Abstract: A coordinatable system of geosynchronous ("24 hour"), inclined, and slightly elliptic satellite orbits, increases available satellite orbital capacity and enables spectrum re-use by forming "highways" of moving "slots" in the space in and about the geostationary orbit (GSO) belt worldwide. Each of a plurality of repeating ground tracks is shared by multiple satellite orbits (and thus "slots"), positioned to achieve specified minimum specified angular separation from other slots using the same frequencies. Ground tracks are located at specified longitudes of symmetry, and orbital parameters are chosen to realize certain which provide the near-maximum total number of slots and which fit neatly within, and replace, some of the existing grid of GSO slots. Incremental modularity permits gradual expansion from current GSO usage, while systematic extension results in large theoretical capacity expansion.

Abstract: A satellite-based communications system operating at high data rates includes a plurality of communications satellites each having an uplink and a downlink antenna for receiving and transmitting a plurality of spot beams corresponding to a plurality of coverage areas at a plurality of frequencies. The system further includes a plurality of dedicated communications links between a source location in one of the plurality of coverage areas and a destination location in another one of the plurality of coverage areas wherein the plurality of dedicated communications links are each assigned an exclusive time interval for transmitting and receiving communications signals to and from each of the plurality of satellites. The plurality of satellites each have an uplink and downlink antenna beam switch coupled to the uplink and downlink antennas for selecting a reconfigurable subset of the plurality of spot beams based on the time interval.

Abstract: A traveling wave tube incorporates a collector having a plurality of collector electrodes, one or more of which is operated at a potential below that of the cathode so as to collect electrons having associated energies greater than the cathode potential (E.sub.K), and thereby act as a high impedance current source. The current from the collector electrode operated below the cathode potential (E.sub.K) is converted by a power converter to an alternating current signal that can be either magnetically coupled to the high voltage transformer (T.sub.1) of the traveling wave tube power supply, or coupled to an external load with a transformer (T.sub.2), thereby improving the operating efficiency of the traveling wave tube system.

Abstract: A method of preparing Li.sub.x Mn.sub.2 O.sub.4 for a secondary battery includes mixing lithium nitrate, magnanese nitrate and citric acid. A complex citrate solution is formed in the substantial absence of a polyhydroxyl alcohol. The complex citrate solution is dehydrated to produce a precursor. The precursor is then heated at a substantially constant rate and then calcined to provide a spinel compound.

Abstract: Various structures for cantilever beam tunneling rate gyro devices formed on a single substrate are disclosed. A cantilever electrode having a plurality of portions extending from the substrate with one end of the cantilever is suspended above the substrate at a distance from a tunneling electrode so that a tunneling current flows through the cantilever and tunneling electrode in response to an applied bias voltage. The cantilever and tunneling electrodes form a circuit that produces an output signal. A force applied to the sensor urges the cantilever electrode to deflect relative to the tunneling electrode to modulate the output signal. The output signal is a control voltage that is applied between the cantilever electrode and a control electrode to maintain a constant tunneling current. In the preferred embodiment, two cantilever portions extend from the wafer surface forming a Y-shape. In a further embodiment, a strap is fabricated on the cantilever electrode.

Abstract: An message handling system for handling the delivery of critical and time critical messages for a near-real-time or real-time simulation environment. A message delivery type (38) accompanies each message (34) to designate whether the message (34) is delivery critical (46) or time critical (42). A message receiver (50) receives the message (34). A message delivery selector (58) selects a protocol based on the message delivery type (38) as determined by a message type determinator (54). The selected protocol conforms to a message format which has a common header and a message component. The message (34) is then sent to the intended recipient computer via the selected protocol.

Abstract: A collector for collecting an electron beam in a traveling wave tube is disclosed. The collector has an input end for receiving the electron beam from the traveling wave tube. The collector also has a plurality of stages biased at given voltages and arranged along a common collector axis and positioned at a different axial position with respect to the input end. A stage is biased more negatively with a voltage than a successive stage positioned axially farther from the input end to generate an electrostatic focusing lens for focusing the electron beam toward successive stages thereby increasing the collection efficiency of the collector.

Abstract: A multiband millimeterwave antenna system for communicating signals in multiple frequency bands is disclosed. A main antenna body is connected to antenna extensions by micro-electro-mechanical switches. By opening and closing the switches, the length of the antenna can be altered. The antenna is coupled to a microstrip feed line by an aperture. A series of matching stubs match the impedance of the feed line for the various signal frequencies.

Abstract: A highly uniform, planar and high speed JHEMT-HBT MMIC is fabricated using a single growth process. A multi-layer structure including a composite emitter-channel layer, a base-gate layer and a collector layer is grown on a substrate. The composite emitter-channel layer includes a sub-emitter/channel layer that reduces the access resistance to the HBT's emitter and the JHEMT's channel, thereby improving the HBT's high frequency performance and increasing the JHEMT's current gain. The multi-layer structure is then patterned and metallized to form an HBT collector contact, planar HBT base and JHEMT gate contacts, and planar HBT emitter and JHEMT source and drain contacts.

Abstract: An integrated digital circuit is protected from reverse engineering by fabricating all transistors of like conductivity with a common size and geometric layout, providing a common layout for different logic cells, connecting doped circuit elements of like conductivity with electrically conductive doped implants in the substrate rather than metalized interconnections, and providing non-functional apparent interconnections that are interrupted by non-discernable channel stops so that all cells falsely appear to have a common interconnection scheme. The camouflage is enhanced by providing a uniform pattern of metal leads over the transistor array, with a uniform pattern of heavily doped implant taps from the transistors for connection to the leads; undesired tap-lead connections are blocked by channel stops.

