Abstract: An antenna comprising a substrate, and low band and high band opposite sense spiral antennas formed on the substrate to provide for a common aperture isolated dual frequency band antenna. The high band spiral antenna is formed adjacent the center of the substrate while the low band spiral antenna is formed adjacent the periphery of the substrate. The high frequency end of the low band antenna is truncated at the low frequency end of the high band antenna, and the low frequency end of the high frequency antenna is truncated at the high frequency end of the low band antenna 21 to provide for mutual isolation between the frequency bands.

Abstract: A common aperture dual polarization array that comprises a vertical polarization antenna array that provides for vertical polarization, and horizontal polarization antenna array that provides for horizontal polarization. The vertical polarization antenna array is comprised of a flat plate shunt slot standing wave array that includes a plurality of sets of radiating slots configured in a staggered pattern that are laterally separated by an air gap. The horizontal polarization antenna array is comprised of a collinear array of radiating slots, a strip reflector, and a plurality of baffles that form a short backfire antenna array. The collinear slots are disposed orthogonal to the radiating slots of the vertical polarization antenna array.

Abstract: A weapon station testing system for testing the mission readiness of an aircraft (10) having a plurality of weapon stations including a first weapon station (12a) and a second weapon station (12b) comprises a common electronics module (14) and a plurality of interchangeable mechanical fixtures (16a, 16b). A first interchangeable fixture (16a) is operative for interconnecting the common electronics module (14) with the first weapon station (12a). A second interchangeable fixture (16b) is operative for interconnecting the common electronics module (14) with the second weapon station (12b).

Abstract: A neural processor element for use in a neural network includes a synaptic base weighting circuit which responds to an excitory input in the form of a stream of pulses of a first polarity which represents a sum of synaptic weights and an inhibitory input in the form of a stream of pulses of a second polarity which represents a sum of synaptic weights. The synaptic weight of the neural processor element is generated by summing the excitory and inhibitory pulse streams to produce a signal of varying level magnitude. This signal is subjected to a thresholding function which generates a pulse having a width corresponding to the sum of excitory and inhibitory pulse streams, this pulse width representing the synaptic weight for the neural processor element.

Abstract: A wire antenna having a Vivaldi taper that is used to radiate or receive low frequency RF energy from or to an airborne platform. The antenna comprises two conducting wires that trail from the platform, and which comprise a radiator having a Vivaldi taper. The shape of the conducting wires is maintained by a combination of aerodynamic drag on the conducting wires, a weight connected to the end of the lower wire, a chute connected to the end of the upper wire, and nonconducting guy-wires connecting the upper and lower conducting wires. The nonconducting guy-wires are positioned at locations between the upper and lower conducting wires to form and maintain an optimal taper between the conducting wires. A method of deploying a Vivaldi antenna from an airborne platform is also disclosed. A lower conducting wire is attached to the enclosure, and an upper conducting wire is attached to a chute. The antenna and chute are stored in the enclosure, and the enclosure is disposed beneath the platform.

Abstract: Blended missile autopilots for a missile employing direct lift and tail controlled autopilots coupled by way of a blending filter. The blended missile autopilots have movable tails aft of the center of gravity of the missile and side force thrusters or movable canards mounted forward of the center of gravity, and that are controlled using the direct lift and tail-controlled autopilots. Lift is generated from the tails and side force is generated by the thrusters or canards, such that the body of the missile maintains zero angle of attack and generates no lift. The present invention thus combines the fast response of a direct lift autopilot with the high acceleration capability of a body lift autopilot, and blends the two using the blending filter to achieve improved performance.

Abstract: A stepped beam transmit antenna that comprises a feed array that includes a dielectric substrate and a plurality of radiating elements disposed on the substrate. The radiating elements each comprise two coplanar and coextensive fins that are separated by a narrow gap and that are tapered at their radiating end to form a linear tapered slot feed aperture. Beam position inputs are disposed at respective input ends of each of the radiating elements. A backshort is disposed adjacent the tapered slot feed aperture of each of the radiating elements. A low pass filter is disposed adjacent the backshort of each of the radiating elements. A switching diode is disposed between the backshort and the tapered slot feed aperture of each of the radiating elements. The antenna includes a power distribution network comprising a suspended printed line. A lens is disposed adjacent the feed array for projecting energy beams produced by the antenna.

