Abstract: A monopulse system generates sum (.SIGMA.), elevation difference (.DELTA..sub.EL), azimuth difference (.DELTA..sub.AZ), and double difference (.DELTA..sub..DELTA.) signals, and generates a covariance matrix. The covariance matrix is decomposed to produce at least the principal eigenvector. The location or angular direction within the main beam of a single target is determined from the real component of the quotient of elements of the principal eigenvector, by the use of a look-up table. In another embodiment of the invention, the eigenvalues are generated from the covariance matrix, and the number of significant eigenvalues determines the number of targets within the main beam. If a single target is found, its location is found as described above. If two targets are found in the main beam, the locations of the two targets are determined by a closed-form solution of quadratic equations.

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: A method for forming coatings of constant thickness on sheets of dielectric substrate (10), which may be curved, includes the step of adhesively applying foil (12) to one side of the dielectric substrate. An electrode (16) is set at a constant distance (D) from the side (10fs) of the substrate to be coated. If the substrate is curved, the electrode is preferably also curved. The region to be coated is evacuated, gaseous precursor materials are infused into the gap, and voltage is applied between the foil (12) and the electrode (16) sufficient to ionize the precursors to a plasma state, whereupon the deposition occurs. The foil may be applied as an adhesive-backed foil. The adhesive may be electrically conductive.

Abstract: A radar or GPS receiving system uses an antenna array to produce multiple antenna beams directed toward multiple targets or spacecraft. Stand-off jammers produce signals which tend to be received on the sidelobes of the antenna beams and to disrupt system operation. An array of autonomous or adaptive nullers process the received signals to produce weights which adjust the antenna nulls to direct them toward the jammers. The antenna nulls of one beam pattern are compared with the nulls of other beam patterns. Normal between-sidelobe nulls will not occur at the same angle on all of the patterns, but those nulls generated by the nullers will occur at the same angle. The directions to the jammers are deemed to be those directions in which all beam patterns have nulls.

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: A near-field calibration arrangement for a phased-array antenna 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.

Abstract: In a vocoder system, the receiver is arranged to emphasize at least the fundamental or lowest-frequency sinusoidal signal in response to the pitch, in a manner which provides more emphasis at lower pitch values, corresponding to larger pitch intervals. The emphasis provides a subjectively improved speech synthesis. In a preferred embodiment, the enhancement takes place at fundamental component frequencies below 400 Hz. According to another aspect of the invention, the second and third harmonics are also emphasized, but generally not as much as the fundamental component. Below certain frequencies, the enhancement is limited for the fundamental and the harmonics.

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 method for fabricating a printed-circuit board includes the steps of loading components onto the printed circuit board, and placing a pin array over the components. Each pin is free to move "downward," and each component has at least one pin pressing on it to hold the component in place. Each component also preferably has a pin on each side of it, to hold it against lateral movement. The pin support arrangement is dimensioned so that a gap or space exists between the support and the component side of the board. Heat is applied to the gap, and flows through the interstices between the pins to heat the solder on the upper side of the board to fuse the solder and make the desired connections.

Abstract: A number N of AC machines, such as motors or generators, are independently controlled by a control system having 2N+1 phases, having N orthogonal sets of phase components. In a particular application, a hybrid vehicle including a generator and an induction motor are independently controlled by a five-phase controller having two independent sets of mutually orthogonal components. Each set of components controls one of the machines, and has no net effect on the other machine(s).

Abstract: A spacecraft cellular communication system (10) includes a spacecraft (12) with an antenna (12a) which produces multiple "spot" beams (20a, 20b, . . . ) for serving user terminals (16) lying in the footprints (20af, 20bf, . . . ) of the beams. The communication system is controlled by a network control center (NCC 18), which produces forward control signals (608, 611, 613). The forward control signals include high-margin (H) portions and lower-margin (LM) portions. In order to minimize the power required to transmit the forward control signals from the spacecraft, the number of forward control signal carriers is limited to one per antenna beam. In order to minimize the peak-to-average power requirement placed on the spacecraft power source (12s, 12pc), the high-margin portions (H) of the forward control signals of the various antenna beams are mutually offset in time or time-interleaved.

