Sökning: "periodic structure"

Visar resultat 1 - 5 av 141 avhandlingar innehållade orden periodic structure.

  1. 1. Analysis of Conformal Antennas and Periodic Structures

    Författare :Silvia Raffaelli; [2001]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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

  2. 2. Nonlinear Approaches to Periodic Signal Modeling

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Emad Abd-Elrady; Torsten Söderström; Torbjörn Wigren; Jonas Sjöberg; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cramer-Rao bounds; frequency estimation; identification; limit cycle; nonlinear systems; periodic signals; Wiener model structure; TECHNOLOGY Information technology Signal processing; TEKNIKVETENSKAP Informationsteknik Signalbehandling; Signal Processing; Signalbehandling;

    Sammanfattning : Periodic signal modeling plays an important role in different fields. The unifying theme of this thesis is using nonlinear techniques to model periodic signals. The suggested techniques utilize the user pre-knowledge about the signal waveform. This gives these techniques an advantage as compared to others that do not consider such priors. LÄS MER

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

    Detta är en avhandling från Stockholm : Alfvénlaboratoriet

    Författare :Ola Forslund; [2004]
    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

  4. 4. Acoustic excitation and transmission of lightweight structures

    Detta är en avhandling från Div. Engineering Acoustics, LTH

    Författare :Jonas Brunskog; [2002]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; point mobility; Lamb waves; wood.; Building construction; plate excitation; cavities; near-periodicity; nearly periodic; sound insulation; timber; structural acoustics; spatial Fourier transform; resilient device; prediction model; periodic; lightweight; ISO tapping machine; airborne noise; Building acoustics; impact noise; Byggnadsteknik;

    Sammanfattning : In order to increase our knowledge of the sound transmission and radiation processes of lightweight wall and floor structures, theoretical models are needed. Detailed models may form a valuable tool. In lightweight floor structures, impact sound insulation is perhaps the most important property to consider. LÄS MER

  5. 5. On the analysis of soft surfaces, frequency selective surfaces and con­formal antennas

    Detta är en avhandling från Div. Engineering Acoustics, LTH

    Författare :Silvia Raffaelli; [1999]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; array; microstrip; antenna; dual-frequency; corrugated surface; multi-layer structure; periodic; horn; finite difference time domain; method of moments; spectral domain analysis; infinite;

    Sammanfattning : .... LÄS MER