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View article: Joint Signal and Topology Optimization for Maximum Instantaneous Field Intensity
Joint Signal and Topology Optimization for Maximum Instantaneous Field Intensity Open
This paper introduces a computational approach to identify performance constraints in the time-domain, offering a way to design systems in pulse operation. This work presents a comprehensive application of convex optimization to determine …
View article: Optimization of Embedded Element Patterns of Reactively Loaded Antenna Arrays
Optimization of Embedded Element Patterns of Reactively Loaded Antenna Arrays Open
View article: Comparison of Optimization Approaches to Design Reactively Loaded Antenna Arrays
Comparison of Optimization Approaches to Design Reactively Loaded Antenna Arrays Open
Publisher Copyright: © 2025 European Association on Antennas and Propagation.
View article: Towards Manufacturing-Friendly Shapes in Discrete Topology Optimization
Towards Manufacturing-Friendly Shapes in Discrete Topology Optimization Open
This paper deals with shape irregularity issues in discrete topology optimization algorithms whereby the design is created using the automated distribution of material in the design region. Graph theory is employed to derive appropriate re…
View article: Density-Based Topology Optimization for Characteristic Modes Manipulation
Density-Based Topology Optimization for Characteristic Modes Manipulation Open
A density-based topology optimization framework is developed to manipulate characteristic modes of conducting surfaces. The adjoint sensitivity analysis provides an efficient computation of the material gradient utilized by the local optim…
View article: Characteristic Mode Analysis of Acoustic Scatterers
Characteristic Mode Analysis of Acoustic Scatterers Open
The explicit connection between the transition matrix and boundary element method integral operators is formulated. This enables the calculation of characteristic modes via eigenvalue problems involving either set of operators, leading to …
View article: Optimization of Embedded Element Patterns of Reactively Loaded Antenna Arrays
Optimization of Embedded Element Patterns of Reactively Loaded Antenna Arrays Open
This paper introduces a framework for synthesizing reactively loaded antennas and antenna arrays. The framework comprises two main components: computing the fundamental bound using the semi-definite relaxation and finding a realizable solu…
View article: Design Recommendations for Minimal Antenna Mutual Coupling Using Current Optimization
Design Recommendations for Minimal Antenna Mutual Coupling Using Current Optimization Open
This work addresses a first attempt at using current density optimization algorithms to gain insight into the relation between maximum achievable gain in a given direction and the mutual coupling to another antenna nearby. The methodology …
View article: Theory and Computation of Substructure Characteristic Modes
Theory and Computation of Substructure Characteristic Modes Open
The problem of substructure characteristic modes is developed using a scattering matrix-based formulation, generalizing subregion characteristic mode decomposition to arbitrary computational tools. It is shown that the modes of the scatter…
View article: Maximum Radiation Efficiency of Arbitrarily Shaped Implantable Antennas
Maximum Radiation Efficiency of Arbitrarily Shaped Implantable Antennas Open
Performance limitations for implanted antennas, taking radiation efficiency as the metric, are presented. The performance limitations use a convex optimization procedure with the current density inside the implant acting as its degree of f…
View article: Generalized Friis Transmission Formula Using Active Antenna Available Power and Unnamed Power Gain
Generalized Friis Transmission Formula Using Active Antenna Available Power and Unnamed Power Gain Open
We use the concept of active antenna available power to derive a generalization of the Friis transmission formula for multiport antenna systems. With beamformer weights chosen such that the array patterns are the same when transmitting and…
View article: Implementing Two Generalizations of the Friis Transmission Formula
Implementing Two Generalizations of the Friis Transmission Formula Open
<p>Two generalizations of the Friis transmission formula are based on the concept of unnamed power gain, defined as the ratio of the available power at the port(s) of one or more receiving antennas to the average power received by th…
View article: Characteristic Modes of Nonreciprocal Structures
Characteristic Modes of Nonreciprocal Structures Open
The scattering formulation of characteristic mode decomposition is utilized to extend modal analysis to lossless scatterers breaking time-reversal symmetry. This enables characteristic modes analysis on devices containing gyrotropic or mov…
View article: Characteristic Modes of Frequency-Selective Surfaces and Metasurfaces from S-parameter Data
Characteristic Modes of Frequency-Selective Surfaces and Metasurfaces from S-parameter Data Open
Characteristic modes of arbitrary two-dimensional periodic systems are analyzed using scattering parameter data. This approach bypasses the need for periodic integral equations and allows for characteristic modes to be computed from generi…
View article: Maximum Radiation Efficiency of Arbitrarily-Shaped Implantable Antennas
Maximum Radiation Efficiency of Arbitrarily-Shaped Implantable Antennas Open
Performance limitations for implanted antennas, taking radiation efficiency as the metric, are presented. The performance limitations use a convex optimization procedure with the current density inside the implant acting as its degree of f…
View article: Trade-off Between Optimal Efficiency and Envelope Correlation Coefficient for Antenna Clusters
Trade-off Between Optimal Efficiency and Envelope Correlation Coefficient for Antenna Clusters Open
