Article
Engineering, Electrical & Electronic
Hanxuan Li, Bo Li, Lei Zhu
Summary: “A novel direct synthesis method for wideband linear-to-circular polarizers on 3-D frequency selective structures is proposed. The synthesis method utilizes two orthogonal linearly polarized transmission paths to achieve circularly polarized transmission, and introduces new conditions of phase difference and phase slope to replace the typical phase condition. The proposed method is validated through theoretical investigations and fabrication of a design example, showing wide axial ratio bandwidth and low insertion loss. This synthesis method provides a promising solution for designing other types of wideband linear-to-circular polarizers.”
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Emilio Arnieri, M. Salucci, F. Greco, L. Boccia, A. Massa, G. Amendola
Summary: A dual-band, wide-bandwidth and wide-angle scanning circular polarizer is designed to convert linearly polarized waves into right- and left-hand circularly polarized waves. An analytic model and closed-form expressions are used for design and optimization, and a system design method is proposed for performance improvement. Experimental results show that the polarizer maintains a low axial ratio within a wide-angle field of view.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
E. Arnieri, F. Greco, G. Amendola
Summary: The study presents a broadband and wide-angle scanning linear polarization to circular polarization converter based on a dual-layer structure, using conventional Jerusalem crosses as the elementary cell. The design is based on a transmission line circuit model and full-wave simulations, with a generalized equivalent circuit that includes oblique incidence. Simulated results show a 24% axial ratio bandwidth for a wide range of incidence angles in both xz and yz planes, highlighting the converter's unique combination of wide bandwidth, thin profile, and stable response to the angle of incidence. It can be integrated into any LP antenna system to generate CP without significantly affecting antenna performance.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Raul Rodriguez-Berral, Francisco Mesa, Francisco Medina
Summary: This paper presents an eigenvalue problem to identify the characteristic resonances of a 2-D periodic distribution of planar metallic symmetric patches within the nondiffraction frequency regime. The eigenvalues and eigenfunctions obtained from solving the problem are used to expand a general solution under oblique illumination conditions. Additionally, this work proposes a method to determine accurate values of the capacitive and inductive components for an equivalent circuit, which is validated by comparing with results computed using existing software.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Cesar L. Valle, Gilbert T. Carranza, Raymond C. Rumpf
Summary: An algorithm is presented for generating frequency selective surfaces (FSSs) that can adapt to any curvature while maintaining the desired properties. The algorithm is independent of both element design and surface curvature, enabling the user to design FSSs for curved surfaces while preserving their response compared to flat arrays. It provides two standard tessellation language (STL) files, one describing the curved surface and the other the FSS elements placed on it, making it suitable for 3D printing and flexible electronics. The algorithm's effectiveness is demonstrated through simulations and measurements on various surfaces, including a non-symmetrical parabolic dome.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Mondeep Saikia, Kumar Vaibhav Srivastava
Summary: This article introduces a method that utilizes the modulation of the transmission or reflection coefficient of a frequency-selective surface (FSS) to modulate electromagnetic (EM) waves, and achieves polarization manipulation which rotates the polarization of the wave upon reflection. These techniques can be used as countermeasures to Radar detection. A prototype of a switchable polarization-rotating FSS is designed, which can switch between co-polarized and cross-polarized reflection, and an EM wave modulation scheme is planned using a periodic signal to switch the polarization state of the FSS. The prototype's response was measured through experiments.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Francesco Alessio Dicandia, Simone Genovesi
Summary: This paper presents a novel design strategy for a transmission-type polarization rotator based on the characteristic modes (CMs) theory. Design guidelines are provided for exciting two current modes on a frequency selective surface (FSS) to achieve polarization rotation. The proposed design exhibits remarkable performance, including polarization insensitivity and compactness, and has been validated through measurements on a prototype.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Yi-Hao Ma, Da-Wei Wang, Yufeng Yu, Wen-Sheng Zhao
Summary: A design approach for dual-passband frequency-selective surface (FSS) with independent tunability is proposed. The principle of the design approach based on an equivalent circuit model is elaborated, and it is demonstrated that the construction of FSS unit cell with two independently controlled transmission poles is crucial. Referencing the proposed approach, a varactor-based polarization-insensitive dual-passband FSS with independent tunability is demonstrated experimentally.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Astronomy & Astrophysics
B. S. da Silva, A. L. P. S. Campos, M. E. T. Sousa, M. W. B. Silva, H. D. Andrade
Summary: This study presents an analysis technique for complementary frequency selective surfaces (CFSS) that combines the equivalent circuit method with the ABCD matrix. By modeling and simulating geometries such as circular rings, the research proposes an alternative optimization method to commercial software, showcasing lower computational effort and optimization time.
