Abstract: A fixed feed dual reflector scanning antenna system 10 having a low moment of inertia is disclosed herein. The inventive dual reflector antenna system 10 includes an antenna feed structure 16 for emitting electromagnetic radiation. The antenna system 10 further includes a subreflector 12 for redirecting the emitted radiation. The subreflector 12 is intersected by a subreflector longitudinal axis L.sub.s at a rotation point proximate a vertex 20 of the subreflector 12. A main antenna reflector 14 circumscribing a main longitudinal axis L.sub.m projects radiation redirected by the subreflector 12 as an antenna beam. A mechanical arrangement 22 rotates the subreflector 12 about the rotation point so as to vary the angular orientation between the subreflector longitudinal axis L.sub.s and the main longitudinal axis L.sub.m. In this manner the antenna beam is scanned relative to the main longitudinal axis L.sub.m.

Abstract: Test circuitry implemented in an integrated circuit having a plurality of outputs for testing the current at the outputs of output drivers of the integrated circuit without physical removal of the integrated circuit from an assembly in which it is incorporated. The test circuit includes a first test bus, a second test bus, and comparator circuitry responsive to the signals on the first and second test busses. Associated with each of the output drivers are (a) a current sensing resistor for sensing the current flow at the output of the buffer, (b) a first transmission gate connected between one side of the sensing resistor and the first test bus, and (c) a second transmission gate connected between the other side of the sensing resistor and the second test bus. The first and second transmission gates associated with an output buffer are controlled in parallel via a scan register.

Abstract: A passivated dichromated gelatin film in which the film includes a glassy oxide network to provide passivation and structural strengthening. The glassy oxide network is formed simultaneously with the gelatin formation via a sol-gel process.

Abstract: An n-way waveguide power divider wherein microwave power entering a first waveguide section is directionally coupled simultaneously into a plurality of parallel waveguide sections that share a longitudinal portion of their broad walls with a different longitudinal portion of the broad walls of the first waveguide section. The power is coupled through an individual pair of elongated axially-aligned coupling members in each of the shared broad wall longitudinal portions. The coupling members may have a variety of shapes including square, rectangular, circular, cross, or dog bone shapes.

Abstract: A reflection hologram structure including a transparent substrate, and a pattern of shielded hologram containing regions and transparent regions disposed on the transparent substrate, the pattern being unresolvable to the viewer. The shielded hologram containing areas comprise hologram subregions and shielding subregions overlying the hologram subregions. The shielding subregions comprise for example, opaque regions or partially illumination transmissive regions.

Abstract: A link sorted memory and method of storing and sorting data that provides for rapid sorting and retrieval of data stored in an unsorted fashion. The link sorted memory comprises a data memory for storing unsorted data, and a linking memory that functions as a pointer table to related memory addresses in the data memory. A sorting coprocessor is provided that stores the data unsorted in the data memory, scans the data words for a sort attribute, and uses the sort attribute to create the pointer table that links the unsorted stored data words. Sorting and retrieval of the unsorted data in the data memory is achieved by incrementing a counter, for example, that steps through the addresses stored in the linking memory to sequentially retrieve all data words having the sort parameter.

Abstract: A maximum likelihood estimator and range-only-initialization target detection method employed to detect and resolve targets in a multislope linear frequency modulated waveform radar. The method resolves a large number of target returns without a large amount of signal processing and without creating a significant number of false alarms, or ghosts. The method simultaneously estimates range and doppler for each target. The method rejects undesired long-range targets that fold into target regions, and processes target regions of interest around a nearest target to reduce signal processing throughput requirements. Using a K out of N detection rule, the method detects targets that compete with mainlobe rain clutter, mainlobe ground clutter, and receiver leakage. The method simultaneously estimates target parameters and optimally resolves any number of targets.

Abstract: An asymmetrical notch radiating element comprising a metal or metal-clad dielectric substrate into which a tapered slot or notch is disposed. The direction of the axis of the tapered slot lies along any preselected axis and is not constrained to be collinear with the normal to the aperture of the element. An asymmetrical antenna array comprises a plurality of asymmetrical notch radiating elements as described above. Each of the plurality of radiating elements is disposed such that the apertures of each of the elements are substantially coplanar and are at an angle relative to the notch axis. The present antenna uses asymmetric slot lines to control the antenna's electrical performance. The precise slot dimensions are chosen to optimize radiation and reduce scattering. The asymmetric flared notch allows optimization of the transmit gain in a direction that is not necessarily normal to the array surface.

Abstract: A structure integrity monitoring apparatus and method for use with certain structures such as air-frame structures. A meandering transmission line (22) or serpentine coaxial cable is adhered to a dielectric substrate (20). The dielectric substrate may be a composite panel of the air-frame structure. A microwave signal is introduced at one end of the transmission line (22) or coaxial cable and absorbed at the other end by an appropriate signal absorbing device. For use of the meandering transmission line (22), generally two conductors (22, 24) are affixed on opposite sides of the dielectric substrate (20). In this manner, an electric field created by the two conductors (22, 24) by the microwave signals propagating through them is confined within the dielectric substrate (20). As the signals travel down the transmission conductors (22, 24), they will be reflected at crossover points along the way creating a signature reflection wave.

Abstract: A strain, crack and acoustic emission conformal structural health monitoring circuit with integral preprocessor and provisions for connectorization to a central processing system includes a strain gauge (11) having crack sensing traces (21), (23), and (25) sandwiched between a bottom layer (13) and a top layer (39). Strain gauge (11) is attached to an aircraft structural surface (51) to be monitored. Successive alternating layers of interconnecting sheet layers (61) and dielectric layers (63) joined by successive layers of non-structural adhesive (65) are added sufficient to effectively attenuate any stress forces, and forces directly from the strain and cracks, from traveling upward from the aircraft structural surface (51).

