Abstract: It has been found that target optics produce non-specular, augmented optical returns when interrogated by a laser pulse. This non-specular radiation is detected by an active laser search system employing a direct-reading, thresholded focal plane detector that is able to detect non-cooperating targets with optics that employ a detector or optical element at the focal plane of their receiving optics. The pulses returned from such target optics have a width commensurate with the original transmitted pulse width, whereas passive background noise and the spread out active returns from the ground exhibit temporally long returns. By setting the sensor threshold sufficiently high, the system discriminates against noise and clutter while at the same time reducing the number of sweeps required to detect a target within the search area.

Abstract: The invention provides a method and apparatus for correcting for gain changes in detectors in a guided vehicle. In one version of the invention, an on board light source is used to generate a reference set of detector gains, which are stored in computer memory. The on board light source is then pulsed at subsequent times and the signals generated by the detectors are compared to the reference set of detector gains to determine whether any gains have changed.

Abstract: A system for the transmission of data by seismic wave, the system having at least one transmitting unit, that at least one transmitting unit comprising a first processing unit encoding a first signal, the first processing unit being coupled to a digital to analog converter, an amplifier amplifying the first signal, and a seismic pressure wave inducer transmitting the first signal to a geological feature; and at least one receiving unit, the receiving unit comprising at least one receiver coupled to the geological feature for receiving the first signal, and an analog to digital converter whereby the first signal is transferred from the geophone and is conveyed to a second processing unit, the second processing unit being configured to identify and decode the first signal.

Abstract: An antenna formed with a number of notch antennas forming an sectional inner ring and a sectional outer ring. Each of the notch antennas having a pair of leaves with a throat end proximate the inner ring and a leaf tip end proximate the outer ring, wherein the leaves are separated by a notch area. There is a lagoon interiorly disposed about the inner ring. At least one feed is coupled to at least one throat end. A lower horizontal loop couples each leaf tip and forms the outer ring. In addition, a plurality of slots separates each of the notch antennas.

Abstract: A wideband, e.g., 550 nm to 940 nm, apochromatic lens system for use with an external aperture stop, includes first, second, and third optical groups having, in order, positive, negative, and positive powers. The first group includes four optical elements having, in order, negative, positive, negative, and positive powers. The second group includes one element of negative power; and the third group includes two elements each having positive power. In another embodiment for use with an internal stop, the system includes first, second, and third optical groups having, in order, positive, positive, and negative powers. The first group includes four optical elements having, in order, positive, negative, positive, and negative powers. The second group includes one element of positive power, and the third group includes one element of negative power. In either embodiment, all of the optical elements are formed from not more than three different types of glass material.

Abstract: A sensor is provided for analyzing an object at a focal point of a lens. The sensor includes a focused radiant energy source directed at the lens. The focused radiant energy source transmits a first beam of energy to the lens, vaporizing a portion of the object at the focal point of the lens. A second beam of energy is emitted from the vaporization of the object. A spectrometer is positioned to receive the second beam of energy emitted from the object. The second beam of energy is at least partially transmitted anti-parallel to the first beam of energy.

Abstract: A Fermi threshold voltage FET has Germanium implanted to form a shallow abrupt transition between the semiconductor substrate dopant type, or well dopant type, and a counter doping layer of opposite type closely adjacent the surface of the semiconductor substrate. Germanium is a charge neutral impurity in silicon that significantly reduces the diffusion motion of other impurity dopants, such as As, P, In, and B in the regions of silicon where Ge resides in significant quantities (i.e. greater than 1E19 cm sup3).

Abstract: A method for connecting circuit elements within an integrated circuit for reducing single-event upsets is disclosed. The integrated circuit includes a first and second circuit elements that are substantially identical to each other. In order to reduce the single-event upsets to the first and second circuit elements, each of the first and second circuit elements is divided into a first sub-element and a second sub-element. The first sub-element of the first circuit element is connected to the second sub-element of the second circuit element. The second sub-element of the first circuit element is connected to the first sub-element of the second circuit element. As a result, the nodal spacings between the sub-elements within the first and second circuit elements are effectively increased without demanding additional real estate.

Abstract: Apparatus and methods for providing efficient space-time structures for preambles, pilots and data for multi-input, multi-output (MIMO) communications systems are provided. One such embodiment includes providing a computer program that includes logic configured to provide an initial structure. The computer program further includes logic configured to verify that the rows of the initial structure are linearly independent and logic configured to apply an orthonormalization procedure to the initial structure to obtain a space-time structure. Methods are also provided for providing efficient space-time structures for preambles, pilots and data for MIMO communications systems.

Abstract: A Moving Transmitter Correlation Interferometer Geo-Location (MT-CIGL) system is disclosed that permits locating both moving and stationary transmitters from moving DF equipment. A conjugate gradient based search routine is utilized which solves for the location of moving and stationary transmitters at the start of each measurement sequence and then solves for the velocity and direction of motion of the moving transmitter. This information is used to track the moving transmitter. Received signals are sampled, digitized and stored in covariance matrices. They are then summed and normalized using an equation that has velocity terms that are set to zero to minimize extraneous correlation peaks, and a maximum correlation peak is developed. A conjugate gradient search routine is used to find the correlation peak of the summed data. The value of the peak is then analyzed to see if it is above or below a predetermined value.