Abstract: A vocoder transmitter (12) sends coded speech to a vocoder receiver (16) over a limited-bandwidth channel (14). The transmitter includes a LPC-residual-based first gain estimator (46), which gain value works well with women's voices, but less so with men's. A second, analysis-by-synthesis, gain estimator (42) therein, uses a unit-gain version (342) of the receiver's synthesizer, whose input (24) and output (310) speech power is estimated, to produce the second gain value from their ratio (312). The second gain value has been found to work well with men's voices, but to produce "explosive" artifacts with women's. A combiner (518) weights these two gain estimates, under control of the estimated pitch, to produce the vocoder gain estimate transmitted to the vocoder receiver (16). In a particular embodiment the first gain estimate predominates at low pitch periods, and the second gain estimate at higher ones, with crossover at about 45 sample lags for an 8000 Hz sampling rate.

Abstract: A planar spiral antenna is fed from the outer end, and one embodiment includes a capacitive plate adjacent the interior end. Two such planar spiral antennas are arrayed over a ground plane by the use of a phase shifter which provides a 90.degree. phase difference between the two elements of the array. In this array, the rotational positions of the arrays differ by 90.degree.. Two such two-spiral arrays are arrayed together, with elements of like phase delay diametrically opposite to each other in the overall array. This overall array has two feed ports, which are fed in parallel.

Abstract: An electric vehicle (10) includes a traction motor (26) which drives the wheels (30a, 30b) by way of a differential (28), if desired. The traction motor (26) is controlled by a controller (24) which responds to torque command signals, to cause the motor (26) to produce the commanded torque. An accelerator pedal (12) is coupled to a position transducer (16) which converts pedal position into digital signals. The digital signals representing pedal position are applied as addresses to a memory (22) to access the stored signals. The memory is preprogrammed with torque signals representing the torque desired at a given pedal depression. In a preferred embodiment, the preprogrammed signals represent torques which are monotonically related to the pedal position, although some deviation may be acceptable in small portions of the operating range. The memory signals resulting from a given pedal position are applied to the controller, for causing the controller to command the motor to produce the specified torque.

Abstract: A low-profile transformer or inductor includes a leg of a magnetically permeable core. A tube-type winding arrangement is made by use of a flat, flexible dielectric sheet, on one side of which a broad conductive area is affixed, and on the other side of which a plurality of mutually parallel elongated regions are affixed. The dielectric sheet is rolled into a tube defining a parting line which is perpendicular to the axes of elongation of the conductive strips. The discontinuous elongated strips are formed into a continuous winding by means of stitches. The stitches may be through vias extending through overlapping regions of the tube to interconnect ends of the strip conductors, or may be generated by an HDI conductor overlying the ends of the strip conductors, with through vias making connections to the ends of the strip conductors and to HDI conductors.

Abstract: A portable illuminator for use in an atmosphere of fog, haze or particulate matter includes a laser for generating a light beam, and a light-beam scanner for scanning the laser beam over a line or area to be illuminated. The scanning may be accomplished by mechanically moving the mirror or the laser, or a moving lens may be used. In another embodiment, a microelectronic scanning reflector is used.

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 way of electrically conductive, compliant fuzz buttons. The transmission path may be a coaxial path useful for RF.

Abstract: A spacecraft-based cellular communications system includes a spacecraft with transmit and receive antennas, each of which produces a plurality of spot beams which, together, provide coverage of the region served. In order to control the pointing of the spacecraft antennas, four mutually adjacent spot beams are centered over a particular "beacon" location, so that the beacon location lies between a pair of North and South spot beams, and between a pair of East and West spot beams. The transmit antenna is controlled by transmitting a beacon signal in time sequence over each of the four spot beams surrounding the beacon location, and decoding or desequencing the time-sequential signal received at the beacon location. The decoded signal is processed to provide a signal indicating the pointing error of the transmit antenna, and the error signal is used to control a gimbal which controls the pointing of the transmit antenna.

Abstract: Intelligent mobile agents in a distributed network carry information tokens among network nodes. Each token includes compressed information or data, and an indication of the compression algorithm which can decompress the information. At least some of the nodes have at least one decompression algorithm. A copy of a token may be left at a node by an intelligent mobile agent moving through the network. A later-arriving intelligent mobile agent can interrogate the node to determine what information it has in the form of tokens, and can use the token information, or take the token (or a copy) elsewhere.

Abstract: Aluminum-lithium alloy sheets which are welded together are examined to identify regions requiring repair. A grid is applied to the sheet about the region requiring repair, and the region to be repaired is ground out and rewelded. Residual stresses are relieved by planishing yes to cause localized plastic deformation in the repaired region. The grid is used as a guide to restoring the original dimensions of the sheet in a manner which tends to reduce in-plane shrinkage. The reduced in-plane shrinkage in turn tends to reduce undesired tensile residual stresses. The planishing also tends to work-harden the weld filler.