Abstract: An obstacle avoidance system, apparatus, and method is described suitable for use on autonomously guided or man-in-the-loop guided vehicles such as aircraft, missiles, cars, and other types of vehicles. The system provides guidance instructions in the situation where the vehicle encounters an obstacle either directly or indirectly in its path while traveling to a desired destination or where vehicles are traveling in formation. The system can be applied not only to obstacle avoidance but also to trajectory shaping by defining obstacles, operational boundaries and/or threats which influence the trajectory of the vehicle.

Abstract: An electrically-conductive, thermally-insulating structure includes a thermally-insulating layer having a thermal conductivity of no more than about 3.5×10−3 W/hr·cm·°K and an electrically-conductive layer, applied to the thermally-insulating layer, which has an electrical resistivity of no more than about five ohms at 700° C. The thermally-insulating layer can include a plurality of microballoons to decrease the density of the thermally-insulating layer.

Abstract: A two-color photodetector for detecting two different bands of infrared radiation is described. The photodetector includes either a diffractive resonant optical cavity that resonates at the two colors of interest, or a diffractive resonant optical cavity that resonates at the first color and a vertical resonant optical cavity that resonates at the second color. By placing materials that absorb only one of the two colors at the appropriate locations within the resonate structure, the resultant signals include little cross-talk due to the opposite color. The two-color photodetector finds use in applications covering a wide portion of the infrared spectrum.

Abstract: An antenna array structure is disclosed for use in receiving, transmitting, or transceiving electromagnetic radiation. The antenna array structure includes a first planar substrate with one or more grooves formed therein with at least one secondary planar substrate having an antenna formed thereon placed in one of the grooves in the first substrate. The use of this three-dimensional structure takes advantage of the inherent directionality due to the guidance of electromagnetic radiation by the secondary planar substrate. This antenna array structure provides the advantages of reduced cross talk between adjacent antennae and can readily be produced using standard silicon fabrication techniques.

Abstract: An infrared detector array includes a plurality of detector pixel structures, each having a plurality of coplanar sections responsive to different bands of infrared radiations. Each section of a pixel structure comprises a plurality of elongate quantum well infrared radiation absorbing photoconductor (QWIP) elements. The group of QWIP elements are spaced such that they comprise a diffraction grating for the received infrared radiation. Top and bottom longitudinal contacts are provided on opposite surfaces of the QWIP elongate elements to provide current flow transverse to the axis of the element to provide the required bias voltage. An infrared radiation reflector is provided to form an optical cavity for receiving infrared radiation. A plurality of detector pixel structures are combined to form a focal plane array. Each pixel structure section produces a signal that is transmitted through a conductive bump to a terminal of a read out integrated circuit.

Abstract: In a first aspect, the invention uses the thrust and axial aerodynamic forces of and on the missile system as the primary mechanism for altering the missile system's flight path as opposed to the missile system's aerodynamic normal force. In accordance with this first aspect, a first embodiment is a method for changing the direction of travel of a vehicle moving through a fluid medium to a desired direction of travel measured in the vehicle's inertial frame of reference, the vehicle comprising a body including a nose, a moment generating control device, and an axial propulsive device. The method comprises actuating the moment generating control device to align the nose substantially with the desired direction of travel, and applying the axial propulsive device as the primary mechanism to redirect the vehicle's velocity to the desired direction of travel. In a second aspect, the invention provides a missile control system implementing the first aspect of the invention.

Abstract: A switched frequency multiplier receives pulses of pump energy as an input signal. The input signal is transferred to within a housing having a first cavity tuned to the frequency of the pump signal and a second cavity which is tuned to a harmonic of the input signal and is enclosed within the first cavity. An outlet port couples the second tuned cavity to a waveguide which includes a Q-switch that can be turned on and off. The interior of the housing has a planar grid of layers which includes a layer of nonlinear material and a frequency selective layer. The frequency selective layer is transparent to the input signal but reflective to the harmonic output signal thereby trapping energy in the second cavity. The multiplier operates by receiving a pump pulse and storing the energy while the Q-switch is closed. When the Q-switch is opened near the end of the pump pulse, the stored energy is suddenly released to produce a relatively high energy harmonic pulse having a shorter duration than the pump pulse.

