Abstract: Communication architectures and methods that implement random phase shift keying. A transmitter and a receiver are coupled by way of a communications channel. The transmitter uses a data source and a mapper that produces an amplitude phase keyed (APK) waveform having a plurality of symbol phases. A transmitter multiplier multiplies random phase signals with the APK waveform to produce a random phase keyed output signal. A vector modulator modulates the random phase keyed output signal. A transmitter mixer mixes the random phase keyed output signal with a local oscillator signal from a transmit local oscillator to produce a modulated carrier signal that is transmitted over the communication channel. The receiver has a demodulator including a receiver mixer that receives and mixes the received modulated carrier signal with a local oscillator signal derived from a receive local oscillator to produce an estimate of the random phase keyed signal. The estimated random phase keyed signal is synchronously sampled.

Abstract: A rocket engine (10) generates a flow of hot propulsion fluid through a nozzle (14N). Hybrid exhaust gas generators (36,38) have their exhausts (44,54) through the side of the nozzle. Each gas generator includes a fuel grain (46,56) and a source of oxidizer (16,40,50). The fuel grain is kept hot by either or both (a) direct radiation or conduction from the hot propulsion fluid, or (b) by a trickle of oxidizer. When the thrust vector is to be modified, the appropriate one of the hybrid gas generators receives a flow of oxidizer, and the resulting exhaust gas is injected through the side of the nozzle.

Abstract: A method is described which enables the location of a radio frequency emitting target in absolute or relative GPS coordinates from a single airborne platform within a few seconds. The method uses a signal processing technique which emulates an antenna moving at very high velocities to induce a Virtual Doppler shift on signals incident upon a linear antenna array. The Virtual Doppler shift is directly proportional to the signal direction of arrival as measured by its direction cosine. The method is shown to prevent single and multiple GPS jammers from being able to jam conventional GPS signals. Also disclosed is a means and method for developing virtual Doppler shifted signals to determine the angle-angle bearing of emitting targets to high resolution. This in turn, allows the position of the emitter to be determined in a GPS reference frame to be located to a high degree of accuracy from a single platform in extremely short times.

Abstract: Interconnections are made through a planar circuit by a monolithic short-circuited transmission path which extends from a circuit portion of the planar circuit to the opposite side. The opposite side is ground sufficiently to remove the short-circuiting plate, thereby separating the previously monolithic conductors, and exposing ends of the separated conductors of the transmission path. Connection is made between the exposed conductors of the transmission path and the registered contacts of a second planar circuit by means of electrically conductive, compliant fuzz buttons. The transmission path may be a coaxial path useful for RF.

Abstract: In a first aspect, the invention uses the thrust and axial aerodynamic forces of and on the missile system as the primary mechanism for altering the missile system's flight path as opposed to the missile system's aerodynamic normal force. In accordance with this first aspect, a first embodiment is a method for changing the direction of travel of a vehicle moving through a fluid medium to a desired direction of travel measured in the vehicle's inertial frame of reference, the vehicle comprising a body including a nose, a moment generating control device, and an axial propulsive device. The method comprises actuating the moment generating control device to align the nose substantially with the desired direction of travel, and applying the axial propulsive device as the primary mechanism to redirect the vehicle's velocity to the desired direction of travel. In a second aspect, the invention provides a missile control system implementing the first aspect of the invention.

Abstract: A method according to an aspect of the invention, for interconnecting electrical contacts or electrodes (230be) of semiconductor chips (230a, 230b, 230c) in an HDI context, includes the step of applying laser energy to make a pattern of apertures through a dielectric film which corresponds to the ideal locations of electrodes of semiconductor chips properly placed on the film. This may be accomplished, in one mode of the method, by procuring an optical mask (20) defining an ideal pattern of electrodes of semiconductor chips properly aligned in an HDI structure. This mask may be sufficiently large to cover a plurality of HDI circuits being made on a substrate, or it may cover only one such HDI circuit. Laser energy (30) is applied to a dielectric film (10; 10, 17) through apertures or transparent regions (22) of the mask, to thereby make the ideal pattern of holes in the film.

