Abstract: A reception simplified, reduced cost spread spectrum transceiver device and method. The transmitting portion of the transceiver antipodally modulates a pseudorandom code and non-antipodally modulates binary bit data onto a carrier wave. The receiving portion of the transceiver performs a mathematical squaring function on the received signal combination of pseudorandom code and data. Squaring the pseudorandom code results in a cancellation of the code and the data remains in the absence of the pseudorandom code. The device and method of the invention eliminates the need for storing or generating a local reference for the spreading code or the need for any knowledge of key signal parameters at the receiver greatly simplifying receiver circuitry and allowing receiver operation at low energy density and low operational cost. Additionally, the device and method of the invention eliminates the synchronization constraint between the transmitted data and spreading code of conventional systems.

Abstract: Computer controlled fiber coating chemical vapor deposition system and method for generating substantially uniform coated fibers by maintaining chemical vapor deposition reactor temperature in real time. Reactor temperature is monitored by in situ temperature sensors. Reactor temperature is sensitive to oxygen levels and oxygen levels within the reactor are varied in response to temperature sensor data. Closed loop process control software maintains reactor temperature at a preselected value resulting in predictable fiber coatings of a preselected thickness, crystallinity and chemistry.

Abstract: A semiconductor material avalanche photodiode photodetector having ultraviolet response, solar radiation immunity and response speed in excess of that available from conventional ultraviolet photodetectors is described. The detector is an avalanche photodiode comprised of periodic table group III-Nitride semiconductor material, such as aluminum gallium nitride, serving as a photon to charge carrier transducer, and an avalanche charge carrier multiplication region comprised of different semiconductor materials such as silicon. The photodetector is capable of selective ultraviolet signal transducing while exposed to a mixture of ultraviolet and solar energy “noise” radiation. The included avalanche multiplication region is optically shielded from solar and other energy components to enable this selective capability. A multiplied ultraviolet photoresponsive electric signal is collected from output electrodes disposed adjacent the avalanche multiplication structure.

Abstract: A solid state laser device made from a nonlinear optic quaternary alloy of Silver, Gallium, Selenium and Tellurium semiconductor material or Silver, Gallium, Sulfur and Tellurium semiconductor material. The Tellurium component in each alloy provides quaternary alloying anion modification of an underlying ternary semiconductor crystal and achieves tuning of the birefringence and tuning of the wavelength passband of the semiconductor material. The tuned quaternary alloy enables beam walkoff-free noncritical phase match operation of the laser device including use of a phase match angle supporting optimum use of the material's nonlinear properties, maximized useful length of the material crystal, room temperature wavelength changing operation, significantly increased second order nonlinear susceptibility, a factor of ten reduction in the walk-off angle and photon energy conversion efficiencies several times those usually achieved.

Abstract: A method and device for generating a pseudorandom electrical signal for enabling spread spectrum communication scrambling by directing data entry into pseudorandom number generator integrated circuit chip controlling registers using a length selectable feedback logic data sequence and either computer programmable selector means or manual selector means to communicate the logic data sequence characters to buffers. The logic data sequence characters are clocked to a pseudorandom number generating register of an integrated circuit chip and the pseudorandom electrical signal is generated by selectively tapping a signal code therefrom. The method and device features a pseudorandom electrical signal length varying capability and is portable to various laboratory applications without a change in hardware configuration.

Abstract: A broadband radio receiver of the type usable in receiving and identifying the pulsed signals of radar transmitters in an electronic warfare environment. The receiver includes signal presence detecting apparatus in the form of a time domain signal detection apparatus usable in maintaining complex signal processing portions of the receiver, such as its fast Fourier transform generation circuit, in quiescent low energy dissipating status until needed to perform signal analysis. Such energy conservation enables use of the receiver in energy limited remote or space received environments. Energy conserving “clockless logic” or “null convention logic” is preferably used in embodying greater energy dissipating portions of the receiver.

