Abstract: A frequency selective reflector is provided for use in an electromagnetic antenna system, wherein the frequency selective reflector reflects electromagnetic waves having two or more frequencies. The reflector includes an inner portion which has a reflective surface which will reflect at least first and second frequencies. The reflector also includes an outer portion which will reflect electromagnetic waves having the first frequency in substantially the same direction as electromagnetic waves of the first frequency reflected from the inner portion. On the other hand, the outer portion is constructed to prevent the constructive reflection of electromagnetic waves of the second frequency in the same direction as electromagnetic waves of the second frequency reflected from the inner portion.

Abstract: A method for aligning the optical surfaces of the high extraction annular ring resonator which includes a scraper mirror with a decentered aperture. A probe beam, from an external laser, is directed into the resonator cavity through the decentered aperture in the scraper mirror. The symmetrical properties of the probe beam near and far field intensity distribution patterns are used to align the optical surfaces within the cylindrical ring resonator.

Abstract: There is provided a countermeasure defense system against hostile missiles by employing non-explosive intercepting (“NEI”) elements 14 deployed by the spin stabilized rocket 10. The NEI are carried in a payload section 17 and contained by a sleeve assembly 16 which is removed by a drive mechanism 20 or a pyrotechnic device 152 after a countdown time delay programmed into the trigger release assembly 46 as controlled by the control unit 150. The drive assembly includes a drive rod 26 that is releasably held by a release assembly 46 a compressed coiled spring unit 30 drives the sleeve assembly 16 forward exposing the payload section 17 to the centrifugal force of the spin stabilized rocket propelling the NEI elements out from the rocket at constant angular velocity creating an interceptor cloud of elements.

Abstract: An indoor cellular band antenna has an outer metal housing having a 90° inner configuration and a radome positioned over the front of the housing. An antenna dipole is mounted in the housing and includes two dipole members. Each dipole member includes a rectangular dipole element extended transmission balun members and a back mounting plate. An antenna cable extends through the top panel of the housing. An outer conductor of the cable is electrically connected to one of the transmission balun member of one dipole member and an inner conductor is electrically connected to the dipole element of the same dipole member. The inner and outer conductors of the cable are mounted to the dipole member by connectors formed from the dipole member.

Abstract: Information is transmitted in an uplink to a satellite by applying an outer code to an information block to form an outer coded block. The outer coded block is then inner coded when a short block code is applied, thereby producing a concatenated coded block.

Abstract: A system and method for monitoring tread wear, shock absorber performance, balance condition of a vehicle tire, and/or rotation speed of a vehicle wheel, use a sensor to provide acceleration signals. To monitor tread wear, acceleration signals from the sensor determine at least one resonance frequency of at least one of the radial and lateral acceleration of the tire and compares it to at least one stored resonance frequency To monitor shock absorber performance, the amplitude of the Fourier component of the radial acceleration is compared to a stored amplitude value. To monitor a balance condition of a vehicle tire, the sensor provides acceleration signals measured over a specified time duration to determine an amplitude of the Fourier component of the radial acceleration that is compared to a stored amplitude specification balance condition of the tire.

Abstract: A rack (70) for a plurality of electronics modules (36) that does not include inlet and outlet air cooling plenums. The rack (70) includes a heat exchanger (72) including three separate sections (78, 80, 82), where each section (78, 80, 82) include spaced-apart parallel fins (84, 86, 88). First and second end sections (80, 82) of the heat exchanger (72) include cooling fins (86, 88) that extend parallel to each other in a front-to-back direction relative to the direction the modules (36) are slid into the rack (70). The first and second end sections (80, 82) are positioned at opposite ends of a center section (78), where the fins (84) of the center section (78) extend in a direction transverse to the direction the modules (36) are slid into the rack (70). The channels between the fins (86, 88) in the first and second end sections (80, 82) are aligned with inlet and outlet ports (94, 98) extending through a back panel (52) of the rack (70).