This paper introduces a theory for assessing and optimizing the multiple-input-multiple-output performance of multi-port cluster antennas in terms of efficiency, channel correlation, and power distribution. A method based on a convex optim…
View article: Maximum Radiation Efficiency of an Implantable Antenna: The Role of High-Order Modes
Maximum Radiation Efficiency of an Implantable Antenna: The Role of High-Order Modes Open
A combination of two numerical techniques of computational electromagnetics, namely, method of moments and vector spherical wave expansion, is used to show performance limitations on the radiation efficiency of implantable antennas and to …
View article: Density-Based Topology Optimization in Method of Moments: Q-factor Minimization
Density-Based Topology Optimization in Method of Moments: Q-factor Minimization Open
Classical gradient-based density topology optimization is adapted for method-of-moments numerical modeling to design a conductor-based system attaining the minimal antenna Q-factor evaluated via an energy stored operator. Standard topology…
View article: The Upper Bound on Antenna Gain and Its Feasibility as a Sum of Characteristic Gains
The Upper Bound on Antenna Gain and Its Feasibility as a Sum of Characteristic Gains Open
The upper bound on antenna gain is expressed as a sum of lossy characteristic modes, specifically, as a sum of characteristic far fields squared. The procedure combines the favorable properties of Harrington's classical approach to maximum…
View article: Scattering Matrix Formulation for Substructure Characteristic Mode Analysis
Scattering Matrix Formulation for Substructure Characteristic Mode Analysis Open
Scattering based formulation of substructure CM
View article: Upper bounds on focusing efficiency
Upper bounds on focusing efficiency Open
Upper bounds on the focusing efficiency of aperture fields and lens systems are formulated using integral equation representations of Maxwell’s equations and Lagrangian duality. Two forms of focusing efficiency are considered based on lens…
View article: Unified Theory of Characteristic Modes—Part I: Fundamentals
Unified Theory of Characteristic Modes—Part I: Fundamentals Open
A unification of characteristic mode decomposition for all method-of-moment\nformulations of field integral equations describing free-space scattering is\nderived. The work is based on an algebraic link between impedance and\ntransition ma…
View article: Unified Theory of Characteristic Modes—Part II: Tracking, Losses, and FEM Evaluation
Unified Theory of Characteristic Modes—Part II: Tracking, Losses, and FEM Evaluation Open
This is the second component of a two-part paper dealing with a unification\nof characteristic mode decomposition. This second part addresses modal tracking\nand losses and presents several numerical examples for both surface- and\nvolume-…
View article: Iterative Calculation of Characteristic Modes Using Arbitrary Full-wave Solvers
Iterative Calculation of Characteristic Modes Using Arbitrary Full-wave Solvers Open
An iterative algorithm is adopted to construct approximate representations of matrices describing the scattering properties of arbitrary objects. The method is based on the implicit evaluation of scattering responses from iteratively gener…
View article: Performance Bounds of Magnetic Traps for Neutral Particles
Performance Bounds of Magnetic Traps for Neutral Particles Open
Knowledge of the fundamental limitations on a magnetic trap for neutral particles is of paramount interest to designers as it allows for the rapid assessment of the feasibility of specific trap requirements or the quality of a given design…
View article: Characteristic Mode Decomposition Using the Scattering Dyadic in Arbitrary Full-Wave Solvers
Characteristic Mode Decomposition Using the Scattering Dyadic in Arbitrary Full-Wave Solvers Open
Characteristic modes are formulated using the scattering dyadic, which maps incident plane waves to scattered far fields generated by an object of arbitrary material composition. Numerical construction of the scattering dyadic using arbitr…
View article: Method of Moments and T-Matrix Hybrid
Method of Moments and T-Matrix Hybrid Open
Hybrid computational schemes combining the advantages of a method of moments formulation of a field integral equation and T-matrix method are developed in this paper. The hybrid methods are particularly efficient when describing the intera…
View article: Memetic Scheme for Inverse Design Using an Exact Reanalysis of Method-of-Moments Models -- Part 2: Examples and Properties
Memetic Scheme for Inverse Design Using an Exact Reanalysis of Method-of-Moments Models -- Part 2: Examples and Properties Open
Memetics for shape synthesis, introduced in Part 1, is examined on antenna design examples. It combines local and global techniques to accelerate convergence and to maintain robustness. Method-of-moments matrices are used to evaluate objec…
View article: Optimal Inverse Design Based on Memetic Algorithms -- Part 2: Examples and Properties
Optimal Inverse Design Based on Memetic Algorithms -- Part 2: Examples and Properties Open
Optimal inverse design, including topology optimization and evaluation of fundamental bounds on performance, which was introduced in Part~1, is applied to various antenna design problems. A memetic scheme for topology optimization combines…
View article: Memetic Scheme for Inverse Design Using Exact Reanalysis of Method-of-Moments Models -- Part 1: Theory and Implementation
Memetic Scheme for Inverse Design Using Exact Reanalysis of Method-of-Moments Models -- Part 1: Theory and Implementation Open
A novel inverse design framework over a fixed discretization grid using method of moments for the shape optimization of radiation devices is proposed. The formulation is discrete and solves the original combinatorial problem. Fixed discret…