Abstract: A satellite cellular communication system includes terrestrial user terminals and gateways, which are interconnected, at least in part, by communications over antenna spot beams produced by the satellite. Various control signals and information signals traverse the system. The processing is simplified at the terrestrial terminals by adding dummy bits to the call maintenance signals, and processing them to equal the frame size of the traffic signals, and by encoding the call maintenance signals using the same algorithm as that used to encode the traffic signals. The call traffic signals are separated from the call maintenance signals, after decoding the frames in a common manner, by (a) identifying as traffic signals those frames in which error detection and correction (EDAC) identifies no error, and in which the 27 bits added to the call maintenance signals do not match the added-bit pattern.

Abstract: A method for welding a first metallic material to a second metallic material where at least one of the first and second metallic materials have at least one surface which has an optical pattern thereon. The method comprises the steps of: arranging the first and second metallic materials into a final position in which they will be welded along a joint; directing focused energy at the joint from a Nd-YAG pulsed laser having an energy output in a range from about 10 Joules to about 30 Joules and a pulse length in a range from about 5 ms to about 9 ms; and traversing the joint at a predetermined welding speed while directing the focused energy such that a weld spot overlap in a range from about 50% to about 90% is maintained, resulting in a welded joint wherein a heat effect zone about the welded joint is minimized further resulting in minimal distortion and damage to an area of the optical pattern proximate to the welded joint.

Abstract: A method for making an HDI-connected circuit is described, which in a simple manner allows an air pocket, space, gap, or bubble to be formed over pressure- or dielectric-sensitive portions of a semiconductor chip. The method applies a layer of uncured adhesive over a dielectric film, and also over any electrical conductors deposited on the film. The adhesive is exposed through a mask to a laser beam, which selectively vaporizes the adhesive in the exposed regions, to define the air pocket region. The semiconductor chips are applied, electrode-side down, on the adhesive, with the sensitive regions registered with the pockets. The adhesive is cured, and conductive vias are formed through the dielectric film and the adhesive to make contact with the electrodes of the semiconductor chips. Other layers of HDI interconnect are then applied over the dielectric film, and interconnected by vias, if needed.

Abstract: A spacecraft cellular time-division multiple access (TDMA) communication system (10) includes a spacecraft (12) with an antenna (12a) which produces multiple beams (20a, 20b, 20c) in different directions, to form footprints (20af, 20bf, 20cf) at different locations, including the nadir (3) and the horizon (5). User terminals (16a, 16b, 16c) in each footprint (20af, 20bf, 20cf) transmit reverse control signals (312) as bursts in TDMA time slots over uplinks (106, 110, 114), which are routed by the spacecraft to a network control center (NCC 18), to aid in controlling the operation of the system (10). The NCC (18) receives the bursts within receive time slots (310, 314, 316) which have durations which depend upon the origin of the reverse control signals.

Abstract: Apparatus and method for fabricating a backside illuminated photodiode array is described which does not use epoxy, and therefore has better transmission characteristics. The method uses indium or other coldweldable metal to fasten the detectors to the transmissive substrate. Because the indium is opaque in the waveband of detector sensitivity, it also forms an optical mask for each detector element.

Abstract: A high resolution, high speed digital camera that produces a high resolution image representative of an image scene viewed by the camera. The digital camera comprises an input lens system and an iris that couple light from the image scene into the camera. A first imager generates a sequence of high resolution, low speed digital frames of the image scene. A second imager generates a sequence of low resolution, high speed digital frames of the image scene.

Abstract: A coherent, frequency agile pulse radar system in which each transmitted pulse is made up of subpulse pairs having frequencies of &ohgr;o±&Dgr;i forces a jammer to broadband jam the system in order to ensure jamming the actual operating frequency of the system. On reception, a separate receiver channel is utilized for the detection of each subpulse frequency. Within the processing system, the signal return for a subpulse having a frequency of &ohgr;o+&Dgr;l is multipled times the signal return for the subpulse having a frequency of &ohgr;o−&Dgr;l to provide a combined signal which is free of the offset frequencies. This combined signal is a standard coherent frequency agile pulse doppler radar signal with the exception that the carrier frequency and the doppler frequency are both doubled. Moving target indicating or doppler processing may be used.

Abstract: A route planning algorithm for a vehicle takes into account the aspect angle which the vehicle presents to threats in the environment. A flag is set in each map grid cell for which intervisibility with a threat exists. For each cell in which the flag is set, an aspect angle pointer points to a mathematical function which represents the cost value function attributable to the type of vehicle, the type of threat, and the aspect angle of the path segment. A determination is made as to whether an auxiliary function representing the probability of the threat is associated with the cell under consideration, and if so the auxiliary function is evaluated. If the result of the auxiliary function is nonzero, the aspect angle function is evaluated, and added to the map cost function to form a total cost. If not, the route planning algorithm continues without taking aspect angle into account. If so, the route planner uses the total cost.