Abstract: An aircraft missile vulnerability reduction system based on missile hit acceptance whereby a targeted aircraft's most critical components are protected by a preprogrammed, missile-attracting infrared decoy strategically positioned on a sacrificial portion of the aircraft's structure. The decoy is optimally located based on vulnerability analyses and includes multiple modes of operation that configure to instantaneous survivability needs. The system is capable of providing aircraft survivability against shoulder launched man-portable air defense systems missiles during low-level mission flight scenarios.

Abstract: A passive radio frequency signal-enabled aircraft altimeter employing signals of one or more global position system satellites as a source of terrain illumination. The altimeter determines altitude of the host aircraft with respect to specific terrain features beneath the aircraft rather than an altitude above a mean or nominal level of the earth's surface—as is already provided in a global position system signal. The altimeter employs two signal paths between the global position system satellite and the host aircraft, one direct signal path and one earth-reflected signal path, together with elementary geometric/trigonometric relationships, involving length difference in these paths and signal angle of arrival, in determining aircraft altitude. Equal angles of satellite signal incidence and reflection at the point of satellite signal reflection from the earth is an enabling principle in the altimeter.

Abstract: A passive system for locating a distant source of radio frequency energy, for example a pulsed radar transmitter, from a portable platform such as a moving aircraft. The disclosed system is non ambiguous in locating ability by way of using time difference of arrival and time difference of arrival-rate processing of signals received from the distant source. This is in contrast with phase-based locating wherein location ambiguities are inherent. The disclosed system is supported by an included recalibration subsystem enabling practical maintenance of time difference of arrival system algorithm accuracy notwithstanding physical component and signal delay changes attributable to thermal or other environment effects. Maintenance of delay measurements accurate into the tens of picosecond range by this recalibration arrangement are employed to obtain usefully precise energy source locations. Mathematical equation-based disclosures of signal delay algorithms and their recalibration are included.

Abstract: An air to air homing missile guidance algorithm based on a state-dependent Riccati equation solution of a spherical-based nonlinear intercept representation of the intercept kinematics problem. The achieved algorithm also provides characteristics asymptotically stabilizing the intercept kinematics achieved with the classic proportional navigation or PRONAV intercept algorithm but provides reduced hunting instability and other fuel-consuming and time consuming missile maneuvers. The disclosed algorithm is in the form of four state equations, two equations for an angular acceleration embodiment and two for a linear acceleration embodiment. Each such embodiment includes seven state variables each having a gain coefficient of complex fraction form; each embodiment is additionally refined for differing cross-channel couplings.

Abstract: A computer controlled, three-dimensional, iterative and reiterative, closed-loop system for automatically positioning the head of a manikin situated on a motorized stand relative to a stationary sound source in order to perform accurate near-field Head-Related Transfer Function (HRTF) measurements. The positioning is based on acoustic signals measured from microphones located at each ear of the manikin and is accomplished with three-axis precision for accurate near-field HRTF measuring.

Abstract: An enhancement mode periodic table group III-IV semiconductor field-effect transistor complementary pair device is disclosed. The disclosed complementary pair include single metallization for ohmic and Schottky barrier contacts, a permanent non photosensitive passivation layer (a layer which has also been used for masking purposes during fabrication of the device) and gate elements of small dimension and shaped cross section to provide desirable microwave spectrum electrical characteristics. The complementary pair of the invention is fabricated from undoped semiconductor materials disposed in a layered wafer structure and selectively doped by ion implantation to achieve both the p-channel and n-channel transistors. The semiconductor materials may include two, one or zero buffer layers in their layer structure. The disclosed complementary pair is of reduced fabrication cost, increased dimensional accuracy and state of the art electrical performance.

Abstract: A device is described which incorporates three components: a tracking error estimator, a detector, and a red light indicator to alert a pilot to the potential loss of tracking control. The tracking error estimator uses the difference between the target and the desired response of the tracking aircraft to estimate the divergence from a desired tracking path. This difference is acquired by such systems as, for example, the Global Positioning System (GPS) and radar. The tracking error and its derivatives are then converted into three different metrics. The metrics represent percentage points when the tracking error and its derivatives are in an unstable or stable portion of its phase plane. Depending upon whether these metrics and/or their combinations are above a particular threshold, the detector and indicator will alert the pilot or operator whether or not corrective action needs to be taken. The threshold is determined by a predetermined logic tree.