Abstract: A nulling direct radiating array (30) that includes a main phased array (32) and a plurality of auxiliary arrays (70, 72, 74) symmetrically disposed about the main array (32). The main array (32) includes a plurality of antenna elements (34) and a beam forming system (56) that generates one or more channels made up of several pixel beams. The pixel beams from the main array (32) are connected to a nulling processor (108) along with the combined signal from the antenna elements (80) of the auxiliary arrays (70, 72, 74). An adaptive weighting network (112) and an adaptive weight generator (114) within the nulling processor (108) determine whether a jamming signal exists in the channel beam, and weight the pixel beams from the main array (32) accordingly to block the jamming signal. The auxiliary arrays (70, 72, 74) provide a wider beam aperture that is able to more narrowly define the null in the radiation pattern of the main array (32).

Abstract: An apparatus and method for computing the average axis of rotation for a rotational device utilizes photogrammetric data derived from a rotational device in conjunction with an iterative algorithm to determine the average axis of rotation within a desired resolution. The input photogrammetric data is determined by photogrammetry. In particular, a target plate including a plurality of targets is installed on each rotational axis, the targets are photogrammetrically measured at an initial rotational position, the target plate is rotated to a different position and the targets are photogrammetrically measured at the new position.

Abstract: A load shedding method and apparatus to enhance uplink margin between a terrestrial terminal (14) and a satellite (12) in a satellite based communications system (10) is provided. The terrestrial terminal (14) includes a multi-carrier network (40) that generates a plurality of uplink carrier channels. A RF transmit and receive system (48) transmits the plurality of uplink carrier channels to the satellite (12). A terminal control unit (46) determines an attenuation level on the plurality of uplink carrier channels transmitted to the satellite (12). The terminal control unit (46) also instructs the multi-carrier network (40) to increase or decrease the number of uplink carrier channels to be transmitted to the satellite.

Abstract: A method and apparatus for emulating instructions of a microprocessor (“legacy instructions”) with an incompatible instruction set which provides increased throughput relative to known emulation systems. In particular, each word of legacy memory is translated into an opcode/operand field and a dual function vector/tag field. The vector field represent addresses to legacy instruction emulation routines. The tag field is indexed to table of “thunk” objects, which can be used for various purposes. Such purposes include a disabling part of the legacy software, augmenting the legacy software with native software, and gathering execution statistics without modifying the legacy software.

Abstract: A rack (70) for a plurality of internal electronics modules that includes a mechanism for mounting external electronics modules (69). The rack (70) includes a heat exchanger (63) disposed between the rack (70) and the external electronics module (69). The external electronics module (69) includes a heat coupling surface for efficiently using the heat exchanger (63) for dissipating heat of the external electronics module (69).

Abstract: A deployable phased-array-of-reflectors antenna includes individual reflectors and feed arrays. Each feed array is disposed above a corresponding individual reflector. The individual reflector antennas are preferably disposed adjacent to one another (e.g., on a hexagonal lattice) to form a phased array antenna using the individual reflectors antennas as elements. Phase and amplitude control electronics are coupled to each reflector antenna to provide steering for the signal energy coupled between the reflectors and the feed arrays. Switching electronics are coupled to the feed arrays and selectively activate and deactivate beam forming clusters of feeds in the feed arrays. A method for generating a steerable antenna pattern couples signal energy through a beamforming section to form steered signal energy. Next, the method couples the steered signal energy between a phased array of reflector antennas.

Abstract: An optical amplifier (20, 100) includes an elongated slab (22, 102) of solid state lapsing material, such as a rare earth doped yttrium-aluminum-garnet (YAG) slab. In order to provide a relatively increased absorption length and thus a higher overall efficiency, the optical amplifier (20, 100) in accordance with the present invention incorporates end pumping in which the pumped light is coaligned with the amplified light resulting in relatively longer absorption lengths and higher overall efficiencies. The coaligned pumped sources are directed to lateral faces of the slab (22, 102) which include footprints (41, 43, 108) or windows. In order to cause internal reflection of the pump beam along the lapsing axis, the end faces (28, 30, 110) are formed at about a 45° angle relative to the longitudinal axis which causes the pumped light to be reflected within the slab co-axially with amplified light.