Abstract: A method and apparatus for flying a folding fin from a stored folded position on a flight vehicle housing to a deployed erect position, using available aerodynamic or fluid forces to control the fin deployment. The fin is erected in several stages. First, a hinge spring bias or lifting wedge means, or combination of fin and body shape, raises the fin surface sufficiently to engage the high-speed fluid flow over the vehicle housing. Next, a motion sensor measures the fin erection angle. Finally, a feedback control system adjusts the fin control angle to increase or reduce the time rate of change of fin erection angle, as necessary. In this manner, the fin can be "flown" into its deployed position in a smooth and controlled manner whereupon it is locked into the deployed erect position on the vehicle housing.

Abstract: A shielding gasket is disclosed which may be installed between a door panel and an enclosure containing electronic equipment therein, the shielding gasket providing excellent electromagnetic shielding effectiveness in the space between the door panel and the enclosure. The shielding gasket includes a retaining medium for holding a corrosion-inhibiting fluid, which is bled from the retaining medium onto the outer surface of the conductive gasket over an extended period of time to provide a protective film over the interfacing dissimilar metals of the shielding gasket and the enclosure. The shielding gasket may include an elastomeric gasket to provide a moisture-proof seal, or a rigid metallic strip to support the shielding gasket.

Abstract: Apparatus and method for conveying information from an object by delayed reflection of an interrogating ultra-high range resolution radar signal which is digitized into a series of programmable spaced pulses by an electronic license plate circuit. The electronic license plate includes a plurality of unique programmable delay lines connected through a coupler network to an antenna.

Abstract: A short-term thermally stable cryostat (40). The cryostat (40) pre-cools an incoming high-pressure gas, converts the gas to a cold liquid, and cools an item by allowing the liquid to acquire heat from the item and boil into an exhaust gas, while maintaining a constant flow rate of the exhaust gas to reduce thermal noise due to flow rate modulation. The cryostat (40) includes an evacuated space (58) therein containing the item to be cooled and an inner cooling volume (64). Pre-cooling fins (44) spiral around a hollow mandrel (52) within the cooling volume (64) and circulate an incoming high-pressure gas around the mandrel (52). A flow restrictor (60) receives the incoming gas from the pre-cooling fins (44) and releases it into the cooling volume (64), thereby convening the incoming gas into a cold liquid which can acquire heat from the item and boil into an exhaust gas.

Abstract: Disclosed is a self-surveying relative GPS (Global Positioning System) weapon guidance system (10). This guidance system (10) includes multiple GPS satellites (12-18) which transmit GPS data to a ground sensor (20). The ground sensor (20) includes a GPS receiver (24), a self-surveying computer (28), a data formatter (30) and a transmitter (32). The GPS receiver (24) receives the GPS data and determines a second location of the ground sensor (20) based on the GPS data. The self-surveying computer (28) determines a first location of the ground sensor (20) based on the GPS data gathered over time, which is more accurate than the second location. The data formatter (30) determines a GPS error between the first and second locations which is transmitted by the transmitter (32). The GPS error is used by guided weapons in the vicinity of the ground sensor (20) to substantially increase the delivery accuracy of the guided weapons (40).

Abstract: A self-calibrating pulse compression system which is able to optimally compress a chirped waveform notwithstanding variations in the chirped spectrum due to changes in transmitter characteristics or other factors. In a most general sense, the inventive pulse compression system includes a first circuit (12, 14) for providing a first waveform, a second circuit (16, 30, 32) for sampling the first waveform at predetermined time intervals to provide a plurality of calibration samples, a third circuit (30) for storing the calibration samples; and fourth circuit (16, 28, 30) for multiplying a second waveform by the stored calibration samples. In a specific implementation, the first circuit of the self-calibrating pulse compression system includes an impatt chirp transmitter (12). The output of the transmitter (12) is fed to an antenna (18) and to a first switch (22) by a circulator (20). The switch (22) is controlled by a timing circuit (16) which may be implemented with software in a host computer.

Abstract: An apparatus for winding a coil pack of a fiber such as an optical fiber winds the fiber as a radial coil, and then joins the coil axially to previously wound coils. Each radial coil is wound on a flexible flange that is deformable from a first tapered shape which facilitates the winding against the flange, to a second shape wherein the coil wound thereon conforms to the shape of the last coil affixed to the fiber pack. The flexible flange is preferably made of an elastomer, and its shape change is readily accomplished by an articulated series of nesting cylinders. The apparatus further includes a fiber winding head that winds the fiber onto the flexible flange, and an adhesive applicator head that applies adhesive between succeeding coils of fiber as they are joined to the coil pack.

