Journal ArticleDOI
Soft and hard horn antennas
Erik Lier,Per-Simon Kildal +1 more
TLDR
Horn antennas with soft and hard boundaries are analyzed and the dependency between the edge taper directivity, and sidelobes is calculated based on the solution to the spherical hybrid modes in a conical horn with arbitrary wall impedances.Abstract:
Horn antennas with soft and hard boundaries are analyzed. A soft boundary which exists in classical hybrid-mode horns gives zero field intensity at the wall. A hard boundary corresponds to a uniform field distribution over the horn aperture. Soft and hard horn antennas are compared with respect to directivity, sidelobes, and beamwidth. The dependency between the edge taper directivity, and sidelobes is also calculated based on the solution to the spherical hybrid modes in a conical horn with arbitrary wall impedances. This makes it possible to study how to compromise between directivity and sidelobes. Also discussed is how the different wall impedances may be realized, and some preliminary experimental work on hard horns is presented. >read more
Citations
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Journal ArticleDOI
Local Metamaterial-Based Waveguides in Gaps Between Parallel Metal Plates
TL;DR: The ridge gap waveguide as mentioned in this paper is a metamaterial-based waveguide that can be realized in a narrow gap between two parallel metal plates by using a texture or multilayer structure on one of the surfaces.
Journal ArticleDOI
Artificially soft and hard surfaces in electromagnetics
TL;DR: 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.
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.
Proceedings Article
Three metamaterial-based gap waveguides between parallel metal plates for mm/submm waves
TL;DR: In this article, the basic ideas of how local waveguides and transmission lines can be designed to propagate along desired paths in the air gap between two metal surfaces are presented, related to the performance of artificial magnetic conductors, EBG surfaces and soft and hard surfaces.
Journal ArticleDOI
Forward and backward leaky wave radiation with large effective aperture from an electronically tunable textured surface
TL;DR: In this paper, a textured surface is used as an electronically steerable leaky wave antenna, by coupling energy into a leaky band, and tuning the surface to change the radiation angle.
References
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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 dielectric hybrid mode antenna feed: A simple alternative to the corrugated horn
TL;DR: In this paper, a hybrid-mode horn antenna has been analyzed theoretically and experimentally, which consists of a conical metal horn with a dielectric core inside, separated from the metal wall by another layer with lower permittivity than for the core material.
Journal ArticleDOI
Simple hybrid mode horn feed loaded with a dielectric cone
TL;DR: A conical horn loaded with a solid dielectric cone, separated from the metal wall by a thin layer of low-permittivity material or air, is analyzed theoretically and tested experimentally as mentioned in this paper.
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.
Journal ArticleDOI
Design of corrugated conical horns
TL;DR: In this paper, the effects of horn aperture size, slot width-to-pitch ratio and frequency on the cross-polarization of the radiation pattern are considered, as well as the range of slot parameters which can be used and the design of the slots near the throat of the horn to achieve a low VSWR for bandwidths of 1.5 to 1.