Abstract: A solar energy collector includes a prism coupled waveguide and a cladding material layer coextensive with the waveguide core. Photovoltaics (PVs) are disposed within the cladding layer, with the PVs active in at least two wavelength ranges. The PVs are further spaced apart depending upon their active wavelength range. The cladding layer may include two or more material layers of at least two different dielectric constants. In that arrangement, the PVs are further grouped such that the PVs disposed in a first one of the cladding layers has a different active wavelength range than an active wavelength range of the PVs disposed in a second cladding layer.

Abstract: A solar energy collector includes a planar waveguide formed of multiple material layers having at least two different dielectric constants. Two or more dichroic filters disposed within the waveguide core, and two or more minors are also disposed within the waveguide core. At least one optical to electrical detector positioned in alignment with each of the dichroic filters, and at least one optical to electrical detector is aligned with each of the mirrors. The dichroic filter may be formed from a plurality of material layers.

Abstract: System and methods for detecting substances such as explosives via the nuclear quadrupole resonance effect. We observe that the nuclear quadrupole resonances of explosives located within a cavity portal involve continuous Rabi transitions which are nonlinear processes since stimulated emission occurs. In other words, where there are no resonances caused by the presence of an explosive, high average power and low average power measurements should be identical. However, when resonances are stimulated by the system, the difference between these two conditions can be compared to determine a correction to measurements made when a person located in the cavity has explosive material on their person, without the need for separate empty portal or elaborate calibration procedures.

Abstract: Nuclear quadrupole resonance measurement using two or more wire loop(s) within a space to define a portal, and driving the wire loop(s) with a baseband digital transmitter generating a chirped or stepped signal, to create a corresponding varying electromagnetic field within the portal. Coherent emissions reflected thereby are detected through a directional coupler feeding the transceiver. The detected coherent emissions are processed with a matched filter to determine presence of a target object within the portal.

Abstract: System and methods for detecting substances such as explosives via the nuclear quadrapole resonance effect. We observe that the nuclear quadrupole resonances of explosives located within a cavity portal involve continuous Rabi transitions which are nonlinear processes since stimulated emission occurs. In other words, where there are no resonances caused by the presence of an explosive, high average power and low average power measurements should be identical. However, when resonances are stimulated by the system, the difference between these two conditions can be compared to determine a correction to measurements made when a person located in the cavity has explosive material on their person, without the need for separate empty portal or elaborate calibration procedures.

Abstract: Dispersive properties of a linear dispersive delay line are retained in a spiral configuration by constraining the radius of curvature depending on a desired propagation mode. The compact form factor spiral can be either a continuous spiral or a piecewise linear approximation. The spiral comprises a highly dielectric waveguide such as titanium dioxide or barium tetratitanate. Preferably, a spacer with a low dielectric constant and a microstrip are disposed on the top surface. The microstrip prevents attenuation of low frequencies, thereby increasing the operating frequency range. A second dielectric spacer and a second microstrip can be deposited on the bottom surface of the waveguide. Alternatively, the bottom surface of the waveguide can face a ground plane. The waveguide can be fed by horns or half-horns.

Abstract: Nuclear quadrupole resonance measurement using two or more wire loop(s) within a space to define a portal, and driving the wire loop(s) with a baseband digital transmitter generating a chirped or stepped signal, to create a corresponding varying electromagnetic field within the portal. Coherent emissions reflected thereby are detected through a directional coupler feeding the transceiver. The detected coherent emissions are processed with a matched filter to determine presence of a target object within the portal.

Abstract: An electromagnetic energy concentrator uses a prism and waveguide with a gap layer of uniform thickness disposed between the prism and a first surface of waveguide. Energy detectors, which may be photovoltaics or miniaturized antenna elements are disposed adjacent to and co-extensive with a second surface of the waveguide. The detectors operate in each of at least two bands; a distance between detectors operating in a given band depends on a wavelength in the given band.

Abstract: A cylindrically symmetric satellite antenna that provides directional and omnidirectional operating modes in a compact form factor. Feed points located at the top of the cylindrical structure provide increased platform isolation. Combining networks, disposed below or within the cylindrical structure, may be replaced with inexpensive baluns composed of coaxial line sections.

Abstract: An compact manpack format antenna operating over a broad bandwidth. In one arrangement, the antenna is formed from a set of five hollow cylindrical conductive elements. Several cylinders provide, for example, a VHF/UHF radiator section and other cylinders form an L-band radiator section. A bottom leg of the L-band section operates as part of the VHF/UHF section via coupling between that lower L-band leg and the VHF/UHF section. This coupling arrangement reduces the required overall physical length of the antenna.

Abstract: Nuclear quadrupole resonance measurement using two or more wire loop(s) within a space to define a portal, and driving the wire loop(s) with a baseband digital transmitter generating a chirped or stepped signal, to create a corresponding varying electromagnetic field within the portal. Coherent emissions reflected thereby are detected through a directional coupler feeding the transceiver. The detected coherent emissions are processed with a matched filter to determine presence of a target object within the portal.

Abstract: Nuclear quadrupole resonance measurement using two or more wire loop(s) within a space to define a portal, and driving the wire loop(s) with a baseband digital transmitter generating a chirped or stepped signal, to create a corresponding varying electromagnetic field within the portal. Coherent emissions reflected thereby are detected through a directional coupler feeding the transceiver. The detected coherent emissions are processed with a matched filter to determine presence of a target object within the portal.

Abstract: A photonic antenna uses a traveling wave fed, surface wave excited, dielectric waveguide. One or more antenna elements are arranged in a line or other array. An optical interconnect is provide by depositing the waveguide structure on the system of antenna elements, and the photodiode detectors on the waveguide, or wafer bonded to the waveguide core. Optical sources are butt coupled to the edge of the waveguide via wafer bonding or as part of a deposition process. The device acts as a free-space optical transceiver embodied in an integrated photonic antenna and waveguide structure, and provides high speed, spectrally broadband response; it also inherently includes an open architecture for implementing Wavelength Division Multiplexing (WDM).

Abstract: A low profile antenna using a cavity-backed central radiating surface surrounded by one or more ground plane surfaces. Passively reconfigurable structure provide frequency dependent coupling between the surfaces. The frequency dependent couplings may be implemented using meander line structures, Variable Impedance Transmission Lines (VITLs), or tunable VITLs that used interspersed electroactive sections.

Abstract: Nuclear quadrupole resonance measurement using two or more wire loop(s) within a space to define a portal, and driving the wire loop(s) with a baseband digital transmitter generating a chirped or stepped signal, to create a corresponding varying electromagnetic field within the portal. Coherent emissions reflected thereby are detected through a directional coupler feeding the transceiver. The detected coherent emissions are processed with a matched filter to determine presence of a target object within the portal.

Abstract: A neuromorphic parallel image processing approach that has five (5) functional layers. The first performs a frequency domain transform on the image data generating multiple scales and feature based representations which are independent of orientation. The second layer is populated with feature based representations. The third layer, an object class recognizer layer, are fused using a neuromorphic parallel processor. Fusion of multimodal data can achieve high confidence, biometric recognition.

Abstract: A leaky travelling wave array of elements provide a broadband radio frequency antenna.

Abstract: A leaky travelling wave array of elements provide a radio frequency antenna.