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Ghasemifard, FatemehORCID iD iconorcid.org/0000-0002-9665-8557
Publications (10 of 29) Show all publications
Zetterström, O., Valerio, G., Mesa, F., Ghasemifard, F., Norgren, M. & Quevedo-Teruel, O. (2020). Dispersion Analysis of Periodically Loaded Transmission Lines with Twist Symmetry Using the Mode-Matching Technique. Applied Sciences, 10(17), Article ID 5990.
Open this publication in new window or tab >>Dispersion Analysis of Periodically Loaded Transmission Lines with Twist Symmetry Using the Mode-Matching Technique
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2020 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 10, no 17, article id 5990Article in journal (Refereed) Published
Abstract [en]

A mode-matching formulation is presented and used to analyze the dispersion properties of twist-symmetric transmission lines. The structures are coaxial lines periodically loaded with infinitely thin screens, which are rotated with respect to each other to possess twist symmetry. The results obtained using the proposed formulation are in good agreement with those of commercial simulators. Furthermore, using the presented mode-matching formulation, it is demonstrated that the propagation characteristics in the twist-symmetric structures are linked to the scattering and coupling of the higher order modes. The physical insight offered by this analysis is valuable for the design of various electromagnetic devices, such as filters, antennas, and phase-shifters.

Place, publisher, year, edition, pages
MDPI AG, 2020
Keywords
higher symmetry, mode-matching, twist symmetry
National Category
Physical Sciences
Identifiers
urn:nbn:se:kth:diva-283271 (URN)10.3390/app10175990 (DOI)000569664700001 ()2-s2.0-85090088891 (Scopus ID)
Note

QC 20201006

Available from: 2020-10-06 Created: 2020-10-06 Last updated: 2022-06-25Bibliographically approved
Alex-Amor, A., Ghasemifard, F., Valerio, G., Padilla, P., Fernandez-Gonzalez, J. M. & Quevedo-Teruel, O. (2020). Elliptical Glide-Symmetric Holey Metasurfaces for Wideband Anisotropy. In: 2020 14th European Conference on Antennas and Propagation (EUCAP 2020): . Paper presented at 14th European Conference on Antennas and Propagation (EuCAP), MAR 15-20, 2020, Copenhagen, DENMARK. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Elliptical Glide-Symmetric Holey Metasurfaces for Wideband Anisotropy
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2020 (English)In: 2020 14th European Conference on Antennas and Propagation (EUCAP 2020), Institute of Electrical and Electronics Engineers (IEEE) , 2020Conference paper, Published paper (Refereed)
Abstract [en]

This paper presents a mode-matching technique to study the dispersive features of periodic structures composed of glide-symmetric elliptical holes. As a difference from purely numerical methods, our formulation provides physical insight on the Floquet harmonics. At the same time, the computational cost is reduced compared to general purpose commercial software. The fields inside the holes are described by means of Mathieu functions and subsequently used to compute the full 2-D dispersion diagrams. With the presented analysis, we demonstrate that glide-symmetric periodic structures with elliptical holes offer anisotropic refractive indexes over a wide range of frequencies.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2020
Series
Proceedings of the European Conference on Antennas and Propagation, ISSN 2164-3342
Keywords
Modal analysis, mode-matching, elliptical holes, anisotropy, glide symmetry, wideband, dispersion properties
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-285739 (URN)10.23919/EuCAP48036.2020.9135517 (DOI)000564218701119 ()2-s2.0-85088652633 (Scopus ID)
Conference
14th European Conference on Antennas and Propagation (EuCAP), MAR 15-20, 2020, Copenhagen, DENMARK
Note

QC 20201113

Available from: 2020-11-13 Created: 2020-11-13 Last updated: 2022-06-25Bibliographically approved
Alex-Amor, A., Ghasemifard, F., Valerio, G., Ebrahimpouri, M., Padilla, P., Fernandez Gonzalez, J. M. & Quevedo-Teruel, O. (2020). Glide-Symmetric Metallic Structures With Elliptical Holes for Lens Compression. IEEE transactions on microwave theory and techniques, 68(10), 4236-4248
Open this publication in new window or tab >>Glide-Symmetric Metallic Structures With Elliptical Holes for Lens Compression
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2020 (English)In: IEEE transactions on microwave theory and techniques, ISSN 0018-9480, E-ISSN 1557-9670, Vol. 68, no 10, p. 4236-4248Article in journal (Refereed) Published
Abstract [en]

