NL
Authored
14 records found
DESHIMA 2.0
Development of an Integrated Superconducting Spectrometer for Science-Grade Astronomical Observations
Integrated superconducting spectrometer (ISS) technology will enable ultra-wideband, integral-field spectroscopy for (sub)millimeter-wave astronomy, in particular, for uncovering the dust-obscured cosmic star formation and galaxy evolution over cosmic time. Here, we present the d
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Time-Domain Modelling of Pulsed Photoconducting Sources - Part I
The Norton Equivalent Circuit
In the circuit theory, the Norton and Thevenin equivalent generators are tools that simplify the solutions of networks involving passive or active components. They have been extensively used in the frequency domain to describe time-harmonic sources. A time-stepped evolution is in
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On the Near-Field Spherical Wave Formation in Resonant Leaky-Wave Antennas
Application to Small Lens Design
In this work, we show that the near field of leaky-wave resonant antennas (LWAs) radiating into a dense medium can be locally represented as a spherical wave in a certain solid angle around broadside using an accurate definition of the phase center. The near field in this solid a
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Time-Domain Modelling of Pulsed Photoconducting Sources - Part II
Characterization of an LT GaAs Bow-Tie Antenna
Drude's description of the response of low-temperature gallium arsenide to optical pulse excitation is used to evaluate the components of a time-domain Norton equivalent circuit of a photoconductive antenna (PCA) source. The saturation of the terahertz (THz) radiated power occurr
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Norton Equivalent Circuit for Pulsed Photoconductive Antennas-Part I
Theoretical Model
A novel equivalent circuit for pulsed photoconductive sources is introduced for describing the coupling between the photoconductive gap and the antenna. The proposed circuit effectively describes the mechanism of feeding the antenna by the semiconductor when this latter is illumi
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Dual Band Kinetic Inductance Bolometers for Submillimeter-wave Imaging
Experimental and Theoretical Optical Response
In this contribution, a focal plane array (FPA) at submillimeter wavelengths is presented for security applications. The detectors are based on kinetic inductance bolometers. Two frequency selective absorber (FSA) sets were designed to implement a security imager. The effective p
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Norton Equivalent Circuit for Pulsed Photoconductive Antennas - Part II
Experimental Validation
This second part of two papers' sequence presents the experimental validation of the Norton equivalent circuit model for pulsed photoconductive antennas (PCAs) provided in the first paper of the sequence. To this goal, different prototypes of photoconductive antenna sources have
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Incoherent Detection of Orthogonal Polarizations via an Antenna Coupled MKID
Experimental Validation at 1.55 THz
There is an increasing demand for large format detector arrays with large bandwidths and high antenna efficiencies for future THz astronomical radiometric applications. For direct detection instruments, it is also desired to have antennas with dual polarization reception in order
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Reception Power Pattern of Distributed Absorbers in Focal Plane Arrays
A Fourier Optics Analysis
Passive imaging cameras at millimeter and submillimeter wavelengths are currently entering a new era with the development of large format arrays of direct detectors. Several of these arrays are being developed with bare absorbing meshes without any antenna coupling (lens or horn)
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SPACEKIDS
Kinetic inductance detectors for space applications
SPACEKIDS, a European Union FP-7 project, has recently been completed. It has focused on developing kinetic inductance detector (KID) arrays and demonstrating their suitability for space applications at far infrared and submillimetre wavelengths. KID arrays have been developed fo
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SPACEKIDS
Kinetic inductance detectors for space applications
SPACEKIDS, a European Union FP-7 project, has recently been completed. It has focused on developing kinetic inductance detector (KID) arrays and demonstrating their suitability for space applications at far infrared and submillimetre wavelengths. KID arrays have been developed fo
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Time-domain EM numerical modelling
A pulse shape causality and temporal support analysis
A number of model-pulses to be used for feeding purposes in time-domain, electromagnetic simulations are compared. The pulses' causality and temporal support are employed as discriminating features. CST Microwave Studio® simulations of a canonical configuration are employed for a
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MIMO Antennas for Radiative Near-Field Links
A Comparative Study at 300 GHz
This paper presents a comparative study of different Multiple Input Multiple Output (MIMO) array architectures to realize high-capacity Point-to-Point (PtP) wireless links for potential use in future 6G backhauling applications. This study focuses on the 220-320 GHz band, defined
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Photoconductive connected array
A novel solution for pulsed terahertz radiation
A novel design of an optically pumped THz photoconductive source in array configuration is presented. The proposed solution is based on the exploitation of the ultrawide band properties of connected antenna arrays. The photoconductive elements of the array are excited by an array
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Contributed
6 records found
Non-intrusive patient monitoring to prevent pressure ulcers
Algorithm Subgroup
The founders of Momo Medical envisioned a health care product that would help nurses worldwide with pressure ulcer prevention. Pressure ulcers are a chronic wound that affects the skin of patients who do not regularly change bed posture. As it currently stands, nurses lack the ma
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Image-Based Video Search Engine
Feature Extraction
One of the main problems with Instance-Level Image Retrieval in video data is that for query videos with multiple objects of the same instance, extracting features from keyframes of this query video is time consuming. This thesis aims to solve this problem by implementing a Convo
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Distributed Excitations of Pulsed Photo-Conductive Sources
The Time Domain Analysis
Distributed feeding in photo-conducting antennas (PCAs) leads to simple optical designs, less prone to overheating, as well to terahertz (THz) antennas that can operate non-dispersively over wide bandwidths. However, the efficient analysis of pulsed PCAs was so far limited to arc
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Non-intrusive patient monitoring for pressure ulcer prevention
Group F - Test Group
Problem Definition
This bachelor final project was an assignment given by the start up Momo Medical named: "Improving health care with technology". This project was to use their existing technology and ideas to create a system to prevent pressure ulcers. Pressure ulcer are the me
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Scanning Lens Phased Array Antennas
Analysis, design and demonstrations at millimeter and submillimeter wavelengths using leaky-wave feeds
Millimeter- and submillimeter wave applications, such as point-to-point wireless communications in beyond-5G scenarios, long-range automotive radars and astronomy and astrophysics science cases from space require antennas with high-gain beams that are steerable. At lower (microwa
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Self-Supervised Federated Learning at the Edge
Hardware & System Development
This thesis serves to finalise the bachelor graduation project on the topic of self-supervised federated learning, specifically the on-chip implementation of the algorithms. The goal of the project is to implement a self-supervised learning setup in a decentralised approach using
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