On the Excitation of Anomalous EM Transients Along the Surface of a Thin Highly Contrasting Sheet With Dielectric and Conductive Properties

The electric-line-source excited, pulsed electromagnetic (EM) field response on the surface of a highly contrasting thin sheet with dielectric and conductive properties is studied analytically in the time domain (TD) with the aid of the Cagniard-De Hoop technique. Closed-form TD expressions reveal anomalous highly oscillatory EM transients...

Experimental investigation of wave tip variability of impacting waves

We present an experimental study on the variation in wave impact location and present a mechanism for the development of free surface instabilities on the wave crest for repeatable plunging wave impacts on a vertical wall. The existence of free surface instabilities on an impacting wave is well known, but their characteristics and formation...

Early design of the MOSAIC antenna

The work of this thesis has been carried out in the framework of the project Multi-Object Spectrometer with an Array of superconducting Integrated Circuits, also known as MOSAIC. The aim of this instrument is to resolve the Cosmic Infrared Background (CIB) from a 10 m diameter ground-based telescope. MOSAIC will be the first multi-object three...

Surface Wave Analysis for the characterization of granular material deposits

Knowledge of near-surface seismic-wave velocity of granular materials plays a valuable role in seismic exploration data processing. I will use the surface-wave analysis method for estimation of shear-wave velocity profile and P-wave refraction for estimation of pressure-wave velocity on a data set acquired over a sand dune in The Netherlands, a...

Characterization of Printed Transmission Lines at High Frequencies

In this contribution, a quasi-analytical model is proposed allowing for fast characterization of a wide variety of printed transmission lines in terms of characteristic impedance, effective dielectric constant and losses. These losses are composed out of conductor losses, dielectric losses and radiation losses due to space and surface wave...

Impact of a half-space interface on the wireless link between tiny sensor nodes

The power budget of a wireless link between two electrically small sensor nodes located close to an interface between two media is studied. The model includes both the propagation channel losses and input impedance of the radio frequency antennas. It is shown that a highly inductive half-space significantly enhances the received power due to the...

Dispersion of Electromagnetic Waves in a Periodic Open Waveguide

We model guided modes for an infinitely long metallic structure in the lateral direction that is invariant in the transverse direction, and mechanically supported by a dielectric layer This modeling is done without making any assumptions about the width of the slots relative to the spatial period. We do this by representing the electric field by...

Whitecapping and wave field evolution in a coastal bay

Evolution of the wave field in a coastal bay is investigated, by comparison between field observations and numerical simulations using a spectral wave model (Simulating WAves Nearshore (SWAN)). The simulations were conducted for the passage of an extratropical storm, during which surface elevation spectra were bimodal owing to local wind-sea...

Nonlinear surface waves over topography

As ocean surface waves radiate into shallow coastal areas and onto beaches, their lengths shorten, wave heights increase, and the wave shape transforms from nearsinusoidal to the characteristic saw-tooth shapes at the onset of breaking; in the ensuing breaking process the wave energy is cascaded to small-scale turbulent motions in the surf zone....

Shape resonance omni-directional terahertz filters with near-unity transmittance

Terahertz transmission filters have been manufactured by perforating metal films with various geometric shapes using femtosecond laser machining. Two dimensional arrays of square, circular, rectangular, cshaped, and epsilon-shaped holes all support over 99% transmission at specific frequencies determined by geometric shape, symmetry,...