Sökning: "aperture coupled"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden aperture coupled.

  1. 1. Grouting of Hard Rock with Gelling Liquids, Field and Laboratory Studies of Silica sol

    Författare :Johan Funehag; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; aperture; penetration length; gelling liquids; field study; silica sol; colloidal silica; Grouting; propagation; hydraulic test; sand column; rheology; transmissivity;

    Sammanfattning : Recent grouting projects in Sweden have concentrated on the grout itself. The only grout normally used in Sweden is a cement-based one. During the past 10 years, the acceptable flow of water into tunnels has been significantly reduced. The current requirements mean that an average fracture aperture of around 0. LÄS MER

  3. 2. Analysis of Dipole and Patch Antennas in Cylindrical Structures

    Författare :Peter Slättman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fourier transform; cross-section; patch; slot; arbitrary; EFIE; trough guide; cylindrical; dipole; moment method; antenna; aperture coupled;

    Sammanfattning : This thesis deals with the analysis of dipoles, patches, and aperture coupled patches located in an infinitely long cylindrical structure with arbitrary cross-section. The analysis exploits the two-dimensional nature of the structure by expanding all fields and currents in spatial harmonics along the cylinder axis, and solving the subsequent spectral two-dimensional problems by the moment method. LÄS MER

  4. 3. Analysis and Design of Base Station Antennas for Mobile Communications

    Författare :Björn Lindmark; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; polarization diversity; dual polarization; adaptive antennas; moment method; genetic algorithm; antenna arrays; radio propagation; channel sounding; aperture coupled patch;

    Sammanfattning : The thesis deals with base station antennas and the environment they work in. Polarization diversity, dual band operation, and adaptive antenna systems are discussed with emphasis on how antennas for these applications should be designed. We compare the polarization diversity performance of different types of dual polarized antenna elements. LÄS MER

  5. 4. Polarization diversity and array signal processing in base station antennas

    Författare :Björn Lindmark; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; signal correlation; mobile communication; rayleigh fading; wireless communication; multibeam; dual band; dual polarized; multual coupling; infinite arrays; aperture coupled patch; antenna arrays;

    Sammanfattning : .... LÄS MER

  7. 5. The Impact of Fracture Geometry on the Hydromechanical Behaviour of Crystalline Rock

    Författare :Johan Thörn; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Laboratory experiments; Fracture aperture; In situ experiments; Conceptual model; Äspö HRL; Fracture geometry; Stereo photogrammetry; Hydromechanical coupling; Fracture normal stiffness;

    Sammanfattning : Effective construction of tunnels in fractured crystalline rock requires a unified approach for handling rock mechanics and hydrogeological issues. Traditionally, rock mechanics and hydrogeology not only use different nomenclature, they also measure parameters such as e.g. aperture differently. LÄS MER