相关论文: Broadband Acoustic Collimation and Focusing using …

Luneburg lens is a gradient index lens that focuses the incoming wave on the opposite side of the lens without aberration. We developed a two-dimensional acoustic Luneburg lens by changing the refractive index of the medium in the lens. It…

In this paper, a novel structural Luneburg lens with local resonators is proposed. This lens allows for the realization of subwavelength focusing in low frequency range. The lens is achieved by graded refractive index from the lens centre…

Luneburg lens is a symmetric gradient-index lens with a refractive index that increases from the outer surface to the center in a radial manner. It has the ability to focus and collimate waves, which makes it useful for energy harvesting,…

A three-dimensional acoustic Luneburg meta-lens has the advantage of refracting sound waves for all incident angles and focusing higher sound pressure compared to a two-dimensional lens. The lens made of plastic with a diameter of 120 mm…

This paper proposes an acoustic beam splitter based on acoustic Luneburg lens. A two-dimensional acoustic Luneburg lens with gradient refractive index is achieved to provide a practical realization for the acoustic beam splitter. The…

This paper investigates the acoustic Luneburg Lens (ALL) as a design framework for guiding acoustic wave propagation. In this study, we propose to develop an acoustic waveguide based on the characteristics of both acoustic wave focusing and…

We report ultrasound beam steering based on 2D and 3D flattened acoustic metamaterial Luneburg lenses at 40 kHz. The effective properties of the lenses are obtained by using the quasi-conformal transformation (QCT) technique and solving the…

Applying the directionality of a Luneburg lens, a sound reception system for ships is designed. A two-dimensional acoustic Luneburg lens which is made of 253 acrylic pipes of different radii which control the refractive index is used. It…

Lenses are typically based on refractive index profiles derived from the geometric approximation of high-frequency waves, yet the critical issue of impedance mismatch is often neglected. Mismatched devices suffer from unwanted reflections…

In this paper we present the design of a flat-base Luneburg type of lens antenna, designed for wide angle scan. The antenna consists of a 11-layer lens, fed at its base by a 6x6 array of waveguides. The lens is broadband and has a high…

In this paper, a novel gradient index (GRIN) acoustic metamaterial is proposed based on the concept of optical modified generalized Luneburg lens (MGLL). With the MGLL, double-foci and high energy density between the two foci can be…

Acoustic metamaterials have become a novel and effective way to control sound waves and design acoustic devices. In this study, we design a 3D acoustic metamaterial lens (AML) to achieve point-to-point acoustic communication in air: any…

In this paper, a compact wideband dual-polarized Luneburg lens antenna (LLA) with reduced anisotropy and improved impedance matching is proposed in Ka band with a wide 2D beamscanning capability. Based on transformation optics, the…

Recent studies have introduced a new class of two-dimensional acoustic metamaterials whose dispersion and propagation properties results from the use of geometric inhomogeneities in the form of Acoustic Black Holes (ABH). The ABH is an…

Backscatter communications is attractive for its low power requirements due to the lack of actively radiating components; however, commonly used devices are typically limited in range and functionality. Here, we design and demonstrate a…

In this paper, a novel gradient index (GRIN) structural lens based on the concept of generalized Luneburg lens (GLL) is proposed. This lens allows for the realization of double foci and localization of energy flow between the two focal…

We propose and demonstrate a compact acoustic retroreflector that reroutes probing signals back towards the source with minimal scattering. Gradient refractive index (GRIN) acoustic metamaterials, based on Archimedean spiral structures, are…

The correction of the aberration of transcranial focused ultrasounds is a relevant issue for enhancing various non-invasive medical treatments. Emission through multi-element phased arrays has been the most widely accepted method to reduce…

Acoustic lenses are employed in a variety of applications, from biomedical imaging and surgery, to defense systems, but their performance is limited by their linear operational envelope and complexity. Here we show a dramatic focusing…

In integrated photonic circuits, silicon-on-insulator waveguides with different geometries have been employed to realize a variety of components. Therefore, efficient coupling of two different waveguides is crucial. In this paper, focusing…