Guest Editorial Sideris, Constantine
IEEE transactions on microwave theory and techniques,
2024-Aug., Volume:
72, Issue:
8
Journal Article
Peer reviewed
I am delighted to introduce this Mini-Special Issue of the IEEE Transactions on Microwave Theory and Techniques (TMTT), which showcases selected papers from the International Conference on Numerical ...Electromagnetics, Multiphysics Modeling and Optimization (NEMO 2023). The NEMO 2023 took place on June 28-30, 2023 at the historic Fort Garry Hotel in the heart of Winnipeg, MB, Canada. NEMO is an annual international event founded in 2014 and has become a popular venue for exchanging novel ideas in computational and applied electromagnetics, multiphysics simulations, and optimization methods. Alternating between North America, Asia, and Europe, the conference brings together leading experts from academia and industry within the IEEE Microwave Theory and Techniques Society (IEEE MTT-S) and beyond. In particular, broad participation was achieved this year due to the availability of both online and in-person formats for attendance. The participants of the NEMO 2023 had the opportunity to attend the technical sessions and social events and to establish closer personal contacts. The NEMO 2023 was sponsored by the Price Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada, and industry partners Xpeedic, Ansys, CEMWorks, and Sonnet Software.
Guest Editorial Sideris, Constantine
IEEE transactions on microwave theory and techniques,
01/2024, Volume:
72, Issue:
8
Journal Article
Peer reviewed
I am delighted to introduce this Mini-Special Issue of the IEEE Transactions on Microwave Theory and Techniques (TMTT), which showcases selected papers from the International Conference on Numerical ...Electromagnetics, Multiphysics Modeling and Optimization (NEMO 2023). The NEMO 2023 took place on June 28–30, 2023 at the historic Fort Garry Hotel in the heart of Winnipeg, MB, Canada. NEMO is an annual international event founded in 2014 and has become a popular venue for exchanging novel ideas in computational and applied electromagnetics, multiphysics simulations, and optimization methods. Alternating between North America, Asia, and Europe, the conference brings together leading experts from academia and industry within the IEEE Microwave Theory and Techniques Society (IEEE MTT-S) and beyond. In particular, broad participation was achieved this year due to the availability of both online and in-person formats for attendance. The participants of the NEMO 2023 had the opportunity to attend the technical sessions and social events and to establish closer personal contacts. The NEMO 2023 was sponsored by the Price Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada, and industry partners Xpeedic, Ansys, CEMWorks, and Sonnet Software.
Abstract
Silicon photonics is an emerging technology which, enabling nanoscale manipulation of light on chips, impacts areas as diverse as communications, computing, and sensing. Wavelength division ...multiplexing is commonly used to maximize throughput over a single optical channel by modulating multiple data streams on different wavelengths concurrently. Traditionally, wavelength (de)multiplexers are implemented as monolithic devices, separate from the grating coupler, used to couple light into the chip. This paper describes the design and measurement of a grating coupler demultiplexer—a single device which combines both light coupling and demultiplexing capabilities. The device was designed by means of a custom inverse design algorithm which leverages boundary integral Maxwell solvers of extremely rapid convergence as the mesh is refined. To the best of our knowledge, the fabricated device enjoys the lowest insertion loss reported for grating demultiplexers, small size, high splitting ratio, and low coupling-efficiency imbalance between ports, while meeting the fabricability constraints of a standard UV lithography process.
This article introduces a concurrent dual-mode directional coupler design for substrate-integrated waveguides (SIWs), which can independently excite the fundamental and second higher order modes ...(TE10 and TE20). We utilize this coupler to demonstrate the possibility of creating a multimode, multidrop communication link, which exploits mode orthogonality, enhancing the total channel capacity. To the best of our knowledge, this is the first realization of a concurrent multimode directional coupler in SIW technology. The coupling structure consists of four coupling nodes. Each one has two ports (one per mode), resulting in a total of eight ports. The coupling factors for the TE10 and TE20 modes are −10 dB each, allowing ten drop points along the SIW in a multidrop SIW link. The structure was fabricated using a Rogers Duroid 5880 substrate, achieving a 10-dB return loss (RL) bandwidth (BW) of more than 3.2 GHz (11.8-15 GHz) and 3.5 GHz (10-13.5 GHz) for the fundamental and second modes, respectively, corresponding to 1.7 GHz of BW for concurrent mode division multiplexing. The measured isolation between the two channels is more than 30 dB across the entire band, and the insertion loss (IL) is 1.0 and 1.5 dB, respectively. The measurement results agree well with electromagnetic simulations.
Magnetic spectroscopy allows for characterization of the magnetic susceptibility of magnetic beads across a broad frequency range. This enables differentiation and quantification of multiple beads of ...varying types concurrently present in the active volume of a sensor's surface. A magnetic spectrometer can be used for multi-probe tagging and identification akin to multi-color fluorescent bio-sensing. We propose a new sensing methodology to perform magnetic spectroscopy and analyze various important design parameters such as SNR and gain uniformity. We present a proof-of-concept design of a fully integrated CMOS magnetic spectrometer that can detect, quantify, and characterize magnetic materials in the 1.1 GHz to 3.3 GHz frequency range, where we demonstrate magnetic multiplexing capability using a mixture of two different kinds of magnetic beads. The sensor consumes less than 2 mW of DC power within the whole frequency range, requires no external biasing magnetic fields, is implemented in a standard CMOS process, and can be powered and operated completely from a USB interface. The magnetic spectrometer not only increases the throughput and multiplexing of biosensing experiments for a given sensor area, but also can enable additional applications, such as magnetic flow cytometry and signal-collocation assays of multiple probes.
This article introduces a high-order accurate surface integral equation (SIE) method for solving 3-D electromagnetic scattering for dielectric objects with uniaxially anisotropic permittivity ...tensors. The N-Müller formulation is leveraged, resulting in a second-kind integral formulation, and a finite-difference (FD)-based approach is used to deal with the strongly singular terms resulting from the dyadic Green's functions for uniaxially anisotropic media while maintaining the high-order accuracy of the discretization strategy. The integral operators are discretized via a Nyström-collocation approach, which represents the unknown surface densities in terms of Chebyshev polynomials on curvilinear quadrilateral surface patches. The convergence is investigated for various geometries, including a sphere, cube, a complicated non-uniform rational basis spline (NURBS) geometry imported from a 3-D computer-aided design (CAD) modeler software, and a nanophotonic silicon waveguide, and the results are compared against a commercial finite-element (FE) solver. To the best of our knowledge, this is the first demonstration of high-order accuracy for objects with uniaxially anisotropic materials using SIEs.
This paper introduces an efficient approach for solving the Electric Field Integral Equation (EFIE) with high-order accuracy by explicitly enforcing the continuity of the impressed current densities ...across boundaries of the surface patch discretization. The integral operator involved is discretized via a Nyström-collocation approach based on Chebyshev polynomial expansion within each patch and a closed quadrature rule is utilized such that the discretization points inside one patch coincide with those inside another patch on the shared boundary of those two patches. The continuity enforcement is achieved by constructing a mapping from those coinciding points to a vector containing unique discretization points used in the GMRES iterative solver. The proposed approach is applied to the scattering of several different geometries including a sphere, a cube, a NURBS model imported from CAD software, and a dipole structure and results are compared with the Magnetic Field Integral Equation (MFIE) and the EFIE without enforcing continuity to illustrate the effectiveness of the approach.
