Sökning: "adjoint-field problem"

Hittade 3 avhandlingar innehållade orden adjoint-field problem.

  1. 1. Topology optimization of antennas and waveguide transitions

    Författare :Emadeldeen Hassan; Martin Berggren; Daniel Noreland; Eddie Wadbro; Mats Gustafsson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Maxwell s equations; topology optimization; antennas; waveguide transition; finite-difference time-domain; gradient-based optimization; adjoint-field problem; microwave devices.; business data processing; administrativ databehandling;

    Sammanfattning : This thesis introduces a topology optimization approach to design, from scratch, efficient microwave devices, such as antennas and waveguide transitions. The design of these devices is formulated as a general optimization problem that aims to build the whole layout of the device in order to extremize a chosen objective function. LÄS MER

  3. 2. Shape and material optimization for antenna applications

    Författare :Per Jacobsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; explicit-implicit time stepping; sensitivity analysis; Nitsche s method; total scattering cross section; shape and material optimization; array antennas; finite element method;

    Sammanfattning : In this thesis, a gradient-based method for shape and material optimization fortwo antenna applications is presented: minimization of the active reflectioncoefficient for conformal array antennas; and minimization of the totalscattering cross section for cylindrical scatterers. The sensitivity of theobjective function with respect to changes of the shape and material of the geometry isexpressed in terms of the original field problem and an adjoint field problem. LÄS MER

  4. 3. Microwave Measurement Systems for Parameter Estimation and Classification

    Författare :JOHAN WINGES; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microcrystalline cellulose; parameter estimation; sensitivities; microwave measurements; finite element method; gradient-based optimization; permittivity;

    Sammanfattning : Microwave measurement systems are attractive for diagnostics and monitoring purposes in a number of important applications. For example, the strong interaction between microwaves and water make microwaves well-suited for moisture measurements. LÄS MER