## A Hybrid EM/QM Framework Based on the ADHIE-FDTD Method for the Modeling of Nanowires

A new modeling formalism to compute the time-dependent behavior of combined electromagnetic (EM) and quantum mechanical (QM) systems is proposed. The method is geared towards highly multiscale geometries, which is vital for the future design of nanoelectronic devices. The advocated multiphysics modeling formalism leverages the alternating-direction hybrid implicit-explicit (ADHIE) finite-difference time-domain (FDTD) method for the […]

## A Robust Bayesian Optimization Framework for Microwave Circuit Design Under Uncertainty

In modern electronics, there are many inevitable uncertainties and variations of design parameters that have a profound effect on the performance of a device. These are, among others, induced by manufacturing tolerances, assembling inaccuracies, material diversities, machining errors, etc. This prompts a wide interests in enhanced optimization algorithms that take the effect of these uncertainty […]

## An efficient algorithm to determine the operational range of near-field on-body UHF RFID systems

A new algorithm is proposed, leveraging a 3D multipole expansions of the electromagnetic fields, to accurately determine the operational range of a radiative near-field on-body radio-frequency identification (RFID) system based on its far field radiation patterns, simulated or measured, under realistic deployment conditions. We illustrate the advocated method by an interrogating 866 MHz standard gain […]

## Accurate Characterization of Radiation from Interconnects on Interposer at mmWave Frequencies

An electromagnetic interference (EMI) assessment of mmWave interposers becomes increasingly important as the need for heterogeneous systems increases. However, the small size and complexity of these platforms make it more difficult to accurately measure them and, thus, a dedicated set-up to isolate the interposer’s emission is required. In this contribution, we first show experimentally that […]

## Uncertainty Quantification of Electromagnetic Devices, Circuits, and Systems

Profs. Paolo Manfredi and Dries Vande Ginste authored Chapter 2 (Polynomial Chaos Based Uncertainty Quantification in Electrical Engineering: Theory) and Chapter 3 (Polynomial Chaos Based Uncertainty Quantification in Electrical Engineering: Applications) of the book Uncertainty Quantification of Electromagnetic Devices, Circuits, and Systems, edited by Prof. Sourajeet Roy and published by the Institution of Engineering and […]

## Efficient modeling of on-body passive UHF RFID systems in the radiative near-field

A novel method is presented to accurately determine the operational range of an on-body, passive ultra-high-frequency (UHF) radio-frequency identification (RFID) system operating in the radiative near-field, based on its far-field radiation patterns. To this end, an efficient algorithm based on 3-D multipole expansion of the electromagnetic fields is formulated. By combining the new operator with […]

## A 2-D differential surface admittance operator for combined magnetic and dielectric contrast

In this paper, we present a novel technique to accurately model scattering phenomena at two-dimensional circular and rectangular structures consisting of arbitrary homogeneous materials, including magnetic media in particular. The proposed formalism utilizes a differential surface admittance operator, which invokes a single source equivalence theorem to replace the inside material by its surrounding medium, while […]

## An alternating-direction hybrid implicit-explicit finite-difference time-domain method for the Schrödinger equation

This paper proposes a novel hybrid FDTD method for solving the time-dependent Schrödinger equation, which is fundamental for modeling materials and designing nanoscale devices. The wave function is propagated on nonuniform grids by applying explicit updates in part of the grid and implicit updates elsewhere. The latter are based on the Alternating-Direction Implicit (ADI) scheme […]

## Comparison of two novel integral equation approaches for lossy conductor modeling

In this paper, we take a closer look at two novel boundary integral equation methods that are ideally suitable for modeling good but lossy conductors. The first method leverages the Calderón identities to precondition the homogeneous Poincaré-Steklov operator for high dielectric contrast materials. The second technique constructs an alternative formulation of the Poincaré-Steklov operator based […]

## Uncertainty quantification of charge transfer through a nanowire resonant-tunneling diode with an ADHIE-FDTD method

The influence of barrier thickness variability on the charge transfer characteristics of an InP/InAs/InP nanowire resonant-tunneling diode is studied. The transmission probability through the diode is calculated by solving the time-dependent effective-mass Schrödinger equation with the Alternating-Direction Hybrid Implicit-Explicit (ADHIE) Finite-Difference Time-Domain (FDTD) method. This recently developed method is tailored towards multiscale problems and thus […]