Abstract: A method for fabricating a periodic table group III-IV metal semiconductor metal field-effect enhancement mode complementary transistor pair device is described, a device typically made of gallium arsenide materials. The disclosed fabrication uses initially undoped semiconductor materials, single metallization for ohmic and Schottky barrier contacts, employs a non-alloyed ohmic contact semiconductor layer and includes an inorganic dielectric material layer providing non photosensitive masking at plural points in the fabrication sequence. The invention uses selective ion implantations, and a combined optical and electron beam lithographic process, the latter in small dimension gate areas. These attributes are combined to provide a field-effect transistor complementary pair of reduced fabrication cost, low electrical energy operating requirements increased dimensional accuracy and current state of the art electrical performance. Fabricated device characteristics are also disclosed.

Abstract: A broadband microwave coplanar antenna suitable for use in singular antenna or antenna array dispositions in a plurality of military and other present day uses. The disclosed antenna combines desirable characteristic of the patch and slot antenna forms into an arrangement having both patch resonances and slot resonances. These resonances may be individually accessed and either combined in frequency location or dispersed in frequency to accomplish a broadband combination antenna characteristic. Broadband electrical impedance characteristics are also provided in the dispersed resonance arrangement. The antenna includes a coplanar ground plane member disposed surrounding the active patch/slot element with both physical dimensions of the active patch/slot element and spacings from the ground plane element determining the resonances.

Abstract: Acoustic point source transducer apparatus including a high-output acoustic sound source propagating sound through a long, flexible tubing having an open end with a small diameter. Sound radiates from the small diameter open end effectively acting as an acoustic point source. A flexible sleeve encasing the terminal end of the tubing permits convenient wand-like placement of the acoustic point source by a human operator and an electromagnetic position sensor at the small diameter open end determines point source position. The invention provides a convenient, nondirectional approximated acoustic point source for improved acoustic measuring, especially desirable for near-field Head-Related Transfer Function measuring.

Abstract: An electrical winding fault detection system wherein turn-to-turn and other winding faults in a polyphase alternating current machine are identified through processing of measured machine winding current flow changes, i.e., through identification of changes in electrical balance conditions in the machine. This disclosed processing includes scaling or normalization of measured operating currents using current measurements made while the machine is known to be in fault-free normal operating condition and altering the normalization by a relationship between average current flow in the fault-free condition and average current flow in the monitored changing load condition. Machine operation from a balanced energization source is preferred for successful use of the system; it is therefore especially suited to multiple phased machines operated from electronically derived alternating current energy. The invention is disclosed primarily in terms of a motor-operated machine; however, application to generator (i.e.

Abstract: A method for determining distance from a target to an observation station using a Global Positioning System satellite as a radiation source and first and second observation station located receivers. The first receiver receives reflected position determinative satellite radio frequency signals and the second receiver receives direct position determinative satellite radio frequency signals. The time difference between satellite radio frequency signals arriving at the first and second receivers is calculated and combined with difference distance data and angular, azimuth and elevational position data and the distance from the target to observation point is determined.

Abstract: A method for making a magnetoresistive sensing device including depositing an ultrathin active film responsive to changes in magnetic field energy onto a compliant layer of periodic table group III-V semiconductor material on a semiconductor substrate wafer, the compliant layer being capable of retaining strain energy resulting from the layering semiconductor materials with different lattice constants. This method produces a battery operable ultrathin device highly sensitive to changes in magnetic field flux.

Abstract: An improved center high-mounted stoplight apparatus for a motor vehicle or other transportation apparatus. The apparatus includes a pulsating or flashing mode of operation used to indicate rapid deceleration of the vehicle. This pulsating or flashing mode is in addition to the regular continuous mode of operation used for normal braking and deceleration and is arranged to be of a maximal human visibility and attention-capturing operating cycle. A plurality of different signaling arrangements to a following vehicle including an incandescent lamp, a gas tube lamp, light-emitting diode devices and non light-based signaling are also contemplated. Additionally included is a maximal distance spanning attention-capturing operating mode entered into in response to, for example, a collision-related deceleration event and maintained over a prolonged operating time or until manually disabled.