A5014146942- Advanced Antenna and Metasurface Technologies
- Antenna Design and Analysis
- Metamaterials and Metasurfaces Applications
- Microwave Engineering and Waveguides
- Electromagnetic Scattering and Analysis
- Antenna Design and Optimization
- Energy Harvesting in Wireless Networks
- Electromagnetic Simulation and Numerical Methods
- Satellite Communication Systems
- Electromagnetic Compatibility and Measurements
- Optical Coatings and Gratings
- Advanced Materials and Mechanics
Wave Up (Italy)
2017-2024
University of Siena
2010-2019
Scripps Institution of Oceanography
2015
University of California, San Diego
2015
European Space Research and Technology Centre
2013-2014
This paper presents design and analysis methods for planar antennas based on modulated metasurfaces (MTSs). These operate an interaction between a cylindrical surface-wave (SW) excited by isotropic TM radiator, MTS having spatially equivalent impedance. The is realized using sub-wavelength patches printed grounded slab, thus resulting in structure with light weight compact volume. Both features are appealing characteristics space applications. introduces the first time impedance-based...
Metasurfaces constitute a class of thin metamaterials, which are used from microwave to optical frequencies create new antennas and devices. Here, we propose the use variable-impedance metasurfaces for transforming surface or guided waves into different wavefield configurations with desirable properties. We will shortly refer this metasurface-driven transformation as “metasurfing.” Metasurfing can be obtained by an appropriate synthesis inhomogeneous metasurface reactance that allows local...
Different kinds of spiral planar circularly polarized (CP) antennas are presented. These based on an interaction between a cylindrical surface-wave excited by omnidirectional probe and inhomogeneous surface impedance with pattern. The transforms bounded wave into leaky almost broadside radiation. problem is studied adiabatically matching the local 2D solution modulated surface-impedance to actual surface. Analytical expressions derived for far-field radiation pattern; this basis, universal...
Theory, design, realization and measurements of an X-band isoflux circularly polarized antenna for LEO satellite platforms are presented. The is based on a metasurface composed by dense texture sub-wavelength metal patches grounded dielectric slab, excited surface wave generated coplanar feeder. extremely flat (1.57 mm) light (less than 1 Kg) represents competitive solution space-to-ground data link applications.
An effective synthesis procedure for planar antennas realized with nonuniform metasurfaces (MTSs) excited by a point source is presented. This potentiates previous formulations introducing control of the amplitude aperture field while improving polarization and phase performances. The class MTS we are dealing using subwavelength patches different dimensions printed on grounded slab, illuminated transverse magnetic source. These based interaction between cylindrical surface-wave periodic...
Abstract Metasurfaces are thin two-dimensional metamaterial layers that allow or inhibit the propagation of electromagnetic waves in desired directions. For example, metasurfaces have been demonstrated to produce unusual scattering properties incident plane guide and modulate surface obtain radiation properties. These employed, for create innovative wireless receivers transmitters. In addition, recently proposed confine waves, thereby avoiding undesired leakage energy increasing overall...
Abstract This paper presents new designs, implementation and experiments of metasurface (MTS) antennas constituted by subwavelength elements printed on a grounded dielectric slab. These exploit the interaction between cylindrical surface wave (SW) wavefront an anisotropic impedance boundary condition (BC) to produce almost arbitrary aperture field. They are extremely thin excited simple in-plane monopole. By tailoring BC through shaping elements, these can be largely customized in terms beam...
We explore various possibilities for designing multibeam antennas using a single metasurface (MTS) aperture. Both single-source and multisource feeding schemes are considered. For the case, two approaches investigated. In first one, MTS aperture is divided into several angular sectors, each one devoted to formation of beam in given direction. second approach, whole shared by superposition individual modulations, which correspond those required obtain beams desired set directions. It shown...
This paper presents a new theory for analyzing the leaky-wave (LW) mechanism supported by planar metasurfaces (MTSs) described continuous, anisotropic, nonuniform, locally periodic boundary conditions (BCs), and excited vertical dipole at interface. These BCs well represent dense distribution of subwavelength metal patches infinitesimal thickness, printed on grounded slab. We denote succinctly this theoretical formulation as flat optics LWs. is based an adiabatic, asymptotic form Floquet...
Different types of efficiencies are introduced for metasurface (MTS) antennas based on single point-source excitation: 1) the feed efficiency ε <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">feed</sub> is power delivered by to surface wave (SW) over input power; 2) tapering xmlns:xlink="http://www.w3.org/1999/xlink">tap</sub> quantifies deviation with respect a uniform illumination; 3) conversion...
Transformation Optics asks Maxwell's equations what kind of electromagnetic medium recreate some smooth deformation space.The guiding principle is Einstein's covariance: that any physical theory must take the same form in coordinate system.This requirement fixes very precisely required medium.
Realizations and measurements of broadside-beam circularly polarized anisotropic metasurface antennas are presented. The validity the design methodology proposed in a previous paper is here experimentally demonstrated by developing 28-dBi transmitting antenna 22-dBi receiving for space-to-ground links at X-band. High polarization purity obtained using simple vertical (i.e., linearly polarized) monopole as feeder, thus providing experimental evidence fact that surface increases aperture...
We present analytical expressions for the frequency bandwidth of gain broadside-beam metasurface (MTS) antennas. These antennas are based on a transformation between cylindrical surface-wave (SW) and leaky-wave through interaction with periodically modulated MTS. The latter is realized by using subwavelength patches different dimensions printed grounded slab. demonstrate that, an appropriate choice modulation index, relative inversely proportional to antenna radius in terms wavelength,...
Design, realization, and measurements of an X-band antenna for data downlink (DDL) from low Earth orbit (LEO) satellites are presented. This has isoflux radiation pattern operates in dual circular polarization with cross-polar discrimination (XPD) higher than 18 dB on the operational bandwidth. Two solutions first proposed: one realized by a metasurface strips printed dielectric slab another concentric metallic corrugations. Starting basic scattering mechanism self-complementary ring-type...
This paper describes various possibilities for designing multibeam antennas using a single metasurface (MTS) aperture. Both single-source and multi-source feeding schemes are considered. For the case, two approaches investigated: i) division of aperture in several angular sectors (one per beam) ii) superposition individual modulations required to obtain beams desired directions. A configuration based on scheme is also tailored by modulation patterns. Numerical results Method Moments...
In this paper, we describe an efficient method for the full-wave simulation of printed antennas based on metasurfaces whose texturing is realized by means elliptical patches. The fast solution integral equation discretized using moment with only two entire domain basis functions each patch. two-dimensional version Fast Multipole introduced to accelerate linear system derived from analysis method. Numerical results are provided demonstrate effectiveness proposed approach.
This paper discusses about design, analysis and optimization aspects of metasurface antennas. The design procedure metasurfaces for the realization shaped beam antennas application examples are presented. For fast a suitable use in an loop customized efficient full wave tool has been developed within 3DAMxLAD module ADF-EMS (Antenna Design Framework - Electromagnetic Satellite).
Artificial surfaces for antenna applications are discussed. The paper is focused on antennas LEO satellite application and a circularly polarized isoflux shaped beam based metasurface presented with numerical results. Potentialities of the metasurfing concept to reconfigurable also