Article
Chemistry, Multidisciplinary
Junyan Zheng, Xin He, Paul Beckett, Xinjie Sun, Zixin Cai, Wenyi Zhang, Xu Liu, Xiang Hao
Summary: Dichroic circular polarizers (DCPs) and metasurface-based circular polarizers both have their own advantages and disadvantages. However, the plasmonic DCP structure proposed in this paper operates in the visible range with high circular dichroism transmission and maximum transmission efficiency, and is less sensitive to the angle of incidence.
Article
Engineering, Electrical & Electronic
Andreas Ericsson, Daniel Sjoberg, Giampiero Gerini, Cecilia Cappellin, Frank Jensen, Peter Balling, Nelson J. G. Fonseca, Peter de Maagt
Summary: An antenna system using CPSS was proposed to achieve CP equivalent to LP reflectors. The CPSS characteristics were computed through full-wave simulations and reflector surface shapes were optimized in TICRA POS software. Experimental results highlighted challenges in producing electrically large multilayer curved surfaces.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Muhammet Hilmi Nisanci, Francesco de Paulis
Summary: This study introduces a bendable frequency selective surface (FSS) based on carbon fibers for mechanical flexibility, with a band-stop frequency response. The design and manufacturing process highlight the advantages of the FSS in terms of costs, ease of design, and suitability for applications on parabolic reflectors and curved radomes.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Jin-Ming Xie, Bo Li, Lei Zhu
Summary: This article proposes a class of low-profile dual-band circular polarizers based on aperture-coupled patch resonators (ACPRs) to achieve versatile linear-to-circular polarization conversions. By designing specific transmission properties, the vertical and horizontal polarized transmitted waves of two independent ACPRs subelements can be achieved. With the introduction of versatile phase differences, multi-band LP-to-CP polarization conversions can be achieved. Experimental results demonstrate that the proposed structure has advantages of ultrathin profile, low axial ratio, and flexible designs in LP-to-CP conversions and frequency band ratios.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Tao Qin, Xian Qi Lin, Yao Yao, Yong Liu, Hao Liu, Peng Hao, Peng Mei
Summary: A new efficient synthesis method of angular selective surfaces (ASSs) based on the accurate equivalent circuit model is proposed in this paper. The angular dispersion of different components under oblique incidence is modeled by virtual lumped elements in the angular domain. The processes of obtaining the equivalent circuit for substrates, electrically small grids and patch arrays are presented in detail. The synthesized circuits are simple and accurate. Full-wave simulations are carried out to obtain the angular dispersion of different structures, and the calculated results are in good agreement with those of the equivalent circuit. A third-order ASS with bandpass response and a second-order ASS with a tunable bandwidth are given as design examples. The implemented second-order ASS shows the 0.33 to 0.52 tunable bandwidth in the angular domain. The transmission loss is better than 1.2 dB when the incidence angle is 65 degrees-77 degrees. The simulation results and calculated results are in good agreement with the measured results.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Article
Engineering, Electrical & Electronic
Ye Han, Shaowei Liao, Xin Xiu, Bo Li, Yumei Chang, Quan Xue, Wenquan Che
