Mv
M. van Zonneveld
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1
Gradient-index (GRIN) flat lenses are a promising solution for millimeter-wave antenna systems, offering high gain, wide-angle beam steering, and a low-profile form factor that is well suited for integration with modern wireless platforms. However, the analysis and optimization of electrically large GRIN lenses using full-wave electromagnetic solvers are computationally expensive, making rapid design iterations impractical.
This thesis presents an efficient semi-analytical framework for the analysis of GRIN flat lens antennas that combines geometrical optics ray tracing, the ray tube theorem, transmission-line modeling, and physical optics to predict aperture fields and far-field radiation characteristics. The framework is extended with generalized matching-layer synthesis, automatic lens-thickness compensation, polarization tracking, multilayer propagation modeling, and support for off-axis feed excitation, enabling the efficient evaluation of beam steering and scanning performance. The complete analysis procedure is implemented in a MATLAB-based graphical user interface to facilitate practical lens design and performance assessment.
The proposed method is extensively validated against full-wave CST simulations for both center-fed and off-axis-fed configurations. Excellent agreement is obtained, with predicted peak directivity typically within 0.1 dB for broadside operation and within 0.2–0.5 dB for large beam-scanning cases. The study also investigates the influence of anisotropy in artificial dielectric layers, demonstrating that scalar refractive-index models are insufficient to accurately describe anisotropic behavior. In addition, a novel output-angle-based refractive-index compensation method is introduced, which effectively corrects profile errors and can be employed as an iterative GRIN lens synthesis technique.
The developed framework provides an accurate and computationally efficient alternative to full-wave analysis, reducing complete lens evaluation times from several hours to typically less than two minutes after feed characterization. This enables rapid design optimization while maintaining practical accuracy, making the tool well suited for the development of electrically large GRIN flat lens antennas for millimeter-wave applications. ...
This thesis presents an efficient semi-analytical framework for the analysis of GRIN flat lens antennas that combines geometrical optics ray tracing, the ray tube theorem, transmission-line modeling, and physical optics to predict aperture fields and far-field radiation characteristics. The framework is extended with generalized matching-layer synthesis, automatic lens-thickness compensation, polarization tracking, multilayer propagation modeling, and support for off-axis feed excitation, enabling the efficient evaluation of beam steering and scanning performance. The complete analysis procedure is implemented in a MATLAB-based graphical user interface to facilitate practical lens design and performance assessment.
The proposed method is extensively validated against full-wave CST simulations for both center-fed and off-axis-fed configurations. Excellent agreement is obtained, with predicted peak directivity typically within 0.1 dB for broadside operation and within 0.2–0.5 dB for large beam-scanning cases. The study also investigates the influence of anisotropy in artificial dielectric layers, demonstrating that scalar refractive-index models are insufficient to accurately describe anisotropic behavior. In addition, a novel output-angle-based refractive-index compensation method is introduced, which effectively corrects profile errors and can be employed as an iterative GRIN lens synthesis technique.
The developed framework provides an accurate and computationally efficient alternative to full-wave analysis, reducing complete lens evaluation times from several hours to typically less than two minutes after feed characterization. This enables rapid design optimization while maintaining practical accuracy, making the tool well suited for the development of electrically large GRIN flat lens antennas for millimeter-wave applications. ...
Gradient-index (GRIN) flat lenses are a promising solution for millimeter-wave antenna systems, offering high gain, wide-angle beam steering, and a low-profile form factor that is well suited for integration with modern wireless platforms. However, the analysis and optimization of electrically large GRIN lenses using full-wave electromagnetic solvers are computationally expensive, making rapid design iterations impractical.
This thesis presents an efficient semi-analytical framework for the analysis of GRIN flat lens antennas that combines geometrical optics ray tracing, the ray tube theorem, transmission-line modeling, and physical optics to predict aperture fields and far-field radiation characteristics. The framework is extended with generalized matching-layer synthesis, automatic lens-thickness compensation, polarization tracking, multilayer propagation modeling, and support for off-axis feed excitation, enabling the efficient evaluation of beam steering and scanning performance. The complete analysis procedure is implemented in a MATLAB-based graphical user interface to facilitate practical lens design and performance assessment.
The proposed method is extensively validated against full-wave CST simulations for both center-fed and off-axis-fed configurations. Excellent agreement is obtained, with predicted peak directivity typically within 0.1 dB for broadside operation and within 0.2–0.5 dB for large beam-scanning cases. The study also investigates the influence of anisotropy in artificial dielectric layers, demonstrating that scalar refractive-index models are insufficient to accurately describe anisotropic behavior. In addition, a novel output-angle-based refractive-index compensation method is introduced, which effectively corrects profile errors and can be employed as an iterative GRIN lens synthesis technique.
The developed framework provides an accurate and computationally efficient alternative to full-wave analysis, reducing complete lens evaluation times from several hours to typically less than two minutes after feed characterization. This enables rapid design optimization while maintaining practical accuracy, making the tool well suited for the development of electrically large GRIN flat lens antennas for millimeter-wave applications.
This thesis presents an efficient semi-analytical framework for the analysis of GRIN flat lens antennas that combines geometrical optics ray tracing, the ray tube theorem, transmission-line modeling, and physical optics to predict aperture fields and far-field radiation characteristics. The framework is extended with generalized matching-layer synthesis, automatic lens-thickness compensation, polarization tracking, multilayer propagation modeling, and support for off-axis feed excitation, enabling the efficient evaluation of beam steering and scanning performance. The complete analysis procedure is implemented in a MATLAB-based graphical user interface to facilitate practical lens design and performance assessment.
The proposed method is extensively validated against full-wave CST simulations for both center-fed and off-axis-fed configurations. Excellent agreement is obtained, with predicted peak directivity typically within 0.1 dB for broadside operation and within 0.2–0.5 dB for large beam-scanning cases. The study also investigates the influence of anisotropy in artificial dielectric layers, demonstrating that scalar refractive-index models are insufficient to accurately describe anisotropic behavior. In addition, a novel output-angle-based refractive-index compensation method is introduced, which effectively corrects profile errors and can be employed as an iterative GRIN lens synthesis technique.
The developed framework provides an accurate and computationally efficient alternative to full-wave analysis, reducing complete lens evaluation times from several hours to typically less than two minutes after feed characterization. This enables rapid design optimization while maintaining practical accuracy, making the tool well suited for the development of electrically large GRIN flat lens antennas for millimeter-wave applications.
Simulation of the Dutch electricity system
A software expansion for the Illuminator
The aim of this report is to discuss the design of the software that creates a simulation for the national electricity grid level of the Netherlands. This is done by further developing the open-source energy system integration development kit called the Illuminator. Where the goal of this software is to create an extra case, add a Graphical User Interface (GUI), and add a way to evaluate created configurations.
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The aim of this report is to discuss the design of the software that creates a simulation for the national electricity grid level of the Netherlands. This is done by further developing the open-source energy system integration development kit called the Illuminator. Where the goal of this software is to create an extra case, add a Graphical User Interface (GUI), and add a way to evaluate created configurations.