D. Cavallo
112 records found
1
We present a systematic approach to include the effects of dielectric slabs in artificial dielectric layers (ADLs). Typical implementations of ADLs consist of layers of sub-wavelength metal patches supported by either dielectric slabs or thin dielectric films bonded onto foam spa
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We present an efficient method to analyze a periodic pin-patch structure, consisting of two artificial dielectric layers (ADLs) connected by vertical metal pins. ADLs are made of square metal patches in a periodic lattice and have recently been used as superstrates in antennas an
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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,
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We present an approach to design wideband arrays of connected slots with artificial dielectric layers (ADLs) that allows to take into account both matching and polarization properties. The slots are fed by parallel plate waveguides (PPW s) that are co-designed with the ADLs to re
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The characteristic cross-polarization (X-pol) of wide angle impedance matching (WAIM) structures is investigated. The study considers an ideal linearly polarized current sheet in the presence of various dielectric and artificial dielectric superstrates, analyzed using transmissio
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A review on wideband wide-scanning arrays based on connected slot elements with artificial dielectric superstrates is given. The analysis method to evaluate the active input impedance of the unit cell is described and its application to wideband array designs is discussed. Design
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We present an analytical model to describe arrays of connected slots fed by parallel plate waveguides (PPWs). Connected slot arrays are planar ultra-wideband arrays with wide scanning capability. PPW feeds can be used to reduce the complexity of the unit cell design. However, exi
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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 diffe
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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 co
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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 techno
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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 achi
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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
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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 ca
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Low-Earth Orbit User Segment in the Ku and Ka-Band
An Overview of Antennas and RF Front-End Technologies
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.
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 express
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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 an
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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 w
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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 capabiliti
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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}-directio
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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 coax
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