Abstract: An integrated circuit device includes a thin semiconductor layer disposed on a surface of a wafer, a plurality of wafer-scale integrated (WSI) circuits formed on the semiconductor layer, and a node formed on the semiconductor layer that provides an optoelectronic interface to an axial optical data bus for high-speed optical interconnectivity between the WSI circuits and other external devices interconnected to the optical data bus.

Abstract: A HEMT device comprises a buffer layer disposed over a substrate. A partially-relaxed channel is disposed over the buffer layer and a barrier layer is disposed over the channel. A cap layer is disposed over the barrier layer and a gate is positioned on the barrier layer. A source and a drain are positioned on the barrier layer on opposite sides of the gate.

Abstract: A multi-pattern reflector antenna for generating first and second antenna patterns from first and second RF signals having first and second frequencies of operation respectively. The antenna includes a reflector having a focal point, first and second subreflectors configured to image the focal point at first and second preselected locations respectively; and, first and second feeds positioned at the first and second preselected locations. The first and second feeds are configured to operate at the first and second frequencies of operation respectively and are operative to generate first and second radiated RF signals from the first and second RF signals respectively. The first and second subreflectors partially overlap each other with the first subreflector configured to be a frequency selective structure which reflects RF signals having the first frequency of operation and passes RF signals having the second frequency of operation.

Abstract: A HEMT device comprises a buffer layer disposed over a substrate. A partially-relaxed channel is disposed over the buffer layer and a barrier layer is disposed over the channel. A cap layer is disposed over the barrier layer and a gate is positioned on the barrier layer. A source and a drain are positioned on the barrier layer on opposite sides of the gate.

Abstract: A method for transferring a data packet between a first source terminal and a first destination terminal, in a communications network having a plurality of source terminals, destination terminals, satellites and downlink antenna beams one downlink antenna beam of which covers the first destination terminal. Each data packet includes a destination address identifying a user for which the data packet is meant with the first destination terminal having the capability to reach the user. The method includes assigning a unique downlink beam identifier to each the downlink antenna beam in the communications network; mapping the destination address to a downlink beam identifier, the corresponding antenna beam of which covers the first destination terminal. The data packet is segmented into one or more cells, each cell having a cell header. The downlink beam identifier is placed into each cell header and the cells are routed to the downlink antenna beam corresponding to the downlink beam identifier.

Abstract: A method and apparatus for the inspection of a substrate provides consistent detection of defects such as cracks, differentiates between different types of defects, and, does not excessively heat the substrate. An infrared radiating source produces infrared energy which illuminates the substrate in a uniform manner at an incident angle. An infrared camera collects a portion of the infrared light which is reflected from the substrate. An image is created from the collected light which includes indicia of the defect. The image is examined as the incident angle is varied for changes in the appearance of the indicia.

Abstract: A fully optical converter for converting an analog signal into a digital signal includes an amplitude to optical wavelength converter for converting the analog signal into an optical signal which varies in wavelength in accordance with an amplitude of the analog signal, a splitter for applying the optical signal over a desired number of light paths, an interferometer connected to each of the light paths, unequal path lengths in each leg of the interferometers to allow optical interference to deliver a complementary sinusoidal transfer function to the optical signal to generate two complimentary output signals and a dual detector connected to each of the interferometers for generating a digital bit in response to the two complimentary output signals, wherein each of the digital bits together form a parallel digital word. The fully optically based converter is automatic and independent of interactive techniques, thus providing for an expedited conversion rate.

Abstract: A method for determining the susceptibility of solar cell cover glass or second surface mirror to ultraviolet (UV) degradation comprises the steps of illuminating the solar cell cover glass with ultra violet light at a preselected illumination angle where the solar cell cover glass reflects a portion of the ultraviolet light; measuring the reflected portion of the ultraviolet light; and, characterizing the propensity of the cover glass or contaminate layer on a second surface mirror to degradation as a function of the reflectance. The process results in an improvement of the long-term power output of solar cells by screening out cover glasses that have a propensity to darken under solar-equivalent UV exposure and thus maintaining optical transparency arising from increased solar absorption in darkened cover glass. The process will additionally result in decreased contaminant levels on thermal control surfaces and less on-orbit degradation.

Abstract: A steerable antenna comprises a steerable main reflector and a stationary feed assembly and subreflector assembly configured in a side-fed configuration where the feed assembly is to a side of both the main reflector and the subreflector. The main reflector, subreflector and feed assembly together produce an antenna beam which is directed in a preselected direction by the main reflector. A gimbal is coupled to the main reflector for positioning the main reflector and scanning the antenna beam over a preselected coverage area while the feed assembly and subreflector remain substantially stationary.

Abstract: An implant patterned superconductive device and a method for indirect implant-patterning of oxide superconducting materials is provided. The method forms a device having an oxide superconducting layer on a substrate, deposits a passivation layer atop the oxide superconducting layer, and implants chemical impurities in a selected portion of the superconducting layer through the passivation layer. This modifies the conductivity of the selected portion of the oxide superconducting layer and electrically isolates the selected portion from the non-selected portion of the oxide superconducting layer. The passivation layer is made of a material less susceptible to implant damage than the oxide superconducting layer to allow inhibition of the oxide superconducting layer while protecting the crystalline structure of the top surface of the oxide superconducting layer and keeping it planarized.

