Abstract: A surface acoustic wave (SAW) chirp signal processor having a piezoelectric substrate, an array of input transducers and an array of output transducers. In its chirp compression mode, the device has chirp signals applied in parallel to its input transducers and produces compressed output pulses at its output transducers, corresponding to selected chirp rates. The input transducers are successively offset with respect to a focal point on the array of output transducers, by distances that successively and linearly increase or decrease from transducer to transducer, consistent with the increase or decrease in the wavelength of the chirp signals. The device may also be used in a pulse expansion mode, by inputting a broadband pulse into a selected one of the output transducers. The input transducers then produce a chirp signal having a rate corresponding the selected to output transducer.

Abstract: A technique using pseudo-satellites, or "pseudolites," for resolving whole-cycle ambiguity that is inherent in phase-angle measurments of signals received from multiple satellite-based transmitters in a global positioning system. The relative position of a secondary receiving antenna with respect to a reference antenna is approximately known or approximately initially determined and then measurements from a minimum number of satellites are used to determine an initial set of potential solutions to the relative position of the secondary antenna that fall within a region of uncertainty surrounding the approximate position. Redundant measurements are taken from one or more pseudolites, and used to progressively reduce the number of potential solutions to close to one.

Abstract: This invention discloses a processing structure, and related method, for performing a selected data processing function by means of multiple processing modules that are selected to perform the selected function when appropriately connected together. The modules are removably connected to a common structure, such as a circuit board, which has associated with it a crossbar switch for providing intermodule data connections necessary for performing the selected function, and a synchronization unit for providing control signals to the modules to keep them in appropriate synchronism for performing the selected function. Convenient reconfiguration of the structure is effected by conditioning the crossbar switch and the synchronization unit as necessary to perform the different function.

Abstract: A system for creating discount coupons in response to the purchases of products. Improvements disclosed include the printing of a "negative" coupon in response to the failure to purchase a particular product, and the printing of a coupon in response to the purchase of multiple triggering items, either without limitation as to the identification of the items, or with the requirement that the items fall into a predefined trade group. Other features of the invention permit the use of instantly redeemable "coupons," such that an instant discount is applied to a customer bill rather than having a coupon printed, and the logging, without printing, of possible coupon printings for statistical purposes.

Abstract: A suction fitting for use in a water circulation system in which operation of a circulating pump is controlled to prevent damage to equipment and property and also to minimize the possibility of serious personal injury or death. The suction fitting includes a suction line connected to the pump, for circulating water in the tub or spa back through jets in the tub or spa, a pressure sensor line connecting the water in the tub or spa to a water level sensor, and one or more slots for water communication between the pressure sensor line and the suction line. When flow into the suction fitting is blocked, water is drawn out of the pressure sensor line and through the slots to the suction line, to permit detection of the blockage in the level sensor. The combination of the suction fitting, the pump and the water level sensor turn off the pump when the suction fitting is blocked or when the water level in the tub or spa is too high or too low.

Abstract: A generally planar antenna structure having at least six radial antenna elements, each of which uses log-periodic principles to provide a broad bandwidth of operation. Each antenna element has a radial arm and integral, arcuate teeth extending in opposite directions from the radial arm, such that the spacing, width and length of the teeth increases with increasing radial distance from the center of the structure. The teeth are preferably interleaved with teeth in adjacent antenna elements. A feed region of the structure is provided near its center, to connect the antenna elements through a connection matrix to input/output terminals and provide operation in multiple modes and multiple polarization senses.

Abstract: A combination of doubly folded parallel plate beam combiners or dividers, configured to produce a desired composite beam for use in arrays of antenna elements. The doubly folded combiner or divider functions to expand a transmitted beam, or contract a received beam, in one selected plane. In a transmit mode, a single beam can be expanded first in one direction by a first divider, then expanded in a perpendicular direction by a stack of additional dividers coupled to the first. Optional phase shifting circuits provide beam steering as desired. Second and other additional beams can be processed in the same manner, to produce a composite output of multiple beams for transmission by an antenna array. Another aspect of the invention involves the use of a beam forming structure of this type in conjunction with an array of transmit/receive microwave modules providing amplification and phase shifting functions, and an array of printed circuit antenna elements.

