Searched for: author%3A%22Cavallo%2C+D.%22
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Ozzola, R. (author), Neto, A. (author), Imberg, Ulrik (author), Cavallo, D. (author)
We present a dual-polarized connected array of slots with an artificial dielectric layer (ADL) radome for mobile communication applications operating in the sub-6 GHz and the upper 6 GHz bands of 5G. The radiating slots are combined with two interchangeable ADL radomes with different thicknesses, targeting the bands 6-8 and 2-8 GHz,...
journal article 2024
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Coco Martin, C.M. (author), Hu, Weiya (author), Cavallo, D. (author)
This work aims to provide guidelines on the design of wideband flat lenses based on artificial dielectric layers (ADLs). Planar lenses based on metasurfaces are typically narrowband, due to the phase wrapping over the period of 2\pi that is strongly frequency-dependent. On the contrary, true-time-delay (TTD) planar lenses, which do not resort...
journal article 2024
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Hu, Weiya (author), Coco Martin, C.M. (author), Cavallo, D. (author)
A semi-analytical method is presented for the design of gradient index (GRIN) flat lenses. Closed-form expressions are derived to define the refractive index distribution of the lens, for several cases: collimating lenses with on-axis feed, collimating lenses with off-axis feed, lenses converting spherical wavefronts with different...
journal article 2024
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van Schelven, R.M. (author), Syed, Waqas (author), Carluccio, G. (author), Doris, Kostas (author), de Graauw, Anton (author), Neto, A. (author), Cavallo, D. (author)
In this work, we investigate antenna architectures to implement dual-mode operation in phased array designs. Planar slot antenna elements are used in array configuration, in combination with artificial dielectrics layers (ADLs) located in the close proximity of the array, to achieve pattern shaping. The artificial dielectric superstrate...
journal article 2023
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van Schelven, R.M. (author), Spirito, M. (author), Cavallo, D. (author)
In this study, an efficient power combiner for mm-wave frequency transmitters is investigated. The combiner is based on a parallel plate waveguide (PPW) excited with multiple parallel feeds. The Doherty power combiner scheme is also integrated in the proposed concept, to increase the efficiency of the amplifiers when implementing amplitude...
journal article 2023
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Cavallo, D. (author)
Artificial Dielectric Layers (ADLs) have recently been exploited to improve the radiation and impedance performance of integrated antennas at millimeter wave (mmWave) and terahertz (THz) frequencies. The ADLs are composed by layers of sub-wavelength periodic metal patches that can be arranged within a host medium to synthesize an equivalent...
conference paper 2023
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Amendola, Giandomenico (author), Cavallo, D. (author), Chaloun, Tobias (author), Defrance, Nicolas (author), Goussetis, George (author), Margalef-Rovira, Marc (author), Martini, Enrica (author), Quevedo-Teruel, Oscar (author), Valenta, Vaclav (author)
Low-Earth orbit (LEO) constellations are revolutionizing the world of satellite communication (Satcom), providing new opportunities to manufacturers and operators and enabling innovative and attractive services to users.
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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van Schelven, R.M. (author), Cavallo, D. (author)
We present a general analysis to describe nonsquare artificial dielectric layers (ADLs). Closed-form expressions for the equivalent layer impedance are given for generic plane-wave incidence, assuming that the ADLs have different geometrical parameters in the {x}-and {y}-directions. The analytical expressions account for the interaction...
journal article 2022
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Pascual Laguna, A. (author), Cavallo, D. (author), Baselmans, J.J.A. (author), Llombart, Nuria (author)
This communication proposes a broadband and efficient integrated focal plane array solution based on a near-field focused connected array of slots. The focused aperture provides: 1) broadband and highly efficient illumination of the quasi-optical system and 2) scanning capabilities within a focusing system. The connected array antenna in turn...