Summary: Novel designs of paper-based bandstop frequency-selective surfaces (FSSs) are presented in this article. The characteristics of the paper-based honeycomb structure are investigated first. One folded dipole resonator with first-order bandstop response is analyzed and further printed on the sidewalls of the honeycomb structure accordingly. A second-order response with two cascade FSSs is proposed with controllable bandwidth by the coupling coefficient of the resonators with the aid of the equivalent circuit model. Two paper-based FSS samples were fabricated and measured to demonstrate the validity of the proposed design strategies. Benefiting from the merits of lightweight and strong mechanical properties, the proposed paper-based FSS is a potential candidate for application in radar systems and aircraft.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Parinaz Naseri, Sean Hum
Summary: This article introduces a machine learning-based approach to automate the design of dual- and triple-layer metasurfaces, solving the difficulties encountered in traditional synthesis methods. This method allows for the synthesis of thin structures with specific scattering properties, applied in various metasurface applications.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Engineering, Electrical & Electronic
Gengyu Xu, George Eleftheriades, Sean Victor Hum
Summary: An accurate equivalent circuit model (ECM) for general multiwire multiorder printed circuit board (PCB) metagratings (MGs) is developed, with effective impedances of grating wires modeled as lumped loads. Numerous propagating Floquet harmonics are modeled as circuit ports, and a set of required scattering parameters for the ECM is derived based on desired field transformation for the MG. Optimizing equivalent lumped loads allows encoding multiple functions into a single device, enabling the design and investigation of angle-multiplexed multifunctional MGs.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Construction & Building Technology
Amir Ali Shahmansouri, Maziar Yazdani, Mehdi Hosseini, Habib Akbarzadeh Bengar, Hamid Farrokh Ghatte
Summary: The study demonstrates the potential of using artificial neural networks to predict the compressive strength and electrical resistivity of natural zeolitic concrete, significantly speeding up the process and improving accuracy. Experimental results from 324 different designs of natural zeolitic concrete specimens validate the accuracy and reliability of the model. This has important implications for cost reduction and time saving.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Electrical & Electronic
Reza Gholami, Parinaz Nasen, Piero Triverio, Sean Victor Hum
Summary: This article presents a generalized macromodeling approach to simulate complex electromagnetic surfaces, generating macromodels of unit cells by applying the equivalence principle. A new method is proposed to ensure the continuity of surface currents, with accuracy validated through comparisons with commercial solvers for different EM surfaces.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Engineering, Electrical & Electronic
Stewart Pearson, Sean Victor Hum
Summary: This article introduces a new optimization scheme for determining surface parameters to satisfy far-field constraints such as beam level, sidelobe level, and null locations. Through this optimization scheme, multicriteria pattern forming, extreme angle small surface refraction, and Chebyshev-like beamforming can be achieved.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Chemistry, Multidisciplinary
Mohammad Hossein Fekri, Samaneh Isanejad Mohamareh, Mehdi Hosseini, Maryam Razavi Mehr
Summary: Magnetic activated carbon was studied for the removal of antibiotic cefazolin from aqueous solutions and showed excellent antibacterial properties. By optimizing process conditions and analyzing the structure and adsorption behavior of the nanocomposite, it was found that the magnetically activated carbon could efficiently remove cefazolin from aqueous solution and exhibited good adsorption and antibacterial properties.