Abstract: A spacecraft having a movable structure which is held in a preselected location by a holding mechanism substantially free of microdynamic noise. The holding mechanism comprises two mechanical members in physical contact with each other and movable with respect to each other. The unintentional movement of the two mechanical members with respect to each other generates microdynamic noise. The two mechanical members are secured together to provide joinder of the two mechanical members when the movable structure is located in the preselected position to prevent long-term unintentional movement between the two mechanical members.

Abstract: An apparatus for determining the pointing uncertainty of a satellite communications system comprises a communications terminal coupled to a pointing mechanism which is operative to move and position the communications mechanism. A data storage device is configured to store data from which an actual position of a preselected light source which radiates a reference light can be determined. An acquisition sensor is positioned to move with the communications terminal and is configured to focus incident light onto the acquisition sensor. A control mechanism is coupled to the pointing mechanism and is operative to move the pointing mechanism to a position which would focus the reference light source at a preselected position on the acquisition sensor if the pointing uncertainty were substantially zero. The reference light focusing at a measured position on the acquisition sensor.

Abstract: The invention is an airframe which includes a vehicle (12) having a solid propellant rocket engine (14) and a ramjet or scramjet engine (16); a thrust plug (18) extending from an end (20) of the vehicle which directs combustion gases (23 and 64) produced by the solid propellant rocket engine or ramjet/scramjet engine to produce forward thrust; a longitudinal passage (38) extending from the end of the vehicle to an opening (30) forward of the end which receives external air directed by forward movement of the vehicle and in which solid propellant (32) of the solid propellant rocket engine is located, and wherein during rocket operation solid propellant is combusted to produce the combustion gases in the longitudinal passage which are conveyed by the longitudinal passage into contact with the thrust plug and during ramjet/scramjet operation the longitudinal passage is open to flow of external air after operation of the solid propellant rocket engine is completed and which supports mixing and combustion of the a

Abstract: A method for transferring a data message, in a connectionless manner between a selected source terminal and a selected destination terminal, in a communications network which supports connection-oriented communications. The network has a plurality of source and destination terminals in addition to satellites having up and downlink antenna beams. One of the uplink beams covers the selected source terminal and one of the downlink antenna beams covers the selected destination terminal. Downlink beam identifiers are assigned to each downlink antenna beam in the network. An address is assigned to each destination terminal so that the address of the selected destination terminal includes a downlink beam identifier of one downlink antenna beam in the network which covers the selected destination terminal. The downlink beam identifier is used to route the data message through the network.

Abstract: An adjustable surface acoustic wave (SAW) transducer is fabricated on a piezoelectric substrate. The adjustable SAW transducer includes a plurality of SAW interdigital transducer (IDT) fingers disposed on the substrate. Miniature switches are used to provide a plurality of interconnection patterns between the SAW IDT fingers such that a plurality of SAW characteristics can be generated from a single set of SAW IDT fingers.

Abstract: An umbrella-shaped matching network (10, 14, 16) for matching phase and impedance in a power amplifier (2). The matching network (10, 14, 16) employs rounded corners (22). The rounded corners (22) reduce microwave signal scattering losses, because they are less prone to signal radiation than square corner power combining networks. The matching network (10, 14, 16) includes slits (24) defining separated arms (26). The slits (24) are positioned in such a way that they provide phase and amplitude balance for the signal presented to the amplifiers (2). The slits (24) also prevent current from traveling transversely.

Abstract: A method for etching GaN material comprising configuring the GaN material as an anode in an electrochemical cell where the electrochemical cell is comprised of an anode, a cathode and an electrolyte, and applying a bias across the anode and the cathode to a level which is sufficient to induce etching of the material. The etch rate of the material is controllable by varying the bias level. The cell is additionally illuminated with a preselected level of UV light which provides for uniformity of the etching process. The present method is particularly useful for etching a GaN HBT from n-p-n GaN material.

Abstract: An antenna for providing a first antenna pattern at a first frequency of operation and a second antenna pattern at a second frequency of operation from first and second RF signals, respectively. The antenna included a horn which is dimensioned to generate the first antenna pattern from the first RF signal. A conduit is located within the horn and is configured to propagate the second RF signal in a waveguide mode. A corrugated rod having a first and a second portion is associated with the conduit. The first portion of the rod is located inside the conduit and the second portion of the rod protrudes from the conduit into the horn. The rod is configured to be responsive to the second RF signal and is operative to transition the second RF signal from a waveguide mode to a surface wave mode and propagate the second RF signal in a surface wave mode along the rod. The rod is configured to generate a second antenna from the second RF signal propagating in a surface wave mode.

Abstract: A satellite communication system which performs switching on data cells. A switch (80) receives the data cells at a set of input ports (IP1-IP128) and directs them to a set of output ports (OP1-OP128). In order to arbitrate input data cells contending for the same output port, decision factor codes and routing codes are serially conducted to input registers (210), and a pseudo-random sequence code is appended. The combined codes are ordered by routing code in a decoder (220). The code with the highest decision factor code is selected in one or more determinators (230 and 240). The selected code is identified by a bit in a result register (250).

Abstract: An antenna system comprising a feed array, a subreflector and a main reflector which are oriented to define a offset gregorian antenna geometry. The feed array is comprised of a plurality of separate feeds which are aligned on a predetermined contour. Each feed array is coupled to a feed network which acts to combine the illumination beams of clusters of a preselected number of feeds to produce a plurality of composite illumination beams. Each composite illumination beam is directed to be incident upon a separate predetermined location on the subreflector which directs the composite illumination beams and directed towards the main reflector. Each composite illumination beam is reflected by the main reflector in a preselected direction so that each composite illumination beam forms an antenna beam that impinges a predetermined coverage area on the Earth.