journal article 2022
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Cavallo, D. (author)
A novel approach for the practical realization of the feeding lines in connected array of slots is presented. The proposed feed concept is based on a parallel-plate waveguide (PPW) structure and allows simplifying the unit cell design. When compared to the typical integrated coaxial feed, the PPW-based feeding structure can reduce the cost...
journal article 2022
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Ozzola, R. (author), Cavallo, D. (author), Neto, A. (author)
We present a study on beam coupling in radiating structures that support multiple simultaneous beams. The formation of multiple beams is relevant in modern wireless communication applications when diverse data streams can be sent from a single transmitter to users located in different directions. General expressions are provided that relate...
journal article 2022
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Van Katwijk, Alexander J. (author), Neto, A. (author), Toso, Giovanni (author), Cavallo, D. (author)
We present an efficient method for the analysis of finite connected slot arrays in the presence of stratified media. The formulation is based on a spectral method of moments, where only one basis function is considered for each array element and one for each slot edge. An expression for the mutual impedance is derived in terms of a double...
journal article 2022
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Hoogelander, M. (author), van Berkel, S.L. (author), Malotaux, E.S. (author), Alonso Del Pino, M. (author), Spirito, M. (author), Neto, A. (author), Cavallo, D. (author), Llombart, Nuria (author)
In this contribution we will present the diffraction-limited imaging capabilities of a focal plane array (FPA) of antenna-coupled direct-detectors at submillimeter wavelengths. The FPA prototype is a tightly sampled, 12-pixel array that was developed in a 22 nm CMOS technology and it covers a band from 200 GHz to 600 GHz. A quasi-optical (QO)...
conference paper 2022
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Ozzola, R. (author), Geng, J. (author), Llombart, Nuria (author), Freni, A. (author), Cavallo, D. (author), Neto, A. (author)
A Volumetric Method of Moments accelerated by means of iterative solvers combined with FFT matrix-vector products has been presented. The method allows analyzing small lens antennas with their integrated feeds efficiently since different structures and geometries can be studied with the same discretization, just by adding the material...
conference paper 2022
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Ozzola, R. (author), Cavallo, D. (author), Freni, Angelo (author), Llombart, Nuria (author), Neto, A. (author)
The number of independent links that can be hosted by an antenna platform for Line-of-Sight (LoS) communications is limited by its physical size and the interference between the beams associated with different users. For large-size platforms, the interference can be reduced by compromising the aperture efficiency, and this trade-off is the...
journal article 2022
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Cavallo, D. (author)
Connected slot arrays with artificial dielectric layers (ADLs) are a type of wideband wide-scanning arrays with several favorable properties. A key advantage is the high front-to-back ratio provided by the artificial dielectric, which allows to reduce the distance between the radiating slots and the ground plane. This results in low-profile...
conference paper 2022
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van Berkel, S.L. (author), Malotaux, E.S. (author), De Martino, C. (author), Spirito, M. (author), Cavallo, D. (author), Neto, A. (author), Llombart, Nuria (author)
A complete system modeling and characterization of a wideband differential terahertz (THz) direct detector, integrated in a commercial CMOS technology, is presented. The detector consists of a recently developed double leaky-slot lens antenna that operates from 200 to 600 GHz in combination with a differential Schottky barrier diode (SBD) direct...
journal article 2021
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Van Katwijk, Alexander J. (author), Neto, A. (author), Toso, Giovanni (author), Cavallo, D. (author)
We present the unit cell design of a wideband wide-scanning phased array operating in both Ku- and Ka-bands, for satellite communication applications. The radiating elements are dual-polarized connected slots loaded with an artificial dielectric superstrate, acting as a wide angle impedance matching (WAIM) structure. The design of the multi...
conference paper 2020
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Tokan, F. (author), Cavallo, D. (author), Neto, A. (author)
Three-dimensional body scanning systems are increasingly used in sensitive public areas such as airports. By providing a high resolution image of a person from all sides, it is possible to detect potential metallic, ceramic and explosive threats. For these systems, it is essential to design broadband antennas with a fan beam, highly directional...
journal article 2020
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