Surface-wave luneberg lens antennas

Walter, C.

doi:10.1109/tap.1960.1144896

Cited by 45 publications

(22 citation statements)

References 7 publications

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“…A dielectric filled parallel holey metal plate operated in TE 01 mode could in principle be used in Luneburg Lens applications since this structure is capable of providing a refractive index from nearly zero to a value approaching the square root of the dielectric between the plates, [5]. This method relies on the theory that a waveguide with holes drilled in it can yield variation of equivalent refractive index, [6].…”

Section: Luneburg Lens Designmentioning

confidence: 99%

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Printed holey plate Luneburg lens

Xue

Fusco

2007

Micro & Optical Tech Letters

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Effects of thermal annealing of W/SiO 2 multilayer Bragg reflectors on resonance characteristics of film bulk acoustic resonator devices with cobalt electrodes, J Vac Sci Technol A 22 (2004), 465-471. 6 a lens composed of a dielectric filled planar parallel-plate operating in the TEM mode was described. This time the dielectric gradation was achieved by a combination of circular and triangular dispersed equivalent volume-averaged relative permittivity control as well as transverse resonance guided permittivity thickness control. However, all of the methods above require considerable fabrication process duration due to numerous holes or posts having to be machined; in addition the lenses realized can be difficult to integrate with active circuits. In this article we detail the design and performance of a surface wave Luneburg lens operated in TE 01 mode in Ka band. The lens gradient dielectric constant is realized by photo lithographically etching holes of different sizes into one side of a standard PCB ground plane. In this way we introduce local inductive variation which partially neutralizes the intrinsic permittivity of the material in prespecified localized regions of the lens, i.e. gives local permittivity gradation control. For verification, a prototype lens was designed and fabricated; measurement and simulation results show good agreement. LUNEBURG LENS DESIGNThe lens plane of a planar Luneburg lens is a circle of unit radius whose index of refraction n varies with the radius r according to, [1]:The lens n is maximum at its center r ϭ 0 (n ϭ ͱ2), and decreases gradually to the periphery r ϭ 1 (n ϭ 1), i.e. total variation of ⌬n ϭ ͱ2 Ϫ 1 Ϸ 0.414.A dielectric filled parallel holey metal plate operated in TE 01 mode could in principle be used in Luneburg Lens applications since this structure is capable of providing a refractive index from nearly zero to a value approaching the square root of the dielectric between the plates, [5]. This method relies on the theory that a waveguide with holes drilled in it can yield variation of equivalent refractive index, [6]. When circular holes arranged in rectangular lattice are introduced into one of the metal plates as shown in Figure 1, the equivalent refractive index n holes is given by [5] as:Here, b and c are the spacing between the neighboring holes along X ជ and Y ជ direction, respectively. For isotropy approximation c is made equal to b and both are restricted to be smaller than g /2, d is the diameter of the holes; r is the permittivity of the filled dielectric, g is the guided wavelength of the solid ground parallel plate, and a is the plate spacing. The electric field polarized in Y ជ direction, propagates along X ជ .The lens was designed according to [7] using only three discrete concentric cylindrical layers of respective values n ϭ 1.22, 1.34, 1.4. This was done to ease the demand on the (2) it can be seen that the value of n can only be increased by the introduced holes, thus the operating frequency is chosen such that we have n equal to 1.22 in the le...

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Section: Luneburg Lens Designmentioning

confidence: 99%

“…This method relies on the theory that a waveguide with holes drilled in it can yield variation of equivalent refractive index, [6]. When circular holes arranged in rectangular lattice are introduced into one of the metal plates as shown in Figure 1, the equivalent refractive index n holes is given by [5] as:…”

Section: Luneburg Lens Designmentioning

confidence: 99%

Printed holey plate Luneburg lens

Xue

Fusco

2007

Micro & Optical Tech Letters

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“…In order to check the validity of the master design equation (2.5), given below, [13], a model lens is simulated at 24GHz for operation under TE 01 (a = 5mm) mode propagation; Fig. 2.10 shows the conceptual of the model structure.…”

Section: (22) Holey Plate Lensmentioning

confidence: 99%

Electronically Reconfigurable Microwave Lens Antennas

Xue¹,

Fusco²

2005

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The purpose of this report is to present the results of further investigations into the operation and design of two-dimensional Luneburg Lenses at 24 GHz, with the possibility for electronic control of their behavior. Various lens design techniques are illustrated; these include a holey dielectric lens (drilled dielectric) and, a holey plate lens (etched holes on the upper metal plate). Ray tracing theory is presented which shows the general properties of the gradient index lens. These results indicate that it may be possible to synthesize a tuneable lens whose focal length and /or radiation pattern can be adjusted by electronic modification of the lens dielectric properties. In addition a uniform outer layer lens and a two-shell lens are also demonstrated. Some preliminary investigations are presented with regard to the general properties of Liquid Crystal materials for tuneable lens use. Also we present preliminary design work on a MMIC reflection amplifier for ultimate deployment in active planar lens reflector for RCS enhancement. 1 Report Documentation Page Form Approved OMB No. 0704-0188Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number.

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“…Two techniques can be employed to achieve this confinement. The first is to fill a thin, curved waveguide [16] with the index distribution, and the second is to utilise surface wave propagation. Surface wave supporting structures, with a variable refractive index, can be achieved with metasurfaces [17] or dielectric slabs (varying thickness or permittivity).…”

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confidence: 99%

Perfect Surface Wave Cloaks

et al. 2013

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This paper presents a general approach to design surface wave cloaks which circumvent the problems associated with superluminal phase velocities and anisotropy. The cloaks proposed in this paper are very thin, just a fraction of a wavelength in thickness, yet can cloak electrically large objects. This solution combines curved, rotationally symmetric geometries with isotropic radially dependent refractive index profiles to achieve perfect cloaking. Three refractive index profiles are obtained: an anti-fish eye, a conical cloak and a cosine cloak, and each is simulated using a fullwave solver. The performance is analysed using dielectric filled waveguide geometries, and the curvature of the surface is shown to be rendered invisible, hiding any object positioned underneath. For the cosine cloak, a transformation of the required dielectric slab permittivity was performed for surface waves propagation, demonstrating the practical applicability of this technique.

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Surface-wave luneberg lens antennas

Cited by 45 publications

References 7 publications

Printed holey plate Luneburg lens

Printed holey plate Luneburg lens

Electronically Reconfigurable Microwave Lens Antennas

Perfect Surface Wave Cloaks

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