Abstract: A system is provided for generating multiple frequencies in a specified frequency band, with a specified step size between frequencies, in which the spectral purity of the frequencies is assured. The switching speed between frequencies is very fast, limited only by the speed of the switches used. In one embodiment, only five tones are generated as the base for the rest of the synthesis, in which the relationship of the five tones is f0+/−⅛f0 and +/−{fraction (1/16)}f0. The subject system in one embodiment, utilizes a channel synthesizer and a doppler offset synthesizer which may be utilized in air defense systems for generating the transmit channels to be able to permit a missile seeker to transmit a signal at the appropriate frequency. In one embodiment, spectral purity is achieved by providing a number of stages of up converting, expanding, and dividing down of an input signal.

Abstract: A microwave parametric amplifier uses a circulator to receive an input signal which is provided through a transfer port to an input signal resonant cavity. A pump signal, which is preferably a harmonic of the input signal, is received into a pump signal cavity which is defined by a barrier that is reflective to the pump signal and transmissive to the input signal. A non-linear medium is positioned within the pump signal cavity to produce carriers due to the energy of the pump signal. The input signal interacts with the carriers to produce an amplified input signal which is conveyed from the input signal cavity through the circulator to an output port of the circulator.

Abstract: An apparatus for moving a load has a boom with a lower end and an upper end and a base having a front end and a rear end. The front end of the base is pivotably connected to the lower end of the boom along a pivot axis, wherein a lower surface of the base rests on a support surface while a load is being moved. A first restricting mechanism restricts relative movement between the boom and the base about the pivot axis in a first direction and a second restricting mechanism restricts the relative movement between the boom and the base about the pivot axis in a second direction. A pulley mechanism is disposed proximal to the upper end of the boom. A rope having a load end is provided, wherein the load is attachable to the load end of the rope. The rope is threaded through the pulley mechanism.

Abstract: A Q-switched parametric cavity microwave amplifier has input and output ports for receiving an input signal and producing a switched amplified output signal. A pump signal, preferably at a harmonic of the input signal, is received through a pump signal port and provided to a pump signal cavity within a housing. The pump signal interacts with a non-linear medium to produce carriers. A frequency selective layer reflects the pump signal but permits the input signal to pass therethrough. The input signal interacts with the carriers produced in the non-linear medium to enhance the signal present within the resonant cavity for the input signal. This transfers energy from the pump signal to the lower frequency input signal. A Q-switch is positioned in series with the output waveguide to cause energy to be stored within the input signal cavity. When the Q-switch is opened, a pulse is produced representing an amplified version of the input signal.

Abstract: An autopilot controller, for controlling a vehicle traveling in a fluid medium, designed for controlling the vehicle in any one of pre stall, stall and post stall regions. The autopilot controller provides an approach for one-to-one mapping between a target command which is received and control surface deflections for effecting the command based on vehicle normal force and vehicle moment response characteristics. In one embodiment, the autopilot controller determines linear functions representative of the vehicle dynamic response for the current operating conditions in order to determine a direction of change of fin deflection for effecting the command. In another embodiment, the autopilot controller controls transverse vehicle accelerations by controlling a body pitch moment generated by a control surface.

Abstract: An autopilot controller, for controlling a vehicle traveling in a fluid medium, designed for controlling the vehicle in any one of pre stall, stall and post stall regions. The autopilot controller provides an approach for one-to-one mapping between a target force or moment command which is received and control surface deflections for effecting the command. In one embodiment, the autopilot controller determines linear functions representative of the vehicle dynamic response for the current operating conditions in order to determine a direction of change of fin deflection for effeeting the command.

