3-D Implementation of Transformation Optics Using a Tetrahedron-Based Meshing Technique and Homogeneous Materials

Kazemzadeh, Mohammadrahim; Alighanbari, Abbas

doi:10.1109/tap.2017.2700886

Cited by 6 publications

(13 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Transformation optics (TO) [1] has attracted interests in various fields, including antennas [2][3][4][5][6][7][8], microwave devices [9][10][11][12][13][14][15][16][17][18][19][20], and invisibility and external cloaks [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. Most of the previous work deal with two-dimensional (2-D) problems and only few consider three-dimensional (3-D) methods, including the recent works of the authors [20,29,30]. Also, the materials obtained via TOs are generally complex and can be inhomogeneous with singularities.…”

Section: Introductionmentioning

confidence: 99%

“…To reduce the complexity, some of the previous work use conformal mapping [8,14,15,40] and some use piece-wise homogeneous materials [13,16,17,19,20,29,30]. Most of these methods are inherently 2-D.…”

Section: Introductionmentioning

confidence: 99%

“…In [20,29], polyhedral and tetrahedral meshing have been used to divide the 3-D space into some regions and a linear transformation is applied to each region. The Jacobean matrix of the transformation determines the material.…”

Section: Introductionmentioning

confidence: 99%

“…A non-orthogonal coordinate system is assigned to each region (segment), then, an appropriate transformation is applied to the principal vectors of the coordinate system in the region. By transforming a set of vectors, instead of a set of points [20], it will be easy to find a combination of transformations through which the volume of the transformed region is conserved. The volume conservation leads to material simplification and makes the transformed material identical to free space in some regions.…”

Section: Introductionmentioning

confidence: 99%

“…The bend is made of two polyhedral regions and one 2-D (homogeneous) material. In the previous work [20], the same coupler needed six tetrahedral regions and six different materials. Also, a resize coupler with a rotated output port is demonstrated which uses only one 2-D material.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Variation of device topology for material simplification as three‐dimensional transformation optics methodology

Kazemzadeh¹,

Alighanbari²

2019

IET Microwaves, Antennas & Propagation

Self Cite

View full text Add to dashboard Cite

A three‐dimensional (3‐D) transformation optics (TO) methodology is presented using polyhedral meshing and homogeneous materials, in which, the topology of the device is varied, in order to achieve material simplification. The device is divided into a minimal number of polyhedral segments, and a linear transformation is applied to each polyhedron. The polyhedrons and transformations are tried to be chosen so that the volume is conserved through the transformation, and if possibly, some transformed materials are equivalent to free space. A few 3‐D waveguide coupler and carpet cloak problems are solved to demonstrate and evaluate the proposed methodology. For instance, it is shown that a right‐angle 3‐D rectangular waveguide bend can be designed using only one two‐dimensional (2‐D) homogeneous material. Also, resize couplers are designed using only one or two 2‐D homogeneous materials. A carpet cloak is demonstrated which uses only two material types, filling five polyhedral meshing segments. Similar problems would have required much larger number of meshing segments and material types, using previous methods. Therefore, using the proposed methodology, 3‐D TO‐based guiding and cloaking devices will be more feasible. Furthermore, a 3‐D finite difference time domain (FDTD) method is developed to verify the results of some examples.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Variation of device topology for material simplification as three‐dimensional transformation optics methodology

Kazemzadeh¹,

Alighanbari²

2019

IET Microwaves, Antennas & Propagation

Self Cite

View full text Add to dashboard Cite

show abstract

General design of 3D piecewise homogeneous illusion devices with arbitrary shapes

Yang

Huang

Yang

et al. 2020

Journal of Applied Physics

View full text Add to dashboard Cite

In this work, a general method is presented for the design of arbitrarily shaped 3D illusion devices with piecewise homogeneous parameters based on geometric divisions and linear coordinate transformations. Three illusion devices that can reshape the sizes or positions of the wrapped objects are demonstrated, namely, shrinking, amplifying, and shifting devices. The shrinking device can shrink a larger object into a smaller one with different material parameters, whereas the amplifying device can enlarge a smaller object into a larger one, and a shifting device can generate a new image with an identical size but located at a different position. In addition, based on the presented shrinking device, a perfect 3D invisibility cloak is achieved by shrinking the wrapped object to sufficiently small dimensions as compared to the operating frequency. An electromagnetic concentrator is also obtained by replacing the coated object of the amplifying device with a compression medium. The presented design approach can be easily extended to the design of other electromagnetic devices and even to other physical fields. It is believed that the presented piecewise homogeneous devices are more practicable in reality and can accelerate the potential applications of illusion devices in both military and commercial fields.

show abstract

Experimental demonstration of invisible electromagnetic impedance matching cylindrical transformation optics cloak shell

Chen

Wang

Cheng³

et al. 2018

J. Opt.

View full text Add to dashboard Cite

The realization of an ideal invisible cloak implementing transformation optics is still missing. An impedance matching concept is implanted into transformation optics cloak to generate an impedance matching cloak (IMC) shell. In this work, it is proved that impedance matching structure reduces the cloaking structure’s disturbance to a propagating electromagnetic field and improves its invisibility measured by scattering field intensity. Such a cylindrical IMC shell is designed, fabricated with proposed rounded rectangular split-ring-resonators (RR-SRRs), and experimental measurements show the total scattering field of a perfect electric conductor (PEC) cylinder surrounded by an IMC shell is improved greatly compared to the PEC cylinder showing electromagnetic wave front ripple suppression and a considerable scattering shrinking effect. IMC shell backward scattering field is suppressed down to 7.29%, compared to the previous value of 86.7% due to its impedance matching character, and overall scattering field intensity shrinking is down to 19.3% compared to the previously realized value of 56.4%. Sideward scattering field recorded in the experiment also has a remarkable improvement compared to the PEC cylinder. The impedance matching concept might enlighten the realization of an ideal cloak and other novel electromagnetic cloaking and shielding structures.

show abstract

3-D Implementation of Transformation Optics Using a Tetrahedron-Based Meshing Technique and Homogeneous Materials

Cited by 6 publications

References 44 publications

Variation of device topology for material simplification as three‐dimensional transformation optics methodology

Variation of device topology for material simplification as three‐dimensional transformation optics methodology

General design of 3D piecewise homogeneous illusion devices with arbitrary shapes

Experimental demonstration of invisible electromagnetic impedance matching cylindrical transformation optics cloak shell

Contact Info

Product

Resources

About