Abstract: A comparison circuit having at least one processing cell in which objects defined by multiple parameters are streamed from a data base through the circuit, and compared with a similarly structured object previously stored in the cell. The object stored in the cell and objects streamed through the cell are all defined by data values indicative of maximum and minimum values of the parameters making up the objects. A match is declared when all parameters of the object stored in the cell overlap the parameter ranges of the objects streamed through the cell. With the use of multiple cells connected in series or in parallel, or in a combination of series and parallel, the processing speed of the comparison circuit is increased linearly with the number of such cells. Therefore, searching of large data bases can be performed at very high speeds and configurations of interconnected processing cells can be easily interconnected and loaded to define a number of objects of interest.

Abstract: A technique for reducing the undesirable effects of amplifier offset voltages in quantizers such as analog-to-digital converters and related devices. The quantizer of the invention has an array of input amplifiers for comparing an input signal with multiple reference voltages, an array of latches for registering output signals from the amplifiers, and signal summing circuitry connected between the amplifiers and the latches, to produce a set of modified amplifier outputs for input to the latches, each of the modified amplifier outputs being derived from a weighted sum of at least three amplifier outputs. In the event of a defect in one or more amplifiers causing unwanted amplifier offsets, the summing circuitry improves linearity without the need for paralleling of transistor components. In one embodiment of the invention, the summing circuitry includes a resistor ladder to which the amplifier outputs are connected and from which the modified outputs are derived.

Abstract: Method and apparatus for the control of the rate of emission of electrons added to an ion implantation beam to neutralize charging effects on semiconductor wafers being processed. A net charging current, or equivalent voltage, is sensed continuously, but is sampled only when a selected wafer, or multiple selected wafers, are positioned to receive the entire cross section of the ion beam. The sampled charging current is used to control the addition of charge-neutralizing electrons to the ion beam, thereby eliminating problems that ensue from the use of an averaged charging current that is sensed without regard to the relative beam position or the number of wafers being processed.

Abstract: A lightweight, compliant, high strength fabric providing controlled stretch, and a process for its manufacture. The fabric is consolidated into a unitary structure from a single stacked-film matrix of one or more thin elastomeric films, each having at least one reinforcing fiber embedded in the film in a sandwich construction. The reinforcing fibers are buckled along their length when the film is in a relaxed state, and if more than one fiber, arranged in a generally parallel relationship with each other within each elastomeric film. The stacked elastomeric films are cross-plied such that the courses of fibers in the separate films are aligned in selected multiple directions, with each course of fibers lying in its own plane. Stretching of the fabric in any of the selected multiple directions is uninhibited by the buckled fibers but is limited when the fibers reach a straightened condition. As the fabric stretches, the fibers straighten, eventually limiting the stretch of the fabric as the fibers become taut.

Abstract: Apparatus, and a related method for its operation, for transmitting binary data at high speed through unshielded twisted pairs of conductors intended for a much lower data speed and bandwidth. By using a combination of demultiplexing into multiple data channels, encoding the binary signals into a modified three-level duobinary code, and filtering the signals before transmission, data rates as high as 125 megabits per second can be transmitted over four unshielded twisted pairs of conductors. Two illustrative forms of the invention are disclosed, one of which uses two channels for transmission over two twisted pairs in each direction of transmission. The other form of the invention uses four data channels, to further reduce the transmitted bandwidth in each channel, and four twisted pairs of conductors, for transmission in both directions by means of hybrid circuits interconnecting the transmitter and receiver functions at each end of the channels.

Abstract: Apparatus and a related method for detecting signal photons of a selected wavelength using ionization induced by collisions between atomic or molecular particles. Signal photons raise the energy level of a proportion of particles introduced into a detection chamber to a selected metastable state. Optionally, a pump laser assists in raising the energy level of the particles to a metastable state close to the ionization continuum. Collisions between particles in the selected metastable state and particles of the buffer gas cause ionization of the metastable particles, and a measurable electrical current is obtained, without the need for strong electric fields for ionization, or the need for strong optical fields for photoionization. In a variant form of the invention, a second substance is admitted into the detection chamber.

