Abstract: A structure includes a first material, the first material including an artificially structured array of elements, the first material further being arranged in a pattern to at least partially form a photonic band gap in a band gap frequency range. The first material has an effective permeability or an effective permittivity in the band gap frequency range that is determined at least partially by the elements in the array.

Abstract: Surface scattering antennas on curved manifolds provide adjustable radiation fields by adjustably coupling scattering elements along a wave-propagating structure.

Abstract: Surface scattering antennas with lumped elements provide adjustable radiation fields by adjustably coupling scattering elements along a wave-propagating structure. In some approaches, the surface scattering antenna is a multi-layer printed circuit board assembly, and the lumped elements are surface-mount components placed on an upper surface of the printed circuit board assembly. In some approaches, the scattering elements are adjusted by adjusting bias voltages for the lumped elements. In some approaches, the lumped elements include diodes or transistors.

Abstract: Described embodiments include a system, method, and apparatus. The system includes an antenna comprising a sub-Nyquist holographic aperture configured to define selectable arbitrary complex radiofrequency electromagnetic fields on a surface of the antenna. A mapping engine models an environment within a space radiateable by the antenna. The environment includes a target device and a human being. An optimization circuit selects responsive to the model of the environment a power transmission regime. The power transmission regime includes radiation pattern shaped to wirelessly transfer electromagnetic power from the antenna to the target device without exceeding a radiation exposure limit for humans. A gain definition circuit selects a complex radiofrequency electromagnetic field implementing the selected power transmission regime from the at least two selectable arbitrary complex radiofrequency electromagnetic fields.

Abstract: Described embodiments include an antenna, method, and an apparatus. The antenna includes a sub-Nyquist holographic aperture configured to define at least two selectable, arbitrary complex radiofrequency electromagnetic fields on a surface with tangential wavenumbers up to the free-space wavenumber (k0). In an embodiment, the antenna is configured to beam radiofrequency electromagnetic power. In an embodiment, the antenna is configured to transfer radiofrequency electromagnetic power.

Abstract: Described embodiments include a system, method, and apparatus. A system includes an antenna comprising a sub-Nyquist holographic aperture configured to define selectable arbitrary complex radiofrequency electromagnetic fields on a surface of the antenna. A path analysis engine tests power transmission pathways from the antenna to a target device located in an environment within a space radiateable by the antenna. The environment includes a human being. An optimization circuit selects responsive to the tested power transmission pathways a power transmission regime. The regime includes an electromagnetic radiation pattern shaped to transfer radiofrequency electromagnetic power from the antenna to the target device without exceeding a radiation exposure limit for humans. A gain definition circuit selects a complex radiofrequency electromagnetic field implementing the selected power transmission regime from the at least two selectable, complex radiofrequency electromagnetic fields.

Abstract: Described embodiments include an antenna, method, and an apparatus. The antenna includes a sub-Nyquist complex-holographic aperture configured to define at least two selectable, arbitrary complex radiofrequency electromagnetic fields on a surface with tangential wavenumbers up to 2? over the aperture element spacing (k_apt=2?/a).

Abstract: Described embodiments include a system and method. A digital imaging device is configured to capture images of a region of a contact between a wheel of a terrestrial vehicle and a surface (“contact region”). A correlator is configured to correlate a first digital image of the contact region captured at a first time with a second digital image of the contact region captured at a second time. A kinematics circuit determines an incremental slide or slip of the wheel relative to the surface. A fraction status circuit combines at least two instances of the incremental slide or slip into data indicative of a slide or slip by the terrestrial vehicle relative to the surface. A communications circuit outputs an electronic signal indicative of the data indicative of a slide or slip by the terrestrial vehicle.

Abstract: A pedestrian warning system monitors an attention level of a pedestrian and alerts the pedestrian of traffic areas or detected vehicles.