An acoustic metasurface carpet cloak based on membrane-capped cavities is proposed and investigated numerically. This design has been chosen for allowing ultrathin geometries, although adapted to airborne sound frequencies in the range of 1 kHz ($\ensuremath{\lambda}\ensuremath{\approx}30$ cm), surpassing designs reported literature terms thinness. A formulation generalized Snell's laws first proposed, mapping directions incident reflected waves phase function. relation then applied achieve...

It has been shown that acoustic waves with helical wavefronts can carry angular momentum, which be transmitted towards a propagating medium. Such wave field achieved by using planar array of electroacoustic transducers, forming given spatial distribution phased sound sources produce the desired wavefronts. Here, we introduce technique to generate vortices, based on passive metasurface concept. The proposed is composed space-coiled cylindrical unit cells transmitting pressure controllable...

In this letter, a compact single-layer, single-feed, dual-frequency microstrip antenna with high frequency ratio is proposed. This has broadside and symmetrical radiation patterns suitable for space-borne applications. The prototype was fabricated on Rogers RT/duroid 5880 substrate relative permittivity of 2.2 thickness 1.58 mm. dual-band behavior achieved by shorting pin at 1.7-1.706 8.011-8.277 GHz the 4.75. addition, miniaturized 46% compared to conventional rectangular patch.

Abstract When sound interacts with geometrically asymmetric structures, it experiences coupling between pressure and particle velocity, known as Willis coupling. While in most instances this phenomenon is perturbative nature, tailored asymmetries combined resonances can largely enhance it, enabling exotic acoustic phenomena. In these systems, obeys reciprocity, imposing an even symmetry of the coefficients respect to time reversal impinging wave vector, which translates into stringent...

Abstract The optical dispersive prism is a well-studied element, which allows separating white light into its constituent spectral colors and stands in nature as water droplets. In analogy to this definition, the acoustic should be an device with capability of splitting broadband wave Fourier components. However, due acoustical materials well design fabrication difficulties, there neither any natural counterpart prism, nor artificial reported so far exhibiting equivalent behaviour. Here,...

Metasurfaces are ultrathin planar arrays of carefully tailored subwavelength particles that enable agile and flexible manipulation the impinging waves. Originally introduced in optics, their application to acoustic waves has recently opened exciting opportunities for exotic sound control. In conventional inclusions, interactions with pressure velocity decoupled, limiting functionalities them can achieve. While coupling between these two quantities symmetry-breaking known as Willis coupling,...

A transmission-line acoustic metamaterial is an engineered, periodic arrangement of relatively small unit-cells, the properties which can be manipulated to achieve anomalous physical behaviours. These exotic open door practical applications, such as leaky-wave antenna, through implementation radiating channels along metamaterial. In transmitting mode, a antenna capable steering sound waves in frequency-dependent directions. Used reverse, presents well defined direction-frequency behaviour....

Funneling acoustic waves through largely mismatched channels is of fundamental importance to tailor and transmit sound for a variety applications. In electromagnetics, zero-permittivity metamaterials have been used enhance the coupling energy in out ultranarrow channels, based on phenomenon known as supercoupling. These metamaterial can support total transmission complete phase uniformity, independent channel length, despite being geometrically with their input output ports. field acoustics,...

In the last years, number of studies carried out in field acoustic metamaterials has significantly increased. year 2009, our group proposed a concept composite right/left hand transmission line (CRLH-TL) metamaterial, consisting waveguide periodically loaded with membranes along duct, and transverse open channels (denoted "stubs"). It then paved way to antenna applications among which "Acoustic Leaky-Wave Antenna". As, these antennas have very special properties such as frequency-dependant...

Materials with properties that can be described by a near-zero index of refraction have received significant attention in the fields electromagnetics, optics, and acoustics, due to their extraordinary capabilities wave manipulation. It was recently demonstrated theoretically experimentally acoustic waves could manifest near-zero-index propagation based on effective compressibility waveguide channel approaching zero. In turn, this allows tunneling nearly infinite wavelength (or equivalently,...

Funneling acoustic waves through largely mismatched channels is of fundamental importance to tailor and transmit sound for a variety applications. In electromagnetics, zero-permittivity metamaterials have been used enhance the coupling energy in out ultranarrow channels, based on phenomenon known as supercoupling . These metamaterial can support total transmission complete phase uniformity, independent channel length, despite being geometrically with their input output ports. field...

Acoustic metasurfaces have gained popularity for their capability to tailor the phase front of transmitted and reflected waves. While most researches conducted in this topic are spinning around different applications peculiar physics these surfaces, study constituent elements is still missing. Here, we introduce a new labyrinthine type unit-cell engineering wave front. Despite complexity shape, structure very easy design. Moreover, it based on well defined mathematical formula which...

Recent studies have focused on developing metamaterials for acoustic applications, inspired by electromagnetics concepts. The leaky-wave antenna is amongst the most investigated. Despite unfavourable properties of conventional matter and structures with respect to sound dispersion radiation, interesting engineering processes been recently proposed that are likely allow such peculiar properties. After presenting developed one-dimensional design, this paper discusses two pioneering...

In this article we make an analogy between Electromagnetic and Acoustic transmission-line modelling. Then use to introduce acoustic metamaterials finally the leaky-wave antenna on basis of previous steps. The proposed has frequency scanning capability like its electromagnetic counterpart directivity depends length antenna.

Epsilon-near-zero supercoupling is a widely-researched topic in electromagnetics. This phenomenon takes advantage of media with near-zero dielectric permittivity to build waveguide coupling channels which can, principle, support unitary transmission and complete phase uniformity, independent the length height channel. In this effort, we present possibility that an analogous, extraordinary coupled-mode exists acoustics, call compressibility-near-zero (CNZ) supercoupling. Prior works have...

Materials with properties which can be described by a near-zero index have received much attention in the fields of microwave electromagnetics, optics, and acoustics, due to their extraordinary capabilities wave manipulation. It was recently demonstrated, theoretically experimentally, that acoustic media support near-zero-index propagation, effective compressibility waveguide channel approaches zero. In principle, this allows complete tunneling waves nearly infinite wavelength (or...

The most straightforward way to design artificial structures is use periodicity and leverage its potential mathematical physical consequences our favor. However, strict periodicity, which usually employed in designing materials, not practically feasible often some degrees of randomness are introduced the fabrication process, degrade performance. In this presentation, using Furstenberg theory on product random matrices Monte Carlo simulations we explore effect transmission performance...