Abstract: A heel grounding device (10) is disclosed which is used in connection with electrically grounded conductive flooring which in one embodiment is secured to the shoe (12) of a human operator. A strap (24) is secured about the leg (11) of the operator with conductive material (29) touching the operator. Grounding lead (25) attaches by a fastener (27) from conductive material (29) to partially conductive material (20) which is secured to the heel (15) of the shoe (12) of the operator. A strap (23) is used to secure the device onto the shoe (12) of the operator. Metal rivets (31, 32, 33) are secured in and protrude from partially conductive erlement so as to maintain electrical contact with the conductive grounded flooring to overcome soil build up on partially conductive material (20) and thereby maintain electrical grounding of the operator.

Abstract: A power rectifying circuit (10) for converting an AC power signal to DC which includes a plurality of rectifiers (20) that receive power from a single AC power source (12). The AC power signal is power split amongst the plurality of rectifiers (20). Each power split signal is phase shifted by an incremental amount of phase shift and provided to on of the rectifiers (20). The rectified DC output of each rectifier is summed together and provided to a load (22) as DC power.

Abstract: A phase difference autofocus method that only requires one FFT for estimating a phase error in the entire synthetic array radar data. The phase difference autofocus method of the present invention automatically and efficiently estimates phase errors from radar signals, allowing a well focused SAR image to be produced. The present method comprises the following steps. First, each range bin is divided into two subarrays. Next, the two subarrays are complex-conjugate multiplied together to produce a cross spectrum of the two submaps produced by the subarrays. Then, the phases of each cross spectrum are aligned with an accumulated sum of the cross spectrums from previous processed range bins. The phase aligned cross spectrum is then added to the accumulated cross spectrum sum. All range bins are processed to get a final cross spectrum sum. Next, a single FFT is performed on the final cross spectrum sum to produce the cross correlation function. Then, the cross correlation function is magnitude-detected.

Abstract: Circuitry and techniques are for transferring data between the automatic test equipment (ATE) and an integrated circuit under test pursuant to a slow clock that can have an arbitrarily long period, and for operating storage elements in the integrated circuit pursuant to a fast clock having a short period that corresponds to the clock rate at which combinatorial networks in the integrated circuit are to be tested. In one embodiment, input latches at inputs of the integrated circuit receive test data from the ATE, and output latches at the outputs provide test result data for the ATE. Pursuant the alternating single cycles of the slow clock and the fast clock, the delays through combinatorial networks between of a data propagation path between an input latch and an output latch are tested pursuant to the fast clock. In another embodiment, test data is serially scanned into scan registers pursuant to a series of slow clock cycles.

Abstract: Die punch apparatus including an electromagnetic die head core having a plurality of punch die retaining apertures, a plurality of magnetically attractable die punch assemblies respectively retained in the plurality of die retaining apertures, and a receiver plate core having punch receiver assemblies for receiving the punch pins of the punch die assemblies.

Abstract: Fast fourier transforms are performed in digital signal processing using number theoretic transforms. Incoming pulse descriptor words are mapped into a matrix. The first convolution does forward and inverse number transforms on the rows. The second convolution does forward and inverse number transforms on the columns.

Abstract: An attachment structure is described that provides means for holding and for applying tensile force to an optical fiber clamped therein. Attachment to an optical fiber is accomplished by stripping the buffer layer(s) from a portion of the fiber and casting a thermosetting polymer encapsulating and compressing member thereon at elevated temperature so that, at lower than the polymer curing temperature, the cast polymer encapsulating member is in compression on the bared fiber and on a short portion of its adjacent buffer layer(s). A tension wire which provides a means for applying external force to the optical fiber has one end inserted axially in the mold for incorporation into the cast encapsulating member. The wire is also placed under compression at temperatures below that of the curing temperature of the polymer. To maintain compression over temperature elevated temperatures, a restrictive cylindrical coil spring is directly engaged around the encapsulating member.

Abstract: A portion of the ambient air, including the selected vapor such as the ether vapor fraction, is first cryogenically liquefied for concentration in a collecting vessel (12). Thereafter, the concentrated liquefied fraction is boiled off and passed through gas chromatography column (34) to separate the fractions in the vapor stream. The selected vapor fraction is eluted at the temperature, and its concentration is detected by thermal conductivity detector (42) so that the concentration of the selected vapor in the environment is signaled.

Abstract: A holographic full-color, data retrieval and projection system includes a holographic information storage plate that includes a plurality of reflective holograms, each designed to diffract light over a certain spectral bandwidth, and a holographic screen character plate, which includes a plurality of screen hologram character shapes that reflect diffracted light in a uniform, well-defined cone of diffuse light directed toward the viewer, producing images having high screen gain and high brightness, yet with lower power consumption than heretofore obtained.

Abstract: The method and apparatus for storing the data base of gridded type data on a plurality of rotary type data memory devices such that data update to a utilization system, e.g., a computer generated imagery (CGI) processor may be more effectively implemented. For the generalized case of N rotary data memory devices and for a data base of gridded type data which may be represented by rows and columns of data elements, data elements of each row are "mapped" to the memory devices in accordance with a repetitive and cyclical pattern. For example, for each row of the grid, the data for each data element of N successive elements is stored on a different one of the N rotary data memory devices and for successive groups of N elements the data is similarly stored in accordance with a repetitive, cyclical pattern wherein each cycle of the pattern includes N successive elements, the data for each of which is stored on a different one of said rotary data memory devices.