We show that properly designed mantle cloaks, consisting of patterned metallic sheets placed around cylindrical monopoles, allow tightly packing the same antennas together in a highly dense telecommunication platform. Our experimental demonstration is applied to relevant example two monopole radiators operating for 3G and 4G mobile communications. The are close proximity, separated by 1/10 shorter operational wavelength, and, after cloaking, shown remarkably operate as if isolated...

We present the design of a flat lens, made by conventional material and an epsilon near-zero metamaterial, to plug up aperture short horn antenna, in order achieve radiation performances similar ones corresponding optimum over broad frequency range. Lens operation is based on phase-compensation concept: phase-fronts field propagating along flare propagate with different phase velocities two lens materials, resulting uniform distribution aperture. Starting from theoretical study transmission...

Although cloaks are effective at suppressing the observability of static objects, they can be defeated when in motion. Here we discuss a general technique to cloak motion objects from observers, based on compensating Doppler shift associated with their frequency conversion sustained by spatiotemporally modulated cover. The concept is theoretically and numerically demonstrated system composed planar reflector covered slab. It shown that, for properly selected modulation frequency, composite...

Temporal metamaterials are artificial materials whose electromagnetic properties change over time. In analogy with spatial media and metamaterials, where their smoothly or abruptly space, temporal can exhibit a smooth variation time, realizing non-homogeneous medium, stepwise transition, the version of dielectric slabs multilayer structures. this Letter, we focus our attention on structures, propose synthesis higher-order transfer functions by modeling wave propagation through generalized...

So far, the environment has been considered as a source of fading, clutter, blockage, etc., with detrimental consequences for efficiency and robustness communication systems. However, intense research developed toward beyond-5G communications is leading to paradigm change, in which exploited new degree freedom plays an active role achieving unprecedented system performances. For implementing this challenging paradigm, it recently proposed use intelligent surfaces able control almost at will...

Metasurfaces consisting of electrically thin and densely packed planar arrays subwavelength elements enable an unprecedented control the impinging electromagnetic fields. Spatially modulated metasurfaces can efficiently tailor spatial distribution these fields with great flexibility. Similarly, time be successfully used to manipulate frequency content variations field. In this paper, we present time-modulated reflective that cause a shift radiation, thus realizing artificial Doppler effect...

Time-varying metamaterials are artificial materials whose electromagnetic properties change over time. Similar to a spatial medium discontinuity, sudden in time of the metamaterial refractive index induces generation reflected and refracted light waves. The relationship between incident emerging fields at one temporal interface has been subject investigation earlier studies. Here, we extend study slab, i.e., uniform homogeneous that is present whole space for limited scattering coefficients...

A metasurface (MTS)-based direction of arrival (DoA) estimation method is presented. The exploits the properties space–time modulated reflective metasurfaces to estimate in real-time impinging angle an illuminating monochromatic plane wave. approach makes use amplitude unbalance received fields at broadside frequencies two first-order harmonics generated by interaction between incident wave and metasurface. Here, we first describe analytically how generate desired higher order reflected...

Recently, the use of deflecting covering meta-domes for increasing scanning range a phased array has been proposed. Although promising, this solution still presents some inherent limitations, such as significant reduction broadside gain compared to original array, well complexity implementation due need continuous phase profile. This work aims at proposing technical solutions maximizing meta-dome performance and reducing gain-loss broadside. By properly discretizing engineering profile along...

Conventionally, antennas are reciprocal devices, exhibiting the same properties in transmission and reception. In order to break antenna reciprocity, this letter, we exploit of space-time varying metamaterials, whose dielectric modulated both space time. We propose surround by a cloak that imparts momentum bias electromagnetic field propagating through it. The wave interacts with modulation only one direction, breaking time-reversal symmetry and, thus, reciprocity system. Here, show properly...

In this letter, we propose a magnet-less non-reciprocal isolating system based on time-varying metasurfaces. Two parallel metasurfaces, one for frequency up-conversion and down-conversion by the same amount, are used realizing region of space where incident waves from opposite directions experience an Doppler shift. As result, any device within becomes sensitive to illumination direction, exhibiting different scattering response thus breaking reciprocity. Very importantly, thanks shift...

The development of the next generation wireless systems is bringing renewed attention to physical layer communication link. Indeed, new low-latency requirements cannot be satisfied relying only upon extreme virtualization hardware functions. Moreover, conventional with fixed characteristics and functionalities are not appropriate modern electromagnetic environments, which undergo continuous fast variations. Embedded smartness a required feature for widening range possible responses support...