In this article, we study the wave propagation in a metallic parallel-plate structure with glide-symmetric elliptical holes. To perform this study, we derived a mode-matching technique based on the generalized Floquet theorem for glide-symmetric structures. This mode-matching technique benefits from a lower computational cost since it takes advantage of the glide symmetry in the structure. It also provides physical insight into the specific properties of Floquet modes propagating in these specific structures. With our analysis, we demonstrate that glide-symmetric structures with periodic elliptical holes exhibit an anisotropic refractive index over a wide range of frequencies. The equivalent refractive index can be controlled by tuning the dimensions of the holes. Finally, by combining the anisotropy related to the elliptical holes and transformation optics, a Maxwell fish-eye (MFL) lens with a 33.33% size compression is designed. This lens operates in a wideband frequency range from 2.5 to 10 GHz.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2020
Keywords
Periodic structures, Lenses, Dispersion, Refractive index, Anisotropic magnetoresistance, Harmonic analysis, Microwave theory and techniques, Anisotropy, dispersion analysis, elliptical holes, generalized floquet theorem, glide symmetry, Mathieu functions, metasurfaces, mode-matching, PPW
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-285745 (URN)10.1109/TMTT.2020.3011004 (DOI)000577949300018 ()2-s2.0-85092548361 (Scopus ID)
Note

QC 20201112

Available from: 2020-11-12 Created: 2020-11-12 Last updated: 2022-06-25Bibliographically approved
Arnberg, P., Petersson, O. B., Dahlberg, O., Ghasemifard, F. & Quevedo-Teruel, O. (2020). High Refractive Index Electromagnetic Devices in Printed Technology Based on Glide-Symmetric Periodic Structures. Applied Sciences, 10(9), Article ID 3216.
Open this publication in new window or tab >>High Refractive Index Electromagnetic Devices in Printed Technology Based on Glide-Symmetric Periodic Structures
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2020 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 10, no 9, article id 3216Article in journal (Refereed) Published
Abstract [en]

We demonstrate the beneficial effects of introducing glide symmetry in a two-dimensional periodic structure. Specifically, we investigate dielectric parallel plate waveguides periodically loaded with Jerusalem cross slots in three configurations: conventional, mirror- and glide-symmetric. Out of these three configurations, it is demonstrated that the glide-symmetric structure is the least dispersive and has the most isotropic response. Furthermore, the glide-symmetric structure provides the highest effective refractive index, which enables the realization of a broader range of electromagnetic devices. To illustrate the potential of this glide-symmetric unit cell, a Maxwell fish-eye lens is designed to operate at 5 GHz. The lens is manufactured in printed circuit board technology. Simulations and measurements are in good agreement and a measured peak transmission coefficient of -0.5 dB is achieved.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
glide symmetry, higher symmetries, Maxwell fish-eye lens, metasurface, periodic structures, printed circuit board
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-276912 (URN)10.3390/app10093216 (DOI)000535541900229 ()2-s2.0-85085112879 (Scopus ID)
Note

QC 20200622

Available from: 2020-06-22 Created: 2020-06-22 Last updated: 2024-03-15Bibliographically approved
Zetterström, O., Valerio, G., Mesa, F., Ghasemifard, F., Norgren, M. & Quevedo-Teruel, O. (2020). Mode-matching Analysis of Loaded Transmission Lines with Twist Symmetries. In: Proceedings 14th European Conference on Antennas and Propagation (EuCAP): . Paper presented at 14th European Conference on Antennas and Propagation (EuCAP), MAR 15-20, 2020, Copenhagen, DENMARK. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Mode-matching Analysis of Loaded Transmission Lines with Twist Symmetries
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2020 (English)In: Proceedings 14th European Conference on Antennas and Propagation (EuCAP), Institute of Electrical and Electronics Engineers (IEEE) , 2020Conference paper, Published paper (Refereed)
Abstract [en]

This paper studies the propagation characteristics in twist-symmetric structures by means of a mode-matching approach. The studied structures are coaxial transmission lines periodically loaded with 1- and 3-fold twist-symmetric infinitely thin sectorial sheets. The mode-matching formulation is validated with the commercial software CST Microwave Studio. In addition, the impact of adding twist symmetry to a coaxial line on the coupling of the higher order TM modes is discussed.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2020
Series
Proceedings of the European Conference on Antennas and Propagation, ISSN 2164-3342
Keywords
Higher symmetry, mode-matching, periodic structures, twist symmetry
National Category
Communication Systems
Identifiers
urn:nbn:se:kth:diva-285702 (URN)10.23919/EuCAP48036.2020.9135930 (DOI)000564218703074 ()2-s2.0-85088648789 (Scopus ID)
Conference
14th European Conference on Antennas and Propagation (EuCAP), MAR 15-20, 2020, Copenhagen, DENMARK
Note