Abstract: A method and corresponding apparatus for providing spacecraft attitude, position and orbit data without the need for externally supplied data. Using onboard observations of the earth, sun and moon, the system determines spacecraft attitude, instantaneous position, and the orbit based on multiple position estimates. Position and orbit data are derived by multiple deterministic solutions, including some that employ star sensors and gyros, and the multiple solutions are accumulated in a Kalman filter, to provide continuous estimates of position and orbit for use when the sun or moon is not visible. The best estimate of position is selected from the multiple deterministic solutions and the Kalman filter solution, and can be used to control the spacecraft in various ways, without having to rely on ground-based equipment or other spacecraft for the determination of position and orbit.

Abstract: A memory circuit for controlling writing and reading operations in a large semiconductor memory having multiple modules, some of which are subject to production or environmentally caused defects. Memory modules are arranged in columns and there is a column interface for each column, each module being connected to its column interface by a single-bit data line. Each column interface includes a configuration register that is used to record an association between the memory modules in the column and selected data bit positions of an external data word. The same association is used both during writing operations, wherein data words are written from the data bus to the memory modules, and during reading operations, wherein data words are read from the memory modules to the data bus.

Abstract: A method and corresponding apparatus for encoding and decoding additional status bits into an existing frame status byte transmitted as part of a packet of information in a communication network. The described scheme provides for the encoding and decoding of two additional status bits, without having to modify the packet format. In the disclosed embodiment of the invention, the additional status bits are used to convey information to a node processor concerning decryption processing of a received information packets.

Abstract: A method for selective disclosure of the identity of a communication protocol under which an information packet originated, but without incorrectly identifying the protocol in a header accompanying the packet. If there is a need to conceal the identity of the underlying source protocol, a special anonymous protocol identifier is used, instead of the real protocol identifier, in the header of an encrypted information packet. Network monitors can then still provide accurate information concerning traffic on the network, without having this information distorted by the use of incorrect communication protocols. If there is a desire to reveal the underlying protocol, a subnetwork protocol frame format is used to store the protocol identity and signify whether the packet is encrypted. A packet that is of a non-subnetwork protocol can be encapsulated with a subnetwork header containing a special code signifying that there is an encapsulated packet and containing the original protocol identifier.

Abstract: A technique for resolving whole-cycle ambiguity that is inherent in phase-angle measurements of signals received from multiple satellite-based transmitters in a global positioning system. The relative position of a secondary receiving antenna with respect to a reference antenna is approximately known or approximately initially determined and then measurements from a minimum number of satellites are used to determine an initial set of potential solutions to the relative position of the secondary antenna that fall within a region of uncertainty surrounding the approximate position. Redundant measurements are taken from one or more additional satellites and used to progressively reduce the number of potential solutions to close to one. Even if the number of potential solutions is not reduced to one true solution, the number can be further reduced by using additional measurements taken at different time intervals, at which different satellite geometries prevail.

Abstract: A method and related cryptographic processing apparatus for handling information packets that are to be cryptographically processed prior to transmission onto a communication network, or that are to be locally cryptographically processed and looped back to a node processor. A special cryptographic preamble is included in each information packet that is to be subject to cryptographic processing. The cryptographic preamble contains an offset value pointing to the starting location of information that is to be processed, and completely defines the type of cryptographic processing to be performed. The cryptographic processor can then perform the processing as specified in the preamble without regard to a specific protocol. If the packet is to be transmitted onto the network, the preamble is stripped from the packet after cryptographic processing, so that the formats of packets transmitted onto the network will be unaffected by the preamble.

Abstract: A semiconductor laser array of antiguides having a large number of antiguide elements to provide relatively high optical power output with a high degree of coherence and array mode discrimination. The antiguide elements are grouped into array cells that are separated by interarray regions having a width and refractive index selected to produce a resonance condition in the 0.degree.-phase-shift array mode. Each array cell is also designed to operate in the resonant condition, and losses in the interarray regions discriminate against modes other than the 0.degree.-phase-shift mode. The entire group of cells operates as a high-power, coherent ensemble, without the degradation of mode discrimination and beam quality usually associated with large numbers of waveguide elements.