Temporal metamaterials have been recently exploited as a novel platform for conceiving several electromagnetic and optical devices based on the anomalous scattering response arising at single change or multiple sudden changes in material properties. However, they are difficult to implement realistic scenarios by switching permittivity of time, new strategies achieve time interfaces feasible manner must be identified. In this paper, we investigate possibility realize temporal metamaterial...

As engineered electromagnetic covers based on (space-) time modulated metamaterials and metasurfaces, Doppler cloaks are able to compensate the effect induced by motion of a scatterer, making it appear as if were at rest detecting radar system. Perfect compensation can be theoretically always achieved for any relative velocity direction cloaked scatterer with respect However, still detected from cross section variation especially under oblique incidence illumination. The challenge is,...

In this work, we apply angular momentum-biased metamaterials to break the intrinsic reciprocity of antenna systems, with potential applications satellite communications. We focus our attention on a conical horn exhibiting nonreciprocal response for left-handed and right-handed circularly polarized fields. A metallic screen an annular aperture is placed between feeding waveguide horn. This inclusion loaded modulated capacitors achieve transmittance fields impinging from opposite sides....

Fifth-generation (and beyond) networks are characterized by ever more demanding requirements in terms of speed, bandwidth, and number servable users. Fast reliable access to the main network is mandatory, requiring technologies procedures that ensure high performing cell search initial (IA). Existing phased array antennas (PAAs) limited single beam scanning approach complex feeding systems. In this paper, a beamforming metasurface shifts field manipulation from an electric level...

The use of 5G New Radio (NR) spectrum around 26 GHz is currently raising the quest on its compatibility with well-established Earth Exploration-Satellite Service (EESS), which may be blinded by spurious radiation emitted Above-the-Horizon (AtH) Base Station (BS) antennas. Indeed, AtH grating lobes are often present during cell scanning due to large inter-element spacing in BS array antennas for achieving higher gains a reduced number RF chains. In this letter, we propose an approach based...

Since the dawn of modern optics and electromagnetics, optical prism is one most fascinating elements for refracting light. Exploiting its frequency dispersive behavior, a able to refract different frequencies in directions, realizing polychromatic light rainbows. Recently, thanks their engineerable electromagnetic response, metamaterials have been exploited achieving novel refractive scattering processes, going beyond classical effects. In this Letter, we report on rainbow-like process...

Future wireless systems integrating communication and sensing will require handling an enormous amount of data with extremely low latency. Intense video streaming traffic, pervasive-augmented virtual reality services, advanced haptic–tactile interaction holography-type communications, in fact, reveal a trend towards experience-based networks multi-sense media, which seamless connectivity ultra-high capacity. Using current 5G technologies to take mentioned challenges, might not represent the...

In this study, we investigate the feasibility of designing reconfigurable transmitting metasurfaces through use Drude-like scatterers with purely electric response. Theoretical and numerical analyses are provided to demonstrate that response spherical can be tailored achieve complete transmission, satisfying a generalized Kerker's condition at half their plasma frequency. This phenomenon, which arises from co-excitation dipole quadrupole within scatterer, also exhibits moderate broadband...

In this paper, we consider a dense array of metallic circular patches printed on electrically thin metal-backed dielectric substrate.Since the sub-wavelength dimensions, and substrate can be described in terms lumped capacitance inductance, respectively.Around resonant frequency, structure, known as high-impedance surface, reflects totally an incident electromagnetic wave with zero shift phase.Due to property, it is widely employed antenna systems compact back reflector improved performances...

In this letter, we present the design and experimental realization of an innovative self-filtering low-noise horn antenna. The proposed radiator consists following: a regular WR-62 waveguide connected to antenna, metallic screen with vertical slit placed at section connecting horn, dielectric slab, omega shapes printed on both faces, across slit. goal is reduce bandwidth operation in order self-filter noise captured within antenna band. receiving mode, allow transmission only narrow...

Boosted by the progresses in nanooptics, highly sensitive and label-free optical transducers for sensing applications have been proposed over last years. Among them, plasmonic nanoparticle-based had a great success because their resonant behavior is extremely to changes of local surrounding environment, being interesting candidates real-time measurements diagnoses. Here, we propose employment core-shell super-spherical nanoparticle design new devices. We demonstrate that, thanks this...

This article presents a new design of diverse frequency time modulation for linear frequency-modulated (LFM) radar passive false target spoofing. To realize the modulation, modulated metasurface is designed accordingly, which composed by set elements, each independently time-modulated to specific targets in high-resolution range profile (HRRP) system. Due control scheme element and combined response overall surface, we demonstrate capability several patterns consisting single multiple...