Abstract: A millimeter wave portal imaging system for the detection of concealed weapons, explosives and other contraband items. A preferred millimeter wave imaging system includes a number (such as 64) of millimeter wave detection units each including a frequency scanning antenna and associated electronics. The units are mounted in four posts (16 per post) of a portal structure. Each unit collects frequency dependent beams of millimeter wave radiation from a narrow one-dimensional field of view. The collected radiation from each unit is amplified at the collected frequencies and the amplified signals are separated into frequency dependent bins with a tapped-delay beam-former. These bins are then sampled to produce a one-dimensional image of the antenna field of view. A two dimensional image of a portion of a person passing through the portal is obtained by moving the person (or having the person move) across the field of view of each of the frequency scanning antennas.

Abstract: An automatic celestial navigation system for navigating both night and day by observation of K-band or H-band infrared light from multiple stars. In a first set of preferred embodiments three relatively large aperture telescopes are rigidly mounted on a movable platform such as a ship or airplane with each telescope being directed at a substantially different portion of sky. Embodiments in this first set tend to be relatively large and heavy, such as about one cubic meter and about 60 pounds. In a second set of preferred embodiments one or more smaller aperture telescopes are pivotably mounted on a movable platform such as a ship, airplane or missile so that the telescope or telescopes can be pivoted to point toward specific regions of the sky. Embodiments of this second set are mechanically more complicated than those of the first set, but are much smaller and lighter and are especially useful for guidance of aircraft and missiles.

Abstract: An automatic celestial navigation system for navigating both night and day by observation of K-band or H-band infrared light from multiple stars. A preferred embodiment uses three telescopes with each of the three telescopes rigidly mounted with respect to each other and rigidly mounted on a movable platform such as a ship or airplane with each telescope being directed at a substantially different portion of sky. Telescope optics focuses, onto the pixel array of a sensor, H-band or K-band light from stars in the field of view of each telescope. The system also includes an inclinometer, an accurate timing device and a computer processor having access to cataloged infrared star charts.

Abstract: A concealed weapons and contraband detection system combining metal detection equipment with millimeter wave imaging equipment. The preferred millimeter wave imaging equipment includes at least one millimeter wave frequency scanning antenna for collecting frequency dependent beams of millimeter wave radiation from a narrow one-dimensional field of view. The collected radiation is amplified at the collected frequencies and the amplified signals are separated into frequency dependent bins with a tapped-delay beam-former. These bins are then sampled to produce a one-dimensional image of the antenna field of view. A two dimensional image of a target may be obtained by moving the target across the field of view of the scanning antenna or by moving the antenna in order to scan its line of focus over the target. In preferred embodiments the millimeter wave imager is combined with an active eddy current type metal detector to provide a hybrid system providing important advantages over prior art security systems.

Abstract: A millimeter wave imaging system that includes at least one millimeter wave frequency scanning antenna for collecting frequency dependent beams of millimeter wave radiation from a narrow one-dimensional field of view. The collected radiation is amplified at the collected frequencies and the amplified signals are separated into frequency dependent bins with a tapped-delay beam-former. These bins are then sampled to produce a one-dimensional image of the antenna field of view. A two dimensional image of a target may be obtained by moving the target across the field of view of the scanning antenna. In a preferred embodiment the antenna is only 4.5 inches in length and constructed from WR-10 waveguide with inclined slots cut in one of the narrow walls at 79 mil spacings. This geometry creates a frequency-scanned antenna spanning a 20 degree vertical field of view over a 75.5–93.5 GHz operational band of the sensor, starting at approximately 1 degree below horizontal at 93.

Abstract: Optically controlled micro-electromechanical systems (MEMS) is disclosed. In one embodiment, a MEMS device may include a rotatable mirror having an optical sensor that is in electrical communication with the rotatable mirror via an associated electrode. Electrical potential may be supplied to an appropriately configured optical sensor so that a variable range of voltages may be supplied to the rotatable mirror. In operation, an optical control beam may be directed onto the optical sensor where it may be sampled to determine its optical characteristics (e.g., optical wavelength, light intensity, position, polarization, duty cycle, etc.) The optical sensor may then supply voltage to the rotatable mirror based on the determined optical characteristics of the optical control beam, causing the rotatable mirror to rotate about one or more axes.

Abstract: Method and device for digital x-ray tomosynthesis. Tomographic and/or three-dimensional images of an object are obtained with an x-ray source and a digital x-ray image sensor. The source, object and sensor are positioned relative to each other and attenuation data is obtained for a large number of rays of x-radiation through the object. A special algorithm is provided to convert the data into images. To calculate the images the algorithm uses iterative processes with a least squares type technique but with generalized (as opposed to specific) functions. The algorithm solves for the functions which are the images.

Abstract: A radio frequency amplifier comprising a circuit board having a boundary shaped in the form of an ellipse and two dielectric layers, a first dielectric layer and a second dielectric layer, enclosed by conductive layers. Radio frequency signals are broadcasted from one of the two foci, the first focus, of the elliptically shaped circuit board through the first dielectric layer and separate portions of the signals are collected at the boundary of the first dielectric layer into a plurality of amplifier circuits. The collected portions are amplified separately in the amplifier circuits with radio frequency amplifiers and each of the amplifier circuits provides the same or approximately the same time delay of its collected signal.

