This paper presents a survey of recent developments using Doppler radar sensor in searching and locating an alive person under debris or behind wall. Locating human detecting the vital signs such as breathing rate heartbeat microwave is non-invasive technique. Recently, many hardware structures, signal processing approaches, integrated systems have been introduced by researchers this field. The purpose to enhance accuracy signs' detection location reduce energy consumption. work concentrates...

This paper describes and rigorously validates single- multiple-layer models of microstrip conductor loss appropriate for high-accuracy application in electromagnetic analysis software. The are validated by comparison with measurement converged results. It is shown that some cases an extremely small cell size needed order to achieve convergence. Several effects make a significant contribution not modeled the classic square root frequency model investigated including dispersion current on side...

A finite-difference time-domain (FDTD) scattered-field formulation for dispersive chiral media is developed and presented in this paper. The FDTD based on the Z transform method models frequency-dependent nature of permittivity, permeability, chirality as well. permittivity permeability are assumed to follow Lorentz model while Condon model. three-dimensional electromagnetic applications. Results copolarization cross-polarization reflected transmitted waves from a slab due normal incidence...

Modifications in the measurement of complex permittivity are described, based on transmission and reflection coefficients a dielectric slab. The uses TRL two- port calibration to bring reference planes accurately sample surface. as function frequency is computed by minimizing difference between measured ideal scattering parameters. An alternative procedure for determining fractional linear data fitting Q- circle virtual short-circuit and/or open circuit data. In that case, must be multiple...

Various numerical techniques have been developed for modeling electromagnetic field propagation in various novel complex media. The validity of these is usually verified by comparison to the exact solutions canonical problems. Recently, research has focused on chiral media, a subclass materials known as bianisotropic materials, and order calculate interaction fields with objects. One problem plane-wave scattering from sphere. This work presents software package that displays saves calculated...

In this paper, finite difference frequency domain (FDFD) formulation has been developed for the analysis of electromagnetic wave interaction with chiral materials, and validity three dimensional scattering problems confirmed by comparing numerical results to exact or other solutions.The influences chirality on scattered field components are investigated.Numerical bistatic radar cross section (RCS) presented compared reference solutions it is found that proposed FDFD method shows good...

Abstract Electromagnetic band gap (EBG) structures have been used in many antenna designs to improve their performance. This paper investigates the performance of a dipole near edge ground plane, popular setup various wireless communication systems. To increase radiation efficiency, printed with semi-EBG plane is proposed. Both FDTD simulations and experimental results demonstrate validity this design.

This paper presents a hybrid technique, which combines the desirable features of two different numerical methods, finite difference frequency domain (FDFD) and method moments (MoM), to analyze large-scale electromagnetic problems. is done by dividing computational into smaller sub-regions solving each sub-region using appropriate method. Once analyzed, independently, an iterative approach takes place combine solutions obtain solution for complete domain. As result, considerable reduction in...

An iterative approach using the finite difference frequency domain method is presented in this paper order to solve problem of scattering from large three-dimensional electromagnetic scatterers. The idea multiregion technique introduced divide one computational into smaller subregions and each subregion separately. Then solutions are combined iteratively obtain a solution for complete domain. As result, considerable reduction computation time memory has been achieved.

An efficient finite-difference time-domain (FDTD) algorithm with a simple periodic boundary condition (PBC) is developed to analyze general structures arbitrary skewed grids. The easy implement and in both memory usage computation time. stability criterion of the angle independent therefore it suitable for implementing incidence close grazing as well normal incidence. validity this verified through several numerical examples such dipole Jerusalem cross frequency selective surfaces (FSS)...

A square loop antenna of circumference about one free-space wavelength displays an omnidirectional radiation pattern when its conductor is partitioned into five segments that are interconnected by four small capacitances. The optimization process for determining the capacitances values described in detail. required created overlapping on opposite sides substrate. far field resembles elementary magnetic dipole. At center frequency 956 MHz, measured maximum gain 2 dBi, and efficiency 94%.

Multiwalled carbon nanotube (MWCNT) composites are characterized within 8-10 GHz using a waveguide of square cross section. The complex permittivity is extracted and empirical expressions obtained as function frequency by minimizing the difference between measured theoretical values scattering parameters. Composites with CNT concentrations ranging from 0%-20% investigated. section allows for different orientations samples to test anisotropy MWCNT composites.

One of the methods to solve large electromagnetic problems is divide computational domain into smaller subregions and each subregion separately. Then solutions are combined obtain a solution for complete domain. In this paper, an iterative approach using finite difference frequency method presented that can be divided separated subregions.

This paper presents a novel electromagnetic optimization technique based on Taguchi method. Using the concept of orthogonal array (OA), method effectively reduces number tests required in an process. Although this has been successfully applied many fields such as chemical engineering, mechanical IC manufacture, power electronics etc., it is not well known to electromagnetics community, and only limited applications are available. The goal study introduce community demonstrate its great...

This paper introduces a novel electromagnetic optimization technique using Taguchi method. To illustrate this technique, linear antenna array is optimized to realize null control pattern and sector beam pattern. It found that method easy implement it converges the desired patterns quickly. good candidate for optimizing EM applications.

Finding a good preconditioner to solve given sparse linear system is often considered difficult but important task. One of the simplest ways defining perform an incomplete LU decomposition (ILU) original matrix. The ILU factorization be easy and inexpensive use. However, it fails provide solution generated from general three-dimensional problems with three unknowns. In this paper, modified proposed efficient for highly matrices, especially matrices constructed using finite-difference...

Finite-Difierence Time-Domain (FDTD) subgridding schemes can signiflcantly improve e-ciency of various electromagnetic circuit simulations. However, numerous sufier from issues associated with stability, e-ciency, and material traverse capability. These limit general applicability FDTD subgrid- ding to realistic problems. Herein, a robust nonuniform sub- gridding scheme is presented that overcomes those weaknesses. The improves simulation accuracy the aid greatly increased stability margin...

A novel time-domain adjoint sensitivity analysis (ASA) approach is proposed. Our finite-difference (FDTD)-based accelerates wideband calculations for high-frequency structures with nonlinear media. The introduced supports simulated problems current sources or incident field excitation. Using only one extra system simulation, the sensitivities of a general objective function/response are estimated respect to all design parameters. presented theory based on first-order Maxwell's equations...

In this work, an iterative approach using the finite difference frequency domain method is presented to solve problem of scattering from large-scale electromagnetic structures. The idea proposed divide one computational into smaller subregions and each subregion separately. Then solutions are combined iteratively obtain a solution for complete domain. As result, considerable reduction in computation time memory achieved. This procedure referred as multiregion (IMR) technique.

Recently, many numerical methods that are developed for the solution of electromagnetic problems have greatly beneflted from hardware accelerated scientiflc computing capability provided by graphics processing units (GPUs) and orders magnitude speed-up factors been reported. Among these methods, flnite-difierence frequency-domain (FDFD) method as well can be substantially utilizing an e-cient algorithm customized GPU computing. In this contribution, is presented treats iterative FDFD linear...