Searched for: subject%3A%22antennas%22
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Tan, Junyao (author)
This master thesis explores the capacity of MIMO arrays for communication in the radiative near field through antenna design. This research applies an in-house MATLAB model based on free space Green’s function to calculate the channel matrix, revealing the potential increase of capacity through the use of incoherent arrays with directive...
master thesis 2023
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Beijnen, Laurens (author)
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 architectures characterized by feeds small with respect to the THz...
master thesis 2023
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Zhang, Muhan (author)
Recently, there has been an increasing demand for security in public places. As a result, non-destructive and fast millimetre-wave and submillimetre-wave imaging systems have gained more and more attention.<br/>This project is based on Concealed Objects Stand-off Real-Time Imaging for Security (CONSORTIS), which is a European next-generation...
master thesis 2023
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Kooij, Roeland (author)
As the world is getting used to 5G technology, 6G is already on the horizon. With the ultimate goal of very low latency communication and Tbps data rates, 6G supports new wireless technologies such as virtual and augmented reality and autonomous driving. In this new generation of wireless communication, high frequencies up to 100 GHz are used...
master thesis 2023
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Hu, Weiya (author)
Flat lens antennas are convenient solutions to realize highly directive antennas for millimeter wave and terahertz frequencies. Unlike the traditional three-dimensional bulky lens antennas, flat lenses are compact, low profile, and planar structures that can be manufactured with standard multi-layer technology, e.g. printed circuit board (PCB)...
master thesis 2023
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Subramani, Surya Natarajan (author)
Radiation pattern measurements is a critical step in characterizing antennas before they are used in any system for a specific application. To identify any defects or to acquire the true radiation characteristics of the antenna under test, densely sampled measurements are desired. However, this results in a time and cost expensive measurement...
master thesis 2023
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Griffith, Kiana (author)
This thesis analyzes and describes a wearable pressure sensor to detect intraocular pressure and guide clinician diagnosis of glaucoma. Although glaucoma has many<br/>symptoms and risk factors, high intraocular pressure is the most predominant. A method to continuously and accurately record intraocular pressure measurements and fluctuations in a...
master thesis 2023
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Anand Nair, Keshav (author)
The mm-wave operational band (24-30 GHz) is becoming increasingly important for various practical applications. However, at such high frequencies, the issue of propagation losses arises, emphasizing the necessity for these systems to achieve high radiation efficiency. Dielectric Resonator Antennas (DRA) are promising candidates to replace...
master thesis 2023
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Bechrakis Triantafyllos, Alexandros (author)
In the framework of this MSc thesis the analysis of core-shell leaky-wave lens antennas is presented, based on a combination of asymptotic and Physical Optics techniques. This study aims to develop an analysis approach which can be subsequently used for the optimization of the Fly’s Eye antenna concept, through enabling the investigation of...
master thesis 2023
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Mavropoulou, Alexandra (author)
In the framework of this MSc thesis, the analysis and design guidelines for part of the quasi-optical system of a proposed astronomical instrument, called TIFUUN, are presented. The TIFUUN instrument is an imaging spectrometer, planned to be placed in the ASTE telescope to perform ground-based astronomical observations in the mm-submm wavelength...
master thesis 2023
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Zhao, Changxu (author)
With the development of the fifth generation (5G) technologies and beyond, the requirements for future wireless communication systems become more stringent, which demand novel antenna design at millimetre waves. The most commonly proposed array topology for 5G usage is square 8x8 or 16x16 microstrip patches with the full digital beam-forming...
master thesis 2023
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Tapia Barroso, Roderick (author)
Future communication scenarios will require massive Multiple-input multiple-output (MIMO) by the use of multi-beam antenna systems. Maximizing the number of beams for a given antenna size is paramount given that the space allocated to the antenna is often limited. This work aims at evaluating the maximum number of beams by analyzing the SIR in...
master thesis 2023
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Bosma, S. (author)
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 (microwave) frequencies, fully sampled phased arrays with thousands of...
doctoral thesis 2023
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Mier Escurra, C. (author), Mor, A. R. (author), Vaessen, P.T.M. (author), Lathouwers, A.G.A. (author)
One of the main difficulties in measuring partial discharges (PD) in gas-insulated substations (GIS) is the overlapping of pulses at the sensor's location, which distorts the pulse resolution and the charge estimation. This research presents a new method called “synergy,” which identifies and suppresses reflections using magnetic and electric...
journal article 2023
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Hehenberger, S.P. (author), Caizzone, Stefano (author), Yarovoy, Alexander (author)
The utilization of additive manufacturing (AM) to engineer the permittivity profile of dielectric resonator antennas (DRAs) is considered. For the first time, the capabilities of AM are exploited to create continuously swept permittivity profiles and applied to cylindrical DRAs. The spatial variant lattices (SVL) synthesis algorithm is...
journal article 2023
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Patel, Kartik (author), Myers, N.J. (author), Heath, Robert W. (author)
Millimeter wave (mmWave) technology can achieve high-speed communication due to the large available spectrum. Furthermore, the use of directional beams in mmWave system provides a natural defense against physical layer security attacks. In practice, however, the beams are imperfect due to mmWave hardware limitations such as the low-resolution...
journal article 2023
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Gaspar Silva, Jose Rui (author), Finkel, M. (author), Laauwen, Wouter M. (author), Yates, S.J.C. (author), Mirzaei, B. (author), Vercruyssen, N. (author), Young, Abram (author), Walker, Christopher (author), Gao, J.R. (author)
We have simulated and measured the beam properties of lens-antenna coupled hot electron bolometer mixers at a few supra-terahertz frequencies between 1.4 and 5.3 THz. The quasi-optical structures consist of an elliptical lens and a logarithmic spiral antenna. The model used for our simulations consists of a finite-element analysis to simulate...
journal article 2023
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Çelik, F.T. (author), Joof, Sulayman (author), Karacuha, Kamil (author)
The present study proposes a dual-polarized bandwidth-enhanced filtering specialized dipole antenna design for 5G by employing a wide printed dipole, filtering resonators, a reflector surface, and specially designed balun structures. Such a configuration is commonly deployed in conventional base stations. To increase the antenna impedance and...
journal article 2023
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Bueno Lopez, J. (author), Sberna, P.M. (author), Fiorellini Bernardis, A. (author), Zhang, H. (author), Neto, A. (author), Llombart, Nuria (author)
State-of-the-art THz pulsed commercial systems operating over large bandwidth suffer from high dispersion or low radiation efficiency due to the poor coupling between the transmitter and receiver photoconductive antennas (PCAs). In this work, we present the fabrication and characterization of a leaky-lens PCA that has the potential to solve...
journal article 2023
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Fiorellini Bernardis, A. (author), Sberna, P.M. (author), Bueno Lopez, J. (author), Zhang, H. (author), Llombart, Nuria (author), Neto, A. (author)
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 occurring at large optical excitation levels was previously associated...
journal article 2023
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