Abstract: A variable bandgap infrared absorbing material, Hg1-x Cdx Te, is manufactured by use of the process termed MOCVD-IMP (Metalorganic Chemical Vapor Deposition-Interdiffused Multilayer Process). A substantial reduction in the dislocation defect density can be achieved through this method by use of CdZnTe layers which have a zinc mole fraction selected to produce a lattice constant which is substantially similar to the lattice constant of HgTe. After the multilayer pairs of HgTe and Cd0.944Zn0.056Te are produced by epitaxial growth, the structure is annealed to interdiffuse the alternating layers to produce a homogeneous alloy of mercury cadmium zinc telluride. The mole fraction x in Hg1-x(Cd0.944Zn0.056)xTe can be varied to produce a structure responsive to multiple wavelength bands of infrared radiation, but without changing the lattice constant. The alloy composition is varied by changing the relative thicknesses of HgTe and Cd0.944Zn0.056Te.

Abstract: An infrared radiation detector device has an array of detectors each of which comprises a pattern of parallel detector elements. Each detector produces a pixel signal for an image. The elements of the detector are photoconductive or photovoltaic bandgap materials, and the elements are spaced apart at a dimension which is equal to or less than the wavelength of the radiation to be received. Additional layered structures above and/or below the detector elements provide impedance matching between free space radiation and the radiation impedance of the detector elements to increase the capture of radiation.

Abstract: A system is provided for generating multiple frequencies in a specified frequency band, with a specified step size between frequencies, in which the spectral purity of the frequencies is assured. The switching speed between frequencies is very fast, limited only by the speed of the switches used. In one embodiment, only five tones are generated as the base for the rest of the synthesis, in which the relationship of the five tones is f0+/−⅛f0 and +/−{fraction (1/16)}f0. The subject system may be utilized in air defense systems for generating the transmit channels to be able to permit a missile seeker to transmit a signal at the appropriate frequency. In one embodiment, spectral purity is achieved by providing a number of stages of up converting, expanding, and dividing down of an input signal.

Abstract: A hyperspectral radiation detector system collects infrared radiation concurrently from a plurality of adjacent infrared spectral bands. A collector system includes an optical train for receiving the incoming radiation, a disperser for separating the received infrared radiation into multiple adjacent bands of interest and a focal plane array for detecting the individual infrared bands and producing corresponding output signals. The focal plane array is an enhanced quantum well infrared photodetector having multiple physical dimensions of each detector varied in a predetermined manner to alter the frequency of responsivity of the detector to form the multi-band pixels of the received image. The output signals from the array can be processed as required to review selected bands of interest or to determine if certain types of targets are present within the received radiation.

Abstract: A metal structural component (10) is formed by placing metal tubes (16) between two metal sheets (12) and plastically deforming the tubes (16) by injecting pressured gas therein. The injected gas expands the tubes by superplastic deformation until diffusion bonding occurs between the metal sheets (12) and expanded tubes (16) to form the desired support structure between the metal sheets (12).

Abstract: A process for producing a green composite structure by isostatic compression and filtration. A suspension of colloidal size matrix powders is established in a carrier liquid. The suspension is incorporated into a die chamber having a filter opening containing a filter which is permeable to filtrate from the suspension under applied pressure but substantially impermeable to the matrix powders. An elevated pressure is isostatically imposed on the colloidal suspension within the die chamber. The pressure is maintained for a period of time to expel at least 20% of the liquid originally in the colloidal suspension through the filter opening. A specific die chamber comprises a rigid cage structure and an expandable bladder within the cage structure into which the colloidal suspension is introduced. The cage structure is disposed within a pressure vessel which can be initially evacuated to cause the bladder to conform to the cage structure and then pressurized with fluid for the isostatic compression procedure.

Abstract: A comparative dual-control strategy actuates forward and aft control devices simultaneously to significantly improve a missile's maneuverability/dynamic capability. A substantial, and measurable, operational effect of the inventive control strategy is a dramatic improvement in a missile's divert capability. To effect a maneuver in accordance with the inventive strategy, a missile's aft fins are initially deflected to generate a force OPPOSITE that conventionally used (pushing the missile's tail in the direction of the commanded maneuver) which simultaneously actuating forward thrusters to also push the missile's nose in the direction of the commanded maneuver but at a faster rate than the tail section. This causes the missile body to simultaneously rotate and translate in the direction of the commanded maneuver.