Sökning: "frequency selective structures"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden frequency selective structures.

  1. 1. Thick Frequency Selective Structures

    Författare :Björn Widenberg; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustics; Elektromagnetism; optik; akustik; optics; Electromagnetism; Energy Saving Window; Radome; Finite Elemente Method; Frequency Selective Structure; Mode Matching Technique;

    Sammanfattning : This thesis presents a new method that can handle a general thick Frequency Selective Structure (FSS), that consists of an arbitrary number of aperture layers and dielectric layers. The method is based on the Mode Matching Technique (MMT) and the finite element method (FEM). The thesis consists of a General Introduction and five scientific papers. LÄS MER

  2. 2. Frequency Selective Cold-Electron Bolometer Arrays

    Författare :Sumedh Mahashabde; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mm-wave detectors; Cold-Electron Bolometer; Frequency Selective Surface; Focal Plane array; OLIMPO; LSPE;

    Sammanfattning : This work presents the integration of the Cold-Electron Bolometer (CEB) in Frequency Selective Surface (FSS) based arrays targeting balloon-borne telescope missions with high incident power requirements (typically tens of pW). FSS are planar frequency sensitive structures typically consisting of repeating pattern of a simple motif like square, circle, etc. LÄS MER

  3. 3. Design of Functional Structures and Measurement Techniques for Electromagnetic Waves

    Författare :Johan Lundgren; Teoretisk elektroteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; functional structures; frequency selective structures; polarization selectivity; metasurface; near-field measurements; antenna measurements; scattering measurement; power density; random media;

    Sammanfattning : Electromagnetic fields exist all around us. Through evolution, nature has developed tools to interact and use these fields, where our eyes are a spectacular example. Humans have a long history of developing structures and objects of their own to alter and interact with these fields. LÄS MER

  4. 4. Analysis of Conformal Antennas and Periodic Structures

    Författare :Silvia Raffaelli; Chalmers University of Technology; []
    Nyckelord :method of moments; microstrip; corrugated surface; horn; Floquet; array; periodic; multilayer structure; finite difference time domain; dual-frequency; infinite; spectral domain analysis; conformal antenna;

    Sammanfattning : In the last decades much attention has been paid to the design of high-performance antennas. Accurate control of the radiation properties is very important in electromagnetic engineering applications. LÄS MER

  5. 5. Scattering and propagation of electromagnetic waves in planar and curved periodic structures - applications to plane wave filters, plane wave absorbers and impedance surfaces

    Författare :Ola Forslund; KTH; []
    Nyckelord :electromagnetic scattering; periodic structure; frequency selectiove structure; frequency selective surface;

    Sammanfattning : The subject of this thesis is scattering of electromagneticwaves from planar and curved periodic structures. The problemspresented are solved in the frequency domain.Scattering from planar structures with two-dimensionalperiodic dependence of constitutive parameters is treated. LÄS MER