Abstract: Designs and control techniques for passive Multiple-Input Multiple-Output (pMIMO) surfaces are provided. An example array of reconfigurable reflective elements includes a plurality of unit cells each comprising a cross-slot radiating element, a first varactor diode disposed across a first end of the cross-slot radiating element and configured to control polarization in a first plane, and a second varactor diode disposed across a second end of the cross-slot radiating element and configured to control polarization in a second plane, and a controller coupled to the first varactor diode and the second varactor diode and configured to provide control signals to the first varactor diode and the second varactor diode to vary a direction of a reflected signal.

Abstract: Aspects of the disclosure related to devices, wireless communication apparatuses, methods, and other aspects of passive multiple input multiple output. In some aspects, an apparatus is provided that includes a first radio frequency (RF) transmission line having a first terminated with a quarter wavelength grounded transmission line, and a first array of antennas including a plurality of antenna elements. The apparatus also includes a switch array including a corresponding switch for each antenna element of the plurality of antenna elements of the first array of antennas, to selectively connect each antenna element to the first RF transmission line, and path lengths selectable by the switches at half wavelength distances for passive transmission. The apparatus also includes or more lens elements configured to modify wireless inputs signals to the first array of antennas and to modify wireless output signals from the first array of antennas.

Abstract: Techniques for providing radio-frequency signals to a region of interest for a living-objection protection (LOP) system are provided. An example base wireless power transfer system includes a power-coupling element and a power transfer circuitry configured to provide energy to the power-coupling element to produce a magnetic field, and a living-object protection subsystem including an antenna configured to transmit a first radio-frequency (RF) signal with a main beam directed away from the power transfer circuitry and to receive a second RF signal, the antenna including a radiating element and a reflector with the reflector being disposed between the radiating element and the power transfer circuitry and comprising a metal sheet disposed over an area, the metal sheet defining at least one opening within the area and between the radiating element and the power transfer circuitry.

Abstract: Techniques for providing radio-frequency signals to a region of interest for a living-objection protection (LOP) system are provided. An example base wireless power transfer system includes a power-coupling element and a power transfer circuitry configured to provide energy to the power-coupling element to produce a magnetic field, and a living-object protection subsystem including an antenna configured to transmit a first radio-frequency (RF) signal with a main beam directed away from the power transfer circuitry and to receive a second RF signal, the antenna including a radiating element and a reflector with the reflector being disposed between the radiating element and the power transfer circuitry and comprising a metal sheet disposed over an area, the metal sheet defining at least one opening within the area and between the radiating element and the power transfer circuitry.

Abstract: Systems and methods which provide enhanced isolation for receivers using relatively simple and inexpensive modifications or additional circuitry at a receiving station. Embodiments augment a primary antenna of a receiving station with a correlated heterogeneous antenna element. Augmented antenna systems of embodiments provide an appreciable increase in front-to-back isolation with respect to desired signals received at a receiving station. Such augmented antenna systems are particularly useful in a high interference environment, such as an interference limited environment as may be experienced at the edge of two Single Frequency Networks (SFNs). For example, embodiments of an augmented antenna system may be utilized in situations in which positive carrier to noise ratio (C/N) conditions are present (e.g., more signal than noise is present in the desired signal and more signal than noise is present in the interfering signal).

Abstract: A method and an apparatus for a reconfigurable antenna are provided. The apparatus is a reconfigurable antenna including a patch antenna and one or more parasitic slots. The patch antenna includes a first conductor plane and a second conductor plane. The second conductor plane is configured to provide a ground plane for the first conductor plane. The reconfigurable antenna further includes a first parasitic slot of the one or more parasitic slots formed in the second conductor plane. The first parasitic slot of the one or more parasitic slots is formed by a first set of two opposing portions of the second conductor plane. The first set of two opposing portions is separated by a first cutout in the second conductor plane. The reconfigurable antenna further includes a first switch configured to enable or disable the first parasitic slot of the one or more parasitic slots.

Abstract: A birefringent reflectarray having a planar metasurface containing metallic patches of subwavelength dimension is provided. The reflectarray is capable of simultaneously reflecting, concentrating, and splitting incident infrared light into two orthogonal linearly polarized reflections, and transforms the phase front of an incoming polarized light to a desired phase for the two reflections. Also provided is an optical modulator having a metasurface containing layers of nanoantennas of subwavelength dimension, and capable of modulating the phase and amplitude of light scattered from the modulator. The optical modulator has ability to perform computation through processing of light.