Searched for: subject%3A%22lens%255C%2Bantennas%22
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Zhang, H. (author)
In recent decades, dielectric lens antennas have been more and more adopted and developed for sensing and imaging applications at sub-millimeter (sub-mm) wavelengths because they can achieve high gain while keeping their physical size and weight acceptable at these wavelengths. More recently, as low-loss and low-cost lens materials have become...
doctoral thesis 2024
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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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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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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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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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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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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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Hoogelander, M. (author), van Berkel, S.L. (author), Malotaux, E.S. (author), Alonso Del Pino, M. (author), Cavallo, D. (author), Spirito, M. (author), Llombart, Nuria (author)
This article presents the development of a focal plane array (FPA) for terahertz imaging applications with a near diffraction-limited resolution achieved through a very tight sampling of the focal plane. The antenna array is integrated with direct detectors in a 22-nm CMOS technology and operates from 200 to 600 GHz. The tight sampling of the...
journal article 2023
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Gottmer, Leila (author)
In this thesis, an efficient optimization method is described for synthesizing lens antennas fabricated in low permittivity plastic materials to achieve wide scanning performances. The method is based on an antenna in reception representation. The optimized parameters are the location and orientation of the antenna feeder, lens angular region...
master thesis 2022
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Fiorellini Bernardis, A. (author)
In recent years, the interest in terahertz technology witnessed a constant increasing interest and attention from the scientific community, as it allows to unlock the THz bandwidth, that can be used for a wide range of applications: it helps the study of biological samples and help medical diagnostics; it serves as a harmless non-destructive...
doctoral thesis 2022
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Bosma, S. (author), Neto, A. (author), Llombart, Nuria (author)
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 angle can be efficiently evaluated through the integration of the...
journal article 2022
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Bosma, S. (author), van Rooijen, N. (author), Alonso Del Pino, M. (author), Llombart, Nuria (author)
We present a resonant leaky-wave lens antenna, fed by a circular waveguide with annular corrugations in the ground plane. The proposed leaky-wave feed reduces the impact of the spurious TM0 leaky-wave mode in all planes over a wide bandwidth while reducing assembly complexity compared to previous methods. The proposed leaky-wave antenna has...
journal article 2022
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Bosma, S. (author), van Rooijen, N. (author), Alonso Del Pino, M. (author), Spirito, M. (author), Llombart, Nuria (author)
We report on the first demonstration of dynamic beam steering using a scanning lens phased array. A scanning lens phased array relies on a combination of mechanical and electrical phase shifting to dynamically steer a high-gain beam beyond the grating-lobe free region using a sparse array. These two concepts have been demonstrated separately in...
journal article 2022
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Bueno Lopez, J. (author), Bosma, S. (author), Bußkamp-Alda, Tobias (author), Alonso Del Pino, M. (author), Llombart, Nuria (author)
We present the design, fabrication and characterization of a broadband lossless matching layer for silicon lens arrays. The proposed matching layer is based on silicon frusta (truncated pyramids) on top of the lens array fabricated by means of laser ablation. This matching layer is advantageous over quarter-wavelength dielectric matching...
journal article 2022
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Nair, Ashwita (author)
Lens array architectures are being developed for high frequency applications such as phased arrays for 5G point-to-point communications, Fly’s Eye lens arrays for wideband wireless communications and scanning phased arrays at sub-millimeter wavelengths. Each of these applications employ different feed configurations, lens geometries and require...
master thesis 2021
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Arias Campo, M. (author)
The expanding demand for high-speed wireless communications is pushing current networks and systems close to their limits. The use of sub-THz bands, where large bandwidth is available, is pointed out as one of the key strategies to cope with the huge amount of data transfer in the next Beyond 5G and 6G communications generations. Despite the...
doctoral thesis 2021
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Zhang, H. (author), Bosma, S. (author), Neto, A. (author), Llombart, Nuria (author)
A dual-polarized 4 x 4 scanning phased array antenna with leaky-wave enhanced lenses operating at 28 GHz is presented. Such an antenna can be used for point-to-point fifth-generation (5G) communications that require high gain, wide bandwidth (BW), and limited steering ranges. The proposed array has a periodicity of two wavelengths, and the...
journal article 2021
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Arias Campo, M. (author), Carluccio, G. (author), Bruni, Simona (author), Llombart, Nuria (author)
Low relative permittivity plastic elliptical lenses in combination with integrated focal plane arrays are a promising solution to be used in the future mm- and sub-mm-wave systems. Their appeal lies in the availability of materials with moderate loss and lightweight, and the possibility to use cost-effective manufacturing techniques. However,...
journal article 2021
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Arias Campo, M. (author), Carluccio, G. (author), Blanco, Darwin (author), Litschke, Oliver (author), Bruni, Simona (author), Llombart, Nuria (author)
In this contribution, a broadband G-band leaky-wave (LW) fed lens antenna with an integrated dielectric grid polarizer is presented. The proposed wideband polarizer unit cell geometry enables its fabrication at frequencies higher than 100 GHz, presenting high transmission properties and low axial ratio (AR). A quasi-Analytic technique based...
journal article 2021
Searched for: subject%3A%22lens%255C%2Bantennas%22
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