of a polarization-independent reflection coefficient for geometrical optics ray fields, so that a circularly polarized wave is circularly polarized in the same sense after reflection. The hard boundary can be used to obtain strong radiation fields along a surface for any polarization, whereas the soft boundary makes the fields radiated along the surface zero. >read more
Citations
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Journal ArticleDOI
High-impedance electromagnetic surfaces with a forbidden frequency band
TL;DR: In this paper, a new type of metallic structure has been developed that is characterized by having high surface impedance, which is analogous to a corrugated metal surface in which the corrugations have been folded up into lumped-circuit elements and distributed in a two-dimensional lattice.
Journal ArticleDOI
Reflection phase characterizations of the EBG ground plane for low profile wire antenna applications
Fan Yang,Yahya Rahmat-Samii +1 more
TL;DR: In this article, the authors focus on the reflection phase feature of EBG surfaces, which can be used to identify the input-match frequency band inside of which a low profile wire antenna exhibits a good return loss.
Journal ArticleDOI
Two-dimensional beam steering using an electrically tunable impedance surface
TL;DR: In this article, a periodic surface texture is used to alter the electromagnetic properties of a metal ground plane by covering the surface with varactor diodes, and a tunable impedance surface is built, in which an applied bias voltage controls the resonance frequency and the reflection phase.
Book
Electromagnetic Band Gap Structures in Antenna Engineering
Fan Yang,Yahya Rahmat-Samii +1 more
TL;DR: In this paper, the FDTD method for periodic structure analysis is used for periodic structures analysis of EBG surfaces and low profile wire antennas are used for EBG surface wave antennas.
Journal ArticleDOI
Design and experimental verification of ridge gap waveguide in bed of nails for parallel-plate mode suppression
Per-Simon Kildal,Ashraf Uz Zaman,Eva Rajo-Iglesias,Esperanza Alfonso,Alejandro Valero-Nogueira +4 more
TL;DR: In this paper, the ridge gap waveguide is used to verify the large bandwidth and low losses of the quasi-transverse electromagnetic (TEM) mode propagating along the guiding ridge.
References
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Book
Time-harmonic electromagnetic fields
TL;DR: In this paper, a revised version of the Revised edition of the book has been published, with a new introduction to the concept of plane wave functions and spherical wave functions, as well as a detailed discussion of the properties of these functions.
Journal ArticleDOI
A uniform geometrical theory of diffraction for an edge in a perfectly conducting surface
R.G. Kouyoumjian,P.H. Pathak +1 more
TL;DR: In this article, a compact dyadic diffraction coefficient for electromagnetic waves obliquely incident on a curved edse formed by perfectly conducting curved plane surfaces is obtained, which is based on Keller's method of the canonical problem, which in this case is the perfectly conducting wedge illuminated by cylindrical, conical, and spherical waves.
Journal ArticleDOI
Definition of artificially soft and hard surfaces for electromagnetic waves
TL;DR: The widely used transversely corrugated surfaces and other alternative surfaces having the same anisotropic surface impedance deserve a common name as discussed by the authors, and it is proposed to call them soft surfaces by analogy with the soft surfaces in acoustics.
Journal ArticleDOI
A method of synthesizing radiation patterns with axial symmetry
H.C. Minnett,B. Thomas +1 more
TL;DR: Symmetrical radiation feed patterns which are consequence of specified form of hybrid mode fields as disclosed by focal plane analysis are described in this article, where the authors show that the feed pattern is a consequence of the hybrid mode field.