Abstract: A processor-based system performs overwatch location and routing determinations for plural independent entities acting as a team. The system accepts data representing a “map” and uses that portion including the objective location or direction, together with data about known features of the environment and the capabilities of the team entities. An initial coarse route is inputted. The data is processed by designation of one of the team members as the overwatcher, and the other as the bounder. The procedure includes the steps of determination of an area to which bounding is permitted, and pruning out those grid cells in that area which cannot be seen from the first overview location. For the remaining grid cells of the pruned set, a cost function is determined for each remaining grid location.

Abstract: A reflective modulator (10) includes a light splitter (12) which divides light into two portions, one of which is applied to a directional coupler (14) by a first path (20), and the other of which is applied to the directional coupler (14) by way of cascaded electrooptic (e-o) modulators (18a, 18b). One port of the directional coupler (14) is terminated in a reflector (22), and the other in an absorptive termination (24). Electrical signals A and B are applied to the modulators (18a, 18b), with the result of generation of sum and difference frequencies modulating the light. The light leaves the reflective modulator (10) and is coupled to a utilization apparatus (64) by a second directional coupler (28). A further e-o modulator (26) may be coupled in the first path, for controlling the long-term average phase shift. In a particularly advantageous embodiment of the invention, the signal sources (30a, 30b) are elemental antennas of an array (30).

Abstract: A seam (16) between juxtaposed workpieces (14) is welded or heat-treated by friction-stir using a pin tool (12) driven by an apparatus (18) which controllably positions the pin tool (12) in the vertical direction (8). The workpiece (14) is supported by an anvil (22). The joint is heated by rotation of the pin tool (12) inserted into the joint from the obverse side. In order to provide a good weld through the thickness of the workpiece, a sensor (34, 310) senses electrical characteristics near the heated or welded region, and generates a control signal which tends to control the position of the pin tool near the reverse side of the weld. The sensor is located adjacent the weld (16s) on the obverse side, and is preferably protected by mounting in a depression (22c) in the anvil (22). In one embodiment, the sensor (34) senses magnetic characteristics near the weld. In another embodiment, the sensor (310) senses conduction, conductivity, or eddy currents in the vicinity of the weld.

Abstract: A near-field calibration arrangement for an antenna array determines the phase shifts or attenuation of the elemental control elements of the array. The calibration system includes a probe located in the near field, and a calibration tone generator. The tone generator is coupled to the probe in the case of calibration of a receive antenna, and to the signal port of the array in the case of calibration of a transmit antenna. A code generator generates sets of values, with each set being orthogonal to the others. The codes are applied to the control input port of the array antenna, so that the codes encode the tone passing through the antenna. The encoded tones are applied to a decoder and processor, which processes the signals to determine the phase shift or attenuation associated with each bit of the control signal. A transmit antenna attitude determination or pointing arrangement uses the calibration tone generator in conjunction with a plurality of remote sites.

Abstract: A sigma-delta analog-to-digital feedback converter arrangement (10) achieves low noise and a wide dynamic range by use of a directional coupler (18) as a summing device for generating the difference signal on which the forward sigma-delta analog-to-digital converter (32) operates. The feedback is provided by a digital-to-analog reconstructor (36), which applies the reconstructed analog signal to the tap (18.sub.3) of the directional coupler (18), in which the feedback signal is summed with the analog input signal. A low-noise amplifier (28) is coupled to the output of the directional coupler (18) at which the difference signal appears, so the dynamic range of the signal traversing the low-noise amplifier is small. The high isolation between the tap (18.sub.3) of the directional coupler (18) and the source of analog signals allows the use of an input bandpass filter (16).

Abstract: A launch system for plural missiles of different types includes plural launch locations, each adapted for receiving a canisterized missile having a standardized connector, which is coded to indicate the missile type contained within the canister. The system includes an individual fire control unit for each launch location or cell, and power supplies which are available to groups of such cells. An local-area network (LAN), such as Ethernet, interconnects the power supplies, the fire control units, and a central launch control system. Each fire control unit includes a processor for determining the missile type with which it is associated, and an interface card for each different missile type which may be used. The fire control units respond to commands from the central launch control system by interpreting the commands into a parallel form understandable by the missile interface cards.