Abstract: A self-biasing element is formed by coupling an electron accumulator to a collector stage of a linear-beam microwave tube with a base which has a selected resistance. The electron accumulator has a secondary emission coefficient less than one and is positioned to intercept a portion of the electrons in the electron beam of the linear-beam microwave tube. The electron accumulator thus acquires a negative voltage whose magnitude is controlled by selecting the base resistance and the radial and axial position of the self-biasing element within the collector. Various arrangements of self-biasing elements and collector stages are disclosed which improve the efficiency and RF performance of the microwave tube.

Abstract: Apparatus compensating for gain variations versus frequency of a traveling wave tube (TWT) is disclosed. The apparatus provides an RF interaction circuit section designed with specified mismatches causing internal reflections of the RF waves, such that the overall gain response is flattened out or inverted.

Abstract: An integrated-circuit interconnect which can be formed at the wafer level is achieved by depositing an intentionally stressed contact layer over a release layer which is subsequently removed. The removal of the release layer permits a portion of the contact layer to curve away from the surface of an integrated circuit chip. The result is a spring contact having a base portion joined to a metal member of the chip and a spring portion which is available for joining to other metal members, e.g., on a substrate or another chip. The resilience of the spring portion can also be used to position and align integrated circuit elements.

Abstract: An integrated-circuit interconnect which can be formed at the wafer level is achieved by depositing an intentionally stressed contact layer over a release layer which is subsequently removed. The removal of the release layer permits a portion of the contact layer to curve away from the surface of an integrated chip. The result is a spring contact having a base portion joined to a member of the chip and a spring portion which is available for joining of other metal members, e.g., on a substrate or another chip. The resilience of the spring portion can also be used to position and align integrated circuit elements.

Abstract: A corona source suitable for use in vehicle ignition systems uses a conductive coil that receives an RF input at one end and has a corona discharge site at the other end, with a reference electrode capacitively coupled to the coil. The pitch and the length of the coil are selected to produce a corona discharge in response to an RF input signal at a predetermined frequency and voltage, through quarter wavelength resonation. Either the new resonant coil or other corona discharge devices can be used to remediate fluid-borne wastes by initiating and sustaining RF corona discharges within the fluid. The pulses used to initiate the corona discharge preferably have alternating positive and negative components, with high initial voltages on the positive components to initiate the discharge, followed by lower positive voltage levels to sustain the discharge. Unipolar pulses, preferably with progressively decreasing voltage levels, can also be used.

Abstract: A focal-plane detector imaging system that can tolerate higher intensity optical beams than prior systems, without a reduction in the system's field-of-view, comprises an imaging lens, a fiber optic array positioned at the image plane of the imaging lens and an image detector positioned at the output end of the fiber optic array. The optical fibers that make up the fiber array have core diameters that are larger than the focal spot of an incoming optical beam. In operation, the fiber array transfers the imaged scene to the image detector at its output end. The focused optical beam is also transferred to the image detector at the array's output end, but its diameter is enlarged due to its angular divergence. In a preferred embodiment, the f-number of the imaging lens, diameter of the fiber cores, and the lengths of the fibers in the array are designed so that, as the power of an incoming optical beam increases, the optical damage threshold of the fiber array is reached before that of the image detector.

Abstract: Base contacts are made to one or both barrier layers of a resonant tunneling bipolar transistor, rather than to the quantum well. This is made possible with the use of a type II rather than a type I energy band alignment in the active region.

Abstract: In a parallel processing architecture following the Single Instruction stream Multiple Data stream execution paradigm where a controller element is connected to at least one processing element with a local memory having a local memory address shift register adapted to receive and retain therein a globally broadcast memory base register address value received from the controller element for use by the processing element for access and transfer of data between the processing element and its respective local memory, a computer architecture for implementing indirect addressing and look-up tables includes a processing element shift register associated with the at least one processing element and adapted to receive and retain therein a local memory offset address value calculated or loaded by the associated processing element in accord with a first predetermined set of instructions.

Abstract: Contaminants are cleaned from the surface of a body in space by generating a substantially space-charge neutral reactive plasma, directing the plasma onto the contaminated surface at an energy below the surface sputtering energy (typically 20 eV), and reacting the plasma with the contaminants to remove them. A helicon wave plasma source is made light weight and compact enough for spacecraft use, with a plasma energy low enough to avoid damaging optical surfaces, by using permanent magnets to establish a static axial magnetic field, and a simple but novel rf antenna design. The antenna consists of a pair of spaced conductive rings which extend around the plasma tube, with conductive base and rf feed bars extending between the rings on diametrically opposite sides. The feed bar is interrupted to provide an rf input on opposite sides of the interruption. The antenna is preferably formed as an integral metal unit, with its rings rigidly supported by and integral with opposite ends of the base bar.

Abstract: A broaching tool has a plurality of cutting teeth for broaching a small, deep hole with high precision and surface finish. Three to eight teeth are engaged in the hole for cutting at any one time. For broaching sticky metals such as stainless steel, each cutting tooth has a face angle, backoff angle and rise which are sufficiently large to prevent thermal hardening of the hole surface. A ring is provided between the front face and land of each cutting tooth having a width selected to prevent formation of axial and ring-shaped tool traces. V-shaped notches having a large radial angle and a small backoff angle are formed in the land of each cutting tooth to break chips and prevent clogging. The tool further includes a rear pilot having a plurality of smoothing teeth with a diameter larger than the finished diameter of the hole. A set of rough and fine broaching tools can be provided, with the fine tool being processed to convert it to a rough tool when it is worn beyond tolerance.