Article
Engineering, Electrical & Electronic
Parinaz Naseri, Stewart Pearson, Zhengzheng Wang, Sean Hum
Summary: This article proposes an efficient approach for the design of electromagnetic metasurfaces based on far-field constraints. The approach allows the designer to input high-level constraints and returns a design that satisfies these constraints. The method utilizes optimization and machine-learning techniques to determine the required surface parameters. Two examples are provided to demonstrate the effectiveness of the approach.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Article
Multidisciplinary Sciences
Parinaz Naseri, George Goussetis, Nelson J. G. Fonseca, Sean Hum
Summary: This paper proposes a data-driven approach integrated with a generative adversarial network for the design of electromagnetic linear-to-circular polarization converters. The method successfully synthesizes dual-band and triple-band reflective polarizers with stable performance and validates their feasibility and performance through experiments.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Electrical & Electronic
Elham Baladi, Gursimran Singh Sethi, Herve Legay, Sean Victor Hum
Summary: This work presents a low-profile center-fed leaky-wave antenna (LWA) that combines the full-space beam-scanning capabilities of transmitarrays and the low-profile nature of LWAs. A true-time-delay (TTD) phase-shifting mechanism is used to achieve a phase range of more than 540°. The proposed antenna consists of a 2564-element array that generates a pencil beam that can be steered to arbitrary angles.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Engineering, Electrical & Electronic
Beichen Duan, Erin R. Bobicki, Sean Victor Hum
Summary: This study investigates the potential application of microwave imaging in ore sorting systems and demonstrates its feasibility in separating valuable minerals or metals from ores.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Parinaz Naseri, George Goussetis, Nelson J. G. Fonseca, Sean Hum
Summary: This paper utilizes a machine-learning technique called generative adversarial network (GAN) to explore and exploit the solution space of reflective linear-to-circular polarization (LP-to-CP) converters. By optimizing the shape of the polarizing element, the proposed designs achieve superior performance in terms of overlapping axial ratio bandwidth for normal and oblique incidence of 30 degrees compared to previously studied designs.
2022 16TH EUROPEAN CONFERENCE ON ANTENNAS AND PROPAGATION (EUCAP)
(2022)
Article
Engineering, Electrical & Electronic
Gengyu Xu, George V. Eleftheriades, Sean Victor Hum
Summary: This paper presents a simple reconfigurable leaky-wave antenna (LWA) and an efficient optimization procedure for shaping its radiation pattern. The antenna is capable of meeting various requirements, such as wide-angle continuous beam-scanning and strong side lobe suppression. Importantly, it can adaptively tune the antenna input impedance to match the source without the need for a complicated matching network.
IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION
(2022)
Proceedings Paper
Geography, Physical
Mehdi Hosseini, Inbal Becker-Reshef, Ritvik Sahajpal, Pedro Lafluf, Guillermo Leale, Estefania Puricelli, Sergii Skakun, Heather McNairn
Summary: This study evaluated the potential of using Sentinel-1 dual-polarimetric data to forecast soybean yields at a field scale in central Argentina. By extracting polarimetric features and training an Artificial Neural Network (ANN) model, along with an innovative iterative retrieval method, the accuracy of soybean yield prediction was improved.
XXIV ISPRS CONGRESS: IMAGING TODAY, FORESEEING TOMORROW, COMMISSION III
(2022)
Article
Engineering, Electrical & Electronic
Stewart Pearson, Parinaz Naseri, Sean V. Hum
Summary: Electromagnetic metasurfaces have attracted attention due to their low profile and advantageous applications, but the design process is challenging and requires macroscopic and microscopic design steps. Through iterative optimization and machine learning surrogate models, successful realization of surface properties with far-field patterns compliant with constraints has been achieved.
IEEE OPEN JOURNAL OF ANTENNAS AND PROPAGATION
(2022)
Article
Computer Science, Information Systems
Gengyu Xu, Vasileios G. Ataloglou, Sean Victor Hum, George Eleftheriades
Summary: This study presents an end-to-end design of compact and low-loss metasurface antennas with integrated feeds. The antennas are implemented with a single-layered reactive impedance metasurface on top of a grounded dielectric substrate, and are fed by embedded sources. An accurate model is developed for rapid optimization of the wire impedances, leading to desired radiation characteristics and extreme field transformations. The design framework also includes feasibility-related constraints for enhanced power efficiency and bandwidth. The study demonstrates the capabilities of the design framework through the realization of wide-angle beamforming and multi-input, multi-output antennas with high aperture efficiency.