QC 20210310

Available from: 2021-03-10 Created: 2021-03-10 Last updated: 2022-06-25Bibliographically approved
Ghasemifard, F., Mesa, F., Valerio, G. & Quevedo-Teruel, O. (2020). Propagation Characteristics in Substrate Integrated Holey Metasurfaces. In: Proceedings 14th European Conference on Antennas and Propagation (EuCAP): . Paper presented at 14th European Conference on Antennas and Propagation (EuCAP), MAR 15-20, 2020, Copenhagen, DENMARK. Institute of Electrical and Electronics Engineers (IEEE)
Open this publication in new window or tab >>Propagation Characteristics in Substrate Integrated Holey Metasurfaces
2020 (English)In: Proceedings 14th European Conference on Antennas and Propagation (EuCAP), Institute of Electrical and Electronics Engineers (IEEE) , 2020Conference paper, Published paper (Refereed)
Abstract [en]

In this paper we discuss the dispersion properties of a particular type of holey metasurfaces, named here "substrate integrated holey" (SIH) metasurface. SIH is a metallic holey structure manufactured in printed circuit board (PCB) technology by using densely metallized posts. We demonstrate that, differently to the case of holes fully covered with metal, in SIH, the height of the holes has a significant effect on the dispersion properties. In addition, in SIH metasurfaces, apart from the conventional stopband caused by its periodicity, there are stopbands due to the resonance modes trapped in the hole due to the posts. These stopbands are narrow and have a high rejection.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2020
Series
Proceedings of the European Conference on Antennas and Propagation, ISSN 2164-3342
Keywords
dispersion analyses, glide symmetry, metasurfaces, periodic structures, substrate integrated holes, SIH
National Category
Telecommunications
Identifiers
urn:nbn:se:kth:diva-285703 (URN)10.23919/EuCAP48036.2020.9135320 (DOI)000564218700150 ()2-s2.0-85088657117 (Scopus ID)
Conference
14th European Conference on Antennas and Propagation (EuCAP), MAR 15-20, 2020, Copenhagen, DENMARK
Note

QC 20210310

Available from: 2021-03-10 Created: 2021-03-10 Last updated: 2022-06-25Bibliographically approved
Alex-Amor, A., Valerio, G., Ghasemifard, F., Mesa, F., Padilla, P., Fernandez-Gonzalez, J. M. & Quevedo-Teruel, O. (2020). Wave Propagation in Periodic Metallic Structures with Equilateral Triangular Holes. Applied Sciences, 10(5), Article ID 1600.
Open this publication in new window or tab >>Wave Propagation in Periodic Metallic Structures with Equilateral Triangular Holes
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2020 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 10, no 5, article id 1600Article in journal (Refereed) Published
Abstract [en]

This paper studies wave propagation in a periodic parallel-plate waveguide with equilateral triangular holes. A mode-matching method is implemented to analyze the dispersion diagram of the structure possessing glide and mirror symmetries. Both structures present an unexpected high degree of isotropy, despite the triangle not being symmetric with respect to rotations of 90 degrees. We give some physical insight on the matter by carrying out a modal decomposition of the total field on the hole and identifying the most significant modes. Additionally, we demonstrate that the electrical size of the triangular hole plays a fundamental role in the physical mechanism that causes that isotropic behavior. Finally, we characterize the influence of the different geometrical parameters that conform the unit cell (period, triangle size, hole depth, separation between metallic plates). The glide-symmetric configuration offers higher equivalent refractive indexes and widens the stopband compared to the mirror-symmetric configuration. We show that the stopband is wider as the triangle size is bigger, unlike holey structures composed of circular and elliptical holes where an optimal hole size exists.

Place, publisher, year, edition, pages
MDPI, 2020
Keywords
metasurfaces, periodic structures, equilateral triangular holes, mode-matching, dispersion analysis, glide symmetry, mirror symmetry, isotropy
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-272887 (URN)10.3390/app10051600 (DOI)000525298100048 ()2-s2.0-85082448603 (Scopus ID)
Note

QC 20200529

Available from: 2020-05-29 Created: 2020-05-29 Last updated: 2022-06-26Bibliographically approved
Valerio, G., Ghasemifard, F., Norgren, M. & Quevedo-Teruel, O. (2019). A generalized mode-matching method for glide-symmetric structures. In: 2019 URSI International Symposium on Electromagnetic Theory, EMTS 2019: . Paper presented at 2019 URSI International Symposium on Electromagnetic Theory, EMTS 2019; San Diego; United States; 27 May 2019 through 31 May 2019. Institute of Electrical and Electronics Engineers (IEEE), Article ID 8931540.
Open this publication in new window or tab >>A generalized mode-matching method for glide-symmetric structures
2019 (English)In: 2019 URSI International Symposium on Electromagnetic Theory, EMTS 2019, Institute of Electrical and Electronics Engineers (IEEE), 2019, article id 8931540Conference paper, Published paper (Refereed)
Abstract [en]

