Sökning: "FDTD methods"

Visar resultat 1 - 5 av 16 avhandlingar innehållade orden FDTD methods.

1. 1. Direct and Inverse Methods for Waveguides and Scattering Problems in the Time Domain

   Författare :Erik Abenius; Per Lötstedt; Mats Gustafsson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Maxwell s equations; time-domain; FDTD; finite-element; hybrid; thin sheet; waveguide; PML; inverse scattering; adjoint; gradient-based; minimization; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : Numerical simulation is an important tool in understanding the electromagnetic field and how it interacts with the environment. Different topics for time-domain finite-difference (FDTD) and finite-element (FETD) methods for Maxwell's equations are treated in this thesis. LÄS MER

3. 2. Computation of EMC Properties of Slots and Printed Circuit Boards

   Författare :Jan Carlsson; RISE; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; corrugations; crosstalk; FDTD; spectral domain; EFIE; chokes; Finite Difference Method; printed circuit board; transmission line network; EMC analysis; PCB; transmission line theory; radiated emission; Method of moments; MM; MoM; electric field integral equation; soft and hard surfaces; slot; radiated susceptibility;

   Sammanfattning : This thesis deals with the numerical solution of electromagnetic compatibility (EMC) problems for electronic systems, such as radiated emission, susceptibility and crosstalk on printed circuit boards and transmission through slots. The analysis of printed circuit boards is done by using an electric field integral equation (EFIE) expressed in the frequency domain, which is solved by using the method of moments. LÄS MER

4. 3. A comprehensive study of resistor-loaded planar dipole antennas for ground penetrating radar applications

   Författare :Disala Uduwawala; Martin Norgren; Olav Breinbjerg; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ground penetrating radar; buried object detection; dipole antennas; FDTD methods; broadband properties; baluns; simulation; optimal design; lossy media; dispersive media; clutter.; Electrical engineering; Elektroteknik;

   Sammanfattning : Ground penetrating radar (GPR) systems are increasingly being used for the detection and location of buried objects within the upper regions of the earth’s surface. The antenna is the most critical component of such a system. LÄS MER

5. 4. Modified Stencils for Boundaries and Subgrid Scales in the Finite-Difference Time-Domain Method

   Författare :Jon Häggblad; Björn Engquist; Olof Runborg; Björn Sjögreen; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; FDTD; Yee; Staircasing;

   Sammanfattning : This thesis centers on modified stencils for the Finite-Difference Time-Domain method (FDTD), or Yee scheme, when modelling curved boundaries, obstacles and holes smaller than the discretization length.  The goal is to increase the accuracy while keeping the structure of the standard method, enabling improvements to existing implementations with minimal effort. LÄS MER

7. 5. Analysis of Resistor-Loaded Bow-Tie Antennas for Ground Penetrating Radar Applications

   Författare :Disala Uduwawala; KTH; []
   Nyckelord :Ground penetrating radar; Buried object detection; Simulation; Radar antennas; Radar signal processing; FDTD methods; Optimal design; Lossy media; Dispersive media; Clutter; Polarization;

   Sammanfattning : Ground penetrating radar (GPR) systems are increasinglybeing used for the detection and location of buried objectswithin the upper regions of the earth's surface. Numericalsimulation of such systems plays an important role in thedevelopment of GPR hardware and signal processingtechniques. LÄS MER