The University of Texas System

USA As Represented by Secretary of the Navy

University of Pennsylvania

Northeastern University

3m Innovative Properties Company

Andrea Alu

Craig R Schardt

Bing Hao

Matthew S Byrne

Nader Engheta

Karl K Stensvad

Dimitrios Sounas

Hussein Esfahlani

Ahmed Kord

Jason Christopher Soric

Nicholas Estep

Matteo Rinaldi

Cristian Cassella

Mikhail A Belkin

George Palikaras

Adam Overvig

Alessandro Salandrino

Xuexue Guo

Yakir Hadad

Jongwon Lee

Mykhailo Tymchenko

Romain Fleury

Efthymios Kallos

Supercoupling waveguides are provided in which acoustic impedance at an acoustic input port matches the acoustic impedance at an acoustic output port, where the acoustic path extending from the acoustic input port to the acoustic output port has a variable length. The supercoupling waveguides may be used in methods of sensing and measuring, and may be incorporated into sensors.

Supercoupling waveguides, and methods for making and using same

Supercoupling power dividers are provided, in which acoustic impedance at an acoustic input port matches the combined acoustic impedance at two or more acoustic output ports, and the phase of the input signal matches the combined phases of the two or more acoustic output ports. Methods for achieving impedance matching using a uniform-phase acoustic power divider are also provided. The devices and methods achieve acoustic supercoupling without requiring embedded membranes or resonators.

Supercoupling power dividers, and methods for making and using same

A magnet-free non-reciprocal device realized using modulated filters. The device includes one or more filters in one or more branches, where each branch connects two ports or a port and a central node. The poles and zeros of each of the first, second and third filters are modulated in time such that degenerate modes at each pole and zero is split thereby destructively interfering at one or more output ports and adding up at another output port allowing non-reciprocal transmission, isolation and/or non-reciprocal phase shift. The device is able to realize a magnet-free full-duplex communication scheme implementing a magnet-free circulator for radio frequency cancellation or a magnet-free isolator or gyrator.

Magnetless non-reciprocal devices using modulated filters

A microelectromechanical resonant circulator device is providing, having a substrate, and at least three electrical ports supported on the substrate. At least three electromechanical resonator elements are connected with associated switch elements and an associated port. The switch elements are operative to provide commutation over time of the electromechanical resonator elements.

Microelectromechanical resonant circulator

A communication system that reduces the mutual influence of antennas operating in similar or different frequency bands. The communication system includes a first and a second antenna operating in a first and a second frequency band, respectively, and placed in close proximity to each other. The first antenna is covered by a conformal mantle metasurface with anti-phase scattering properties thereby cancelling the scattering in the second frequency band. The conformal mantle metasurface consists of a patterned metallic sheet comprising slits both in an azimuthal and a vertical direction to reduce both vertical and horizontal polarization scattering. When the first antenna is a low-band dipole antenna and when the second antenna is a high-band dipole antenna, the conformal mantle metasurface reduces the low-band blockage without disrupting the performance of both antennas in terms of radiation pattern and impedance matching.

Dual-polarized, broadband metasurface cloaks for antenna applications

A non-reciprocal device using a space-time modulation scheme. By applying the space-time modulation scheme, reciprocity in radiation and scattering scenarios is prevented. Such a scheme utilizes a linear system with simple, compact and inexpensive electronic components compared to the current use of bulky duplexers and non-reciprocal magnet based phase shifters to provide non-reciprocity. One such linear system involves traveling-wave antennas loaded with voltage dependent capacitors that are modulated in space and time thereby allowing the antenna to transmit with high directivity in a certain direction and not receive from that direction. Another linear system involves a resonant metasurface characterized by transverse spatiotemporal gradients, where the spatiotemporal gradients include periodically modulated impedances thereby causing a non-reciprocal transmission response. In this manner, a signal that propagates and impinges on the surface at a given direction will be fully transmitted while a signal propagating from the complementary direction will be fully reflected.

Eliminating reciprocity constraints in radiating and scattering systems with spatio temporal modulation

A non-reciprocal device incorporating metamaterials which exhibit non-reciprocity through angular momentum biasing. The metamaterial, such as a ring resonator, is angular-momentum biased. This is achieved by applying a suitable mechanical or spatio-temporal modulation to resonant inclusions of the metamaterial, thereby producing strong non-reciprocity. In this manner, non-reciprocity can be produced without requiring the use of large and bulky magnets to produce a static magnetic field. The metamaterials of the present invention can be realized by semiconducting and/or metallic materials which are widely used in integrated circuit technology, and therefore, contrary to magneto-optical materials, can be easily integrated into the non-reciprocal devices and large microwave or optical systems. The metamaterials of the present invention can be compact at various frequencies due to the enhanced wave-matter interaction in the constituent resonant inclusions. Additionally, by using the metamaterials of the present invention, the power consumed in the biasing network is drastically reduced.

Magnetic-free non-reciprocal devices exhibiting non-reciprocity through angular momentum biasing

A nonlinear metasurface structure including a multi-quantum-well layer designed for a nonlinear response for a desired nonlinear optical process and an array of nanoantennas coupled to the intersubband transitions of the multi-quantum-well layer. Each nanoantenna in the array is designed to have electromagnetic resonances at or close to all input and output frequencies of a given nonlinear optical process. Nanoantennas allow efficient coupling of any incident and outgoing light polarizations to intersubband transitions. Nanoantennas may further provide significant field enhancement in the multi-quantum-well layer. As a result, the nonlinear metasurface structure can be designed to produce a highly nonlinear response for any polarization and angle of incidence of incoming and outgoing waves in a nonlinear optical process. Due to their very larger nonlinear response, efficient frequency conversion can be produced in these metasurfaces without the stringent phase-matching constraints of bulk nonlinear crystals.

Nonlinear metasurfaces based on plasmonic resonators coupled to intersubband transitions

A non-reciprocal acoustic device that accomplishes non-reciprocity via linear or angular-momentum bias. The non-reciprocal acoustic device includes an azimuthally symmetric or planar acoustical cavity (e.g., ring cavity), where the cavity is biased by imposing a circular or linear motion of a gas, a fluid or a solid medium filling the cavity. Acoustic waveguides are connected to the cavity or the cavity is excited from the surrounding medium. A port of this device is excited with an acoustic wave. When the cavity is biased appropriately, the acoustic wave is transmitted to one of the other acoustic waveguides while no transmission of the acoustic wave occurs at the other acoustic waveguides. As a result, linear non-reciprocity is now realized in acoustics without distorting the input signal or requiring high input power or bulky devices.

Non-reciprocal acoustic devices based on linear or angular momentum biasing

Circuits and circuit elements adapted to function at optical or infrared frequencies are made from plasmonic and/or nonplasmonic particles disposed on a substrate, where the plasmonic and nonplasmonic particles have respective dimensions substantially smaller than a wavelength of an applied optical or infrared signal. Such particles are deposited on a substrate in a variety of shapes and sizes from a variety of plasmonic and/or nonplasmonic materials so as to form resistors, capacitors, inductors and circuits made from combinations of these elements.

Growing community of inventors

Austin, TX, United States of America

Andrea Alu