The new discovery of the extraordinary properties of meta-surfaces possessing higher symmetries is encouraging new studies to better understand the fundamental role of the symmetry, as well as to produce efficient numerical methods for enabling a fast optimization. Here, we propose a mode matching technique to explain the operation of glide-symmetric fully-metallic surface made of holes of arbitrary shape. The mode-matching is formulated to take into account the glide symmetry of the unit cell and isolate its impact. This formulation leads to a reduction of the computational domain to a half cell, and to derive the symmetry properties of the modal fields propagating in the metasurface. Numerical results from commercial software are employed to validate our method.

Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE), 2019
Keywords
Computation theory, Electric fields, Commercial software, Computational domains, Efficient numerical method, Fast optimizations, Mode matching method, Mode matching technique, Symmetric structures, Symmetry properties, Numerical methods
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:kth:diva-268563 (URN)10.23919/URSI-EMTS.2019.8931540 (DOI)000526054600110 ()2-s2.0-85077953943 (Scopus ID)9781946815064 (ISBN)
Conference
2019 URSI International Symposium on Electromagnetic Theory, EMTS 2019; San Diego; United States; 27 May 2019 through 31 May 2019
Note

QC 20200331 QC 20200603

Available from: 2020-03-31 Created: 2020-03-31 Last updated: 2022-06-26Bibliographically approved
Shanei, M. M., Fathi, D., Ghasemifard, F. & Quevedo-Teruel, O. (2019). All-silicon reconfigurable metasurfaces for multifunction and tunable performance at optical frequencies based on glide symmetry. Scientific Reports, 9, Article ID 13641.
Open this publication in new window or tab >>All-silicon reconfigurable metasurfaces for multifunction and tunable performance at optical frequencies based on glide symmetry
2019 (English)In: Scientific Reports, E-ISSN 2045-2322, Vol. 9, article id 13641Article in journal (Refereed) Published
Abstract [en]

Dielectric metasurfaces have opened promising possibilities to enable a versatile platform in the miniaturization of optical elements at visible and infrared frequencies. Due to high efficiency and compatibility with CMOS fabrication technology, silicon-based metasurfaces have a remarkable potential for a wide variety of optical devices. Adding tunability mechanisms to metasurfaces could be beneficial for their application in areas such as communications, imaging and sensing. In this paper, we propose an all-silicon reconfigurable metasurface based on the concept of glide symmetry. The reconfigurability is achieved by a phase modulation of the transmitted wave activated by a lateral displacement of the layers. The misalignment between the layers creates a new inner periodicity which leads to the formation of a metamolecule with a new sort of near-field interaction. The proposed approach is highly versatile for developing multifunctional and tunable metadevices at optical frequencies. As a proof of concept, in this paper, we design a bifunctional metadevice, as well as a tunable lens and a controllable beam deflector operating at 1.55 mu m.

Place, publisher, year, edition, pages
NATURE PUBLISHING GROUP, 2019
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Electrical Engineering
Identifiers
urn:nbn:se:kth:diva-261952 (URN)10.1038/s41598-019-49395-4 (DOI)000487002100036 ()31541128 (PubMedID)2-s2.0-85072522293 (Scopus ID)
Note

QC 20191014

Available from: 2019-10-14 Created: 2019-10-14 Last updated: 2022-09-15Bibliographically approved
Ghasemifard, F., Alex-Amor, A., Valerio, G. & Quevedo-Teruel, O. (2019). Analysis and Applications of Glide-Symmetric Holey Metasurfaces. In: : . Paper presented at 21st International Conference on Electromagnetics in Advanced Applications (ICEAA) Granada, SPAIN SEP 09-13, 2019 (pp. 465-465). IEEE, 6
Open this publication in new window or tab >>Analysis and Applications of Glide-Symmetric Holey Metasurfaces
2019 (English)Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
IEEE, 2019
National Category
Other Physics Topics
Identifiers
urn:nbn:se:kth:diva-278920 (URN)000551337100137 ()
Conference
21st International Conference on Electromagnetics in Advanced Applications (ICEAA) Granada, SPAIN SEP 09-13, 2019
Note

QC 20201118

Available from: 2020-11-18 Created: 2020-11-18 Last updated: 2022-06-25Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9665-8557

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