Abstract: A demand-flow Joule-Thomson cryostat 10' adapted for use with multiple coolants uses a replaceable coolant supply reservoir 21' to fill a coolant flow control bellows 17' within the cryostat with the same coolant used to provide refrigeration to the thermal load 15'. Upon termination of the cooling cycle, the bellows 17' is drained of coolant and thus prepared for operation from a different coolant supply 21' that may contain a different cryogen.

Abstract: A process for repairing leaking glass-to-metal seals of a hybrid microcircuit header. The process comprises the following steps. A leaking hybrid microcircuit header is delidded (has its lid removed). The leaking hybrid microcircuit header, generally with its leads pointing vertically, is disposed on a vacuum source. A vacuum is formed on the hybrid microcircuit header using the vacuum source. A stream of helium is flowed over the seals to verify the presence of leaks in the seals of the hybrid microcircuit header. A small amount of high vacuum sealant is applied to each of the leaking glass-to-metal seals while the hybrid microcircuit header is exposed to the vacuum. The vacuum draws the sealant through the cracked or defective glass-to-metal seals. The high vacuum sealant generally comprises a silicone resin having a low vapor pressure. A stream of helium is caused to flow over the resealed leads following application of the high vacuum sealant to confirm that the hybrid microcircuit header is sealed.

Abstract: A millimeter wave device having a dielectric substrate with a pair of substantially parallel planar surfaces with at least one predetermined millimeter wave circuit pattern formed in a conductive layer located on at least one of the substrate surfaces. A substantially planar conductive channel plate is mounted adjacent the conductive layer on one substrate surface with the channel plate having an aperture overlying each circuit pattern formed in the conductive layer. A substantially planar conductive cover plate is mounted adjacent one of the channel plates so as to form a first cavity in the region defined by the substrate surface, the channel plate aperture and the cover plate. The device may further include a second substantially planar conductive channel plate mounted adjacent the other one of the substrate surfaces with the second channel plate having an aperture corresponding to and aligned with the first channel plate aperture.

Abstract: A dual polarization array that comprises horizontal polarization and vertical polarization arrays, combined with an efficient waveguide-fed standing wave feed array. The vertical polarization array comprises an offset, resonant, iris-fed, centered longitudinal-shunt-slot, standing wave array. The horizontal polarization array comprises a flared dipole fed by a longitudinal, shunt-slot, standing wave array. The waveguide-fed standing wave feed array is comprised of a plurality of waveguides that separately feed the horizontal polarization and vertical polarization arrays. The horizontal polarization array comprises a first plurality of radiating waveguides laterally disposed adjacent to each other that are separated by a first plurality of gaps. Each waveguide comprises a plurality of radiating flared dipoles disposed adjacent to a respective plurality of longitudinal radiating shunt slots.

Abstract: An undersea vehicle storage and ejection system includes a capsule having a cavity therein adapted to store and launch a vehicle. The capsule has an opening at one end for passage of the vehicle therethrough. A closure member is suitably adapted to be mateable with the housing at the opening to seal the cavity. A rocket unit is incorporated within the capsule to remove the closure member at launch. The closure member includes a sealing arrangement for withstanding the hydrostatic pressure when the system is in the undersea environment of use and block the entry of sea water into the cavity. The rocket unit, when ignited, rapidly builds up pressure within the capsule to a level exceeding the external hydrostatic pressure on the cover, thereby removing the cover so that the vehicle may be launched.

Abstract: An autonomous bomb damage assessment system that is piggybacked to a bomb to provide imagery of a bombed area immediately after bomb delivery. The bomb damage assessment system comprises a housing that is releasably secured to the bomb. An imaging system is disposed at one end of the housing and a folded inflatable balloon is disposed at the other end of the housing. An inflation device is provided for inflating the balloon with a lighter-than-air gas such as helium. A proximity fuze is used to sense the location of the ground, for causing the system to be ejected away from the bomb shortly before bomb impact, and for causing the inflation device to inflate the balloon. A data link is disposed in the housing for transmitting images derived from the imaging system to a remote location. The present invention provides imagery of a bombed area immediately after bomb delivery. The lighter than air characteristic of the system allows a dwell time over the bombed area so debris and dust can settle.