Abstract: A communication system is provided herein for transmitting frames across a channel. The frames may be transmitted in single-input, single-output (SISO) and/or multi-input, multi-output (MIMO) communication systems. One such frame includes at least one training symbol, each having a cyclic prefix and a training block. The time length NI of the training block is equal to an integer fraction I of the time length of a data block, i.e., NI=N/I. Furthermore, the time length G of the cyclic prefix is an integer fraction of the time length NI. For example, G may be equal to NI/4 or 25% of NI. The training symbols provide coarse and fine time synchronization, coarse and fine frequency synchronization, channel estimation, and noise variance estimation.

Abstract: Conductor segments are positioned within a two conductor transmission line in order to generate microwave pulses. The conductor segments are switchably coupled to one or the other of the transmission lines in parallel. Microwave pulses may be induced in the transmission line by closing the switches in a controlled manner to discharge successive segments into the transmission lines. The induced waves travel uninterrupted along the transmission lines in a desired direction.

Abstract: The present invention is a digital communication method that increases the overall throughput of a Multiuser Detection (MUD)-based co-channel multiple access (MA) system in terms of the total number of bits transmitted through the shared medium by all the users of the MA system if signals are allowed to interfere. The total number of users can be increased if more dimensions are used for assigning the transmitted signals and the same dimensions are measured at the receiver. Specifically, the present invention does not require any coordination among transmitters but simply requires a transmitter to send its signal with either a randomly chosen polarization ellipse, or an assigned or randomly chosen amplitude level.

Abstract: An apparatus for inspecting semiconductor module packages which includes a cylindrical base section, a truncated spherical section superimposed on the cylindrical base capable of being rotated and tilted on the cylindrical base section, and a tray section superimposed on the truncated section.

Abstract: The weight of liquid in a tank subject to tilting is determined by measuring differences in air pressure in the ullage (the empty volume of the tank above the level of the liquid) and the air pressure produced by the weight of the liquid at the bottom of the tank. The pressures at the bottom of the tank are measured in a plurality of locations, and the differential pressures are combined to compensate for changes in the depth of the liquid when the tank is not level (e.g., when the tank is in an aircraft flying at an attitude other than straight and level). The electronics to measure the pressure and to process the pressure measurements are located remotely form the tanks, thus eliminating the possibility of ignition caused by the electronics when the liquid is fuel or other flammable liquid.

Abstract: A continuous tunable laser system includes at least one DBR laser. The DBR laser includes a Phase section, a Braggs section, and a gain medium. The DBR laser is capable of generating a continuous-wave laser signal. A Phase current input is electrically connected to the Phase section. A Bragg current input is electrically connected to the Bragg section and synchronized with the Phase current input. A gain control input is electrically connected to the gain medium.

Abstract: A calibration system is provided for calibrating frequency domain reflectometers in the field by using both the scattering parameters of the multi-port junction determined at the factory and changing the offset and gain terms used in generating a complex reflection coefficient by using internal calibrated loads so that heavy, cumbersome external calibrated transmission lines are not required. In one embodiment the internal calibrated loads include RLC circuits and in another embodiment the internal calibrated loads include attenuators. Further, retesting or recalibration does not necessitate reconnecting the cable under test, which may remain connected to the reflectometer's test port throughout the procedure.

Abstract: A power combiner/divider is disclosed that employs triaxial transmission line structures operatively coupled to provide a desired number of input/output ports. A balun is operatively coupled to the triaxial transmission line structures, and is adapted to couple out unbalanced currents flowing therebetween.

Abstract: Windowed multiuser detection techniques are disclosed. A window of data is established, and certain central bits within the window are selected as reliable, while other side bits are ignored. The selected bits are demodulated. The windowed multiuser detector moves along to the next window in such a manner that the next group of central bit decisions lay contiguous with the previous set, and eventually every bit to be demodulated has at some point been a central bit decision. Most any type of MUD algorithm (e.g., MMSE algorithm MUD or M-algorithm MUD) can be used to compute estimates in the windowed data. Unreliable windowed data are distinguished from reliable data (e.g., weighting or other de-emphasis scheme).

Abstract: The present invention relates to an apparatus and process for producing a thin organic film on a substrate using an ultrasonic nozzle to produce a cloud of micro-droplets in a vacuum chamber. The micro-droplets move turbulently within the vacuum chamber, isotropically impacting and adhering to the surface of the substrate. The resulting product has a smooth, continuous, conformal, and uniform organic thin film, when the critical process parameters of micro-droplet size, shot size, vacuum chamber pressure, and timing are well-controlled, and defects such as “orange peel” effect and webbing are avoided. The apparatus includes an improved ultrasonic nozzle assembly that comprises vacuum sealing and a separate, independent passageway for introducing a directed purging gas.