Abstract: A channelizer for signals for optically channelizing RF signals modulated onto an optical carrier by optically separating the RF signals and mapping the RF signals by way of an optically dispersive element, such as a diffraction grating. In an alternate embodiment of the invention, two stages of optical filters elements are provided in series to perform sequential channelization. Bragg reflection gratings are used for coarse filtering into predetermined bands while Fabry-Perot filters tuned to specific sub-bands of the Bragg reflection gratings are used for channelization. In alternate embodiments of the invention, a silica planar waveguide and a optical splitting device, such as a Talbot splitter, are used.

Abstract: A wideband digital tuner (14′) has an analog front-end section (10), a high speed analog-to-digital converter (12), demultiplexer (13) and a plurality of filters (341-342) arranged in a parallel input architecture to process wideband digital data received at extremely high sampling rates, such as at 2 Gsps (giga-samples per second). The tuner greatly attenuates an undesired spectral half of the wide bandwidth digital spectrum of the incoming digital signal using a complex band-pass filter, such as a Hilbert Transform filter. The tuner places the remaining half of the wide bandwidth digital spectrum of the incoming digital signal at complex baseband and down samples by 2. The architecture of the tuner can be partitioned into two separate halves which are hardware copies of each other.

Abstract: The invention is a demodulator (50, 100) and a method of data reception and testing of a demodulator. A demodulator in accordance with the invention includes an input signal source (52, 102) having an output which during data reception is a data signal and which during testing of the demodulator is a reference signal; a tuner (54, 101) having a tuner input coupled to the output of the input signal source and a tuner output, the tuner including a frequency converter (20, 36) which frequency shifts the data signal to a lower carrier frequency during data reception to cause the tuner to output at the tuner output the lower carrier frequency modulated with the data signal and which upwardly frequency shifts the reference signal to a test carrier frequency during the testing; and a test data source (56, 105) which applies a test data signal to the tuner during the testing to cause the tuner to output at the tuner output the test carrier frequency modulated with the test data signal.

Abstract: An interferometer antenna system (32) for measuring the angle of arrival of RF signals. The interferometer antenna system (32) includes a plurality of interferometer antenna elements (36) coupled to a first switching network (42). The first switching network (42) is coupled to only two interferometer receivers (44, 46). The first switching network (42) selectively connects the plurality of interferometer antenna elements (36) in pairs to the two interferometer receivers (44, 46) in a sequential manner, so that a phase difference is measured between the received signal for several of the pairs of the interferometer elements (36). Additionally, a plurality of guard antenna elements (38) are coupled to a second switching network (48). A single guard receiver (50) is coupled to the second switching network (48), where the second switching network (48) selectively connects one of the guard antenna elements (38) to the guard receiver (50) in a sequential manner.

Abstract: An optical amplifier which includes an elongated slab of solid state lasing material, such as a rare earth doped yttrium-aluminum-garnet (YAG). In order to provide a relatively increased absorption length and thus a higher overall efficiency, the optical amplifier in accordance with the present invention incorporates end pumping in which the pumped light is coaligned with the amplified light resulting in relatively longer absorption lengths and higher overall efficiencies. The coaligned pumped sources are directed to lateral faces of the slab which include windows, formed from an insulating coating such as an anti-reflection coating, at the pump wavelength. In order to cause internal reflection of the pump beam along the lasing axis, the end faces are formed at about a 45° angle relative to the longitudinal axis which causes the pumped light to be reflected within the slab co-axially a with a amplified light.

Abstract: An improved lateral shearing interferometer system for use with an original optical wavefront and a displaced optical wavefront having a phase difference from the original optical wavefront is disclosed. It comprises a lateral shearing interferometer that responds to the original optical wavefront and the displaced optical wavefront and develops an optical interference pattern representative of the optical phase differences. An optical detector located at the focal plane of the optical interference pattern provides a selective array of electrical signals representative of separated portions of the interference pattern. A data processor is programmed to indicate the separated portions of said interference pattern, which has pixels in non-adjacent locations in odd rows and no pixels in even rows. The pixels correspond to locations of actuators for correcting the phase difference.