Sökning: "FDTD"

Visar resultat 6 - 10 av 47 avhandlingar innehållade ordet FDTD.

1. 6. 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

3. 7. Radio Frequency Systems for NMR Imaging: Coil Development and Studies of Non-Thermal Biological Effects

   Författare :Lars Malmgren; Lunds universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; anechoic chamber; TEM transmission cells; FDTD; circularly polarized electromagnetic fields; reduced coupling; noise matching; matching networks; low noise amplifiers; upper thoracic spine; surface coils; Nuclear magnetic resonance; magnetic resonance imaging; non-thermal biological effects; blood-brain barrier; Electronics; Elektronik;

   Sammanfattning : This thesis concerns both design and optimization of NMR imaging systems and studies on non-thermal biological effects of electromagnetic fields. These two research fields are linked together by the fact that humans are subject to static and pulsed magnetic fields as well as to magnetic radio frequency fields (RF) during an NMR imaging investigation. LÄS MER

4. 8. System-in-a-Package on Low-Cost Liquid Crystal Polymer Substrate

   Författare :Gang Zou; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; FDTD; integrated passive components; ACA; liquid crystal polymer; FEM; flip-chip; RF; anisotropic conductive adhesive; system-in-a-package; system-on-a-package;

   Sammanfattning : System-in-a-Package (SiP) is one of the most advanced approaches to meet the requirements for future high-density electronics packaging. In this thesis, a 3D system-in-a-package concept with embedded active and passive components is proposed, where a liquid crystal polymer (LCP) was used as the base substrate. LÄS MER

5. 9. Moment Method Analysis of Antennas on Cylindrical Structures by Using G2DMULT and Design of Hat Fed Reflector Antennas

   Författare :Jian Yang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; G2DMULT; reflector antenna; paraboloid; dipole; base station antenna; screw heads; vertex plate; self impedance; G1DMULT; ring-shaped phase center; radiation efficiency; FDTD; cylindrical structures; V2D; ring-focus; moment method;

   Sammanfattning : This thesis deals with two aspects of research interest: moment method analysis of antennas on cylindrical structures by using G2DMULT, and design of hat fed reflector antennas. Both of them are two-dimensional (2D) structure problems, one being cylindrical and the other rotationally symmetric. LÄS MER

7. 10. Microwave tomography

   Författare :Andreas Fhager; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inverse algorithms; microwave tomography; image reconstruction; FDTD; inverse Maxwell problem; mammography;

   Sammanfattning : Microwave tomography for non-destructive detection of internaldielectric properties has received increasing interest during the lastdecades. Several application areas are under research, includingapplications in geoscience, biomedical applications, safety andsecurity etc. LÄS MER