Abstract: A porous silicon filter for wavelength multiplexing and de-multiplexing. Preferred embodiments include rugate-type porous silicon filters with pores having continuously varying widths with pore depth an optical cross connect switch. In other preferred embodiments, the pores are filled with a material that changes index of refraction with changes in applied voltage, current or temperature. Important applications of these porous silicon filters are for multiplexing and de-multiplexing in fiber optic communication systems. For example, a preferred embodiment is an all optical fiber optic switch utilizing these filters.

Abstract: A passive millimeter wave imaging system that includes at least one millimeter wave frequency scanning antenna and multiple beam formers collecting narrow beams of millimeter wave radiation from a two-dimensional field of view. The collected radiation is amplified and separated into bins corresponding to various vertical and horizontal beam orientations. In a preferred embodiment the beam formers include one phase processor and 192 frequency processors. Two dimensional images of a target are obtained by the simultaneous detection of signal power within each beam and converting it into pixel intensity level at a rate of 30 frames per second.

Abstract: A wireless cellular communication system in which groups of cellular base stations communicate with a central office via a narrow-band millimeter wave trunk line. The transceivers are equipped with antennas providing beam divergence small enough to ensure efficient spatial and directional partitioning of the data channels so that an almost unlimited number of transceivers will be able to simultaneously use the same millimeter wave spectrum. In a preferred embodiment the trunk line communication link operates within the 92 to 95 GHz portion of the millimeter spectrum. A large number of base stations are each allocated a few MHz portion of a 900 MHz bandwidth of the millimeter wave trunk line. A first transceiver transmits at a first bandwidth and receives at a second bandwidth both within the above spectral range. A second transceiver transmits at the second bandwidth and receives at the first bandwidth.

Abstract: An excited state atomic line filter. The present invention solves the problem of lack of ground state resonant lines in at wavelengths substantially longer than those of visible light. Atomic line filters of the Faraday or Voigt crossed polarizer type are provided in which alkali metal atomic vapor in a vapor cell is excited with a pump beam to an intermediate excited state where a resonant absorption line, at a desired wavelength, is available. A magnetic field is applied to the cell producing a polarization rotation for polarized light at wavelengths near the resonant absorption lines. Thus all light is blocked by the cross polarizers except light near one of the spaced apart resonant lines. However, the polarization of light at certain wavelengths near the resonant is rotated in the cell and therefore passes through the output polarizer.

Abstract: An optical cross connect switch. In this switch any optical fiber in an input set of optical fibers, each carrying a communication beam, can be cross connected to any optical fiber in an output set of optical fibers. An alignment beam is added to and aligned co-axially with the communication beam carried by each fiber in the input set of optical fibers to define a communication-alignment beam for each fiber. Each communication-alignment beam is directed within a confined optical pathway to a specific exit aperture in an input array structure. The exit apertures for all of the communication-alignment beams are arranged in a pattern defining an input array so that each communication-alignment beam can be identified by the location of its exit aperture in the input array structure. Each communication-alignment beam is formed into a cross-connection beam by a micro-lens in a first lens micro-lens array.

Abstract: An imaging millimeter wave radar system. The system includes a millimeter wave transmitter transmitting a frequency scanned millimeter beam that is narrow in the scanned direction and wide in a direction perpendicular to the scanned direction. The system includes a receive antenna and a Rotman type lens for forming a one-dimensional image in the perpendicular direction of targets in the antennas field of view based on millimeter wave radiation reflected from the targets. A computer creates a two dimensional image based on the scanning direction of the transmit beam of the transmit antenna and the one dimensional image from the receive antenna. Distance to the target is determined based on difference in frequency of the transmit signal and the receive signal. Thus, a three dimensional view of the systems field of view is determined by the system. This view can be displayed on a monitor using color to represent target distance.

Abstract: A millimeter wave imaging system that includes at least one millimeter wave frequency scanning antenna for collecting frequency dependent beams of millimeter wave radiation from a narrow one-dimensional field of view. The collected radiation is amplified at the collected frequencies and the amplified signals are separated into frequency dependent bins with a tapped-delay beam-former. These bins are then sampled to produce a one-dimensional image of the antenna field of view. A two dimensional image of a target may be obtained by moving the target across the field of view of the scanning antenna. In a preferred embodiment the antenna is only 4.5 inches in length and constructed from WR-10 waveguide with inclined slots cut in one of the narrow walls at 79 mil spacings. This geometry creates a frequency-scanned antenna spanning a 20 degree vertical field of view over a 75.5-93.5 GHz operational band of the sensor, starting at approximately 1 degree below horizontal at 93.

Abstract: An apparatus and method for the alignment of a converging light beam with a fiber having a core and cladding, using light leaked from the cladding is provided. Light from an incoming light beam is leaked from the cladding and passes through a ferrule surrounding the cladding, to light sensors located adjacent the ferrule. When any sensor senses light, that sensor signals the converging light beam to move away from that sensor (and towards the core of the fiber) until no light shines on that sensor. Each sensor performs this same function until no light shines on any sensor, indicating a proper alignment of the light on the core of the optical fiber.

Abstract: A method and system for detecting a power level of a communication light beam is disclosed. In one embodiment, a fiber optic switch beam generation element generates a communication light beam that may be received at a beam splitter. The beam splitter may be configured to produce a reflected light beam that reflects a portion of the communication light beam, while permitting at least a portion of the communication light beam to propagate through the beam splitter. A reflected light beam detector may be used to detect the reflected light beam. The power level (e.g., light energy) of the communication light beam may then be calculated based on the light energy of the reflected light beam.