Abstract: A high precision replication system creates a nearly atomic level replica. The basic building block of the replication system is a substrate with a smooth replication surface which is to be replicated, and a graded transition layer applied to the replication surface. The graded transition layer comprises a binding material that adheres strongly to the replication surface and a release material that adheres to the replication surface with substantially less force than does the binding material. The portion of the transition layer closest to the substrate comprises predominantly the binding material, and the portion of the transition layer farthest from the substrate comprises predominantly the release material. A separation layer is applied to the transition layer, followed by a coating. The coating provides a backing to the separation layer, acting as structural support to the separation layer.

Abstract: A microwave grating 10 for a dispersive delay line, the grating comprising: (a) a terminal 12 for receiving a wideband RF signal including multiple RF signals of different frequencies; (b) a primary transmission line 14 capable of carrying the wideband RF signal, the primary transmission line 14 being electrically connected to said terminal 12; and (c) a plurality of non-resonant open-stub transmission lines 16 each having a length 18, the open-stub transmission lines 16 being capacitively loaded on the primary transmission line 14 at spaced locations 20 along the primary transmission line 14. Each open-stub transmission line 16 effects perturbations in the signal carrying capability of the primary transmission line 14 where the open-stub transmission line is located.

Abstract: A method of fabricating an electrical interconnect are provided. A first transparent dielectric layer is disposed on top of a support structure. A conductive circuit layer is plated above the first dielectric layer. Separate conductive layers are plated on top of the conductive circuit layer to produce conductive vias. A second transparent dielectric layer is disposed around the conductive layers. Contact tips are electrically connected to the top surface of the separate conductive layers. The interconnect may be visually aligned so that the contact tips brought into contact with target connections. In addition, the support structure may be partially removed to allow a flexible interconnect.

Abstract: A radar system (10) uses independent, adaptive modulation controls for the local oscillators (16, 40) in the transmitter (24) and receiver (26) portions. The adaptive modulation enables the radar to filter out any repeater jammer signal while maintaining a good signal-to-noise ratio (SNR) on the target. The radar system (10) provides a SNR that is sensitive to the target range and minimizes the SNR at the jammer range and maximizes the SNR at the target range. A communication system (60) similarly uses independent, adaptive modulation controls (66, 84) to provide a communication system resistant to jamming.

Abstract: A high temperature superconductor junction and a method of forming the junction are disclosed. The junction 40 comprises a first high-T.sub.c, superconductive layer (first base electrode layer) 46 on a substrate 42 and a dielectric layer 48 on the first high-T.sub.c, superconductive layer. The dielectric layer and the first high-T.sub.c superconductive layer define a ramp edge 50. A trilayer SNS structure 52 is disposed on the ramp edge to form an SSNS junction. The SNS structure comprises a second high-T.sub.c, superconductive layer (second base electrode layer) 54 directly on the first high-T.sub.c superconductive layer, a normal barrier layer 56 on the second high-T.sub.c superconductive layer, and a third high-T.sub.c superconductive layer 58 (counterelectrode) on the barrier layer. The ramp edge is typically formed by photoresist masking and ionmilling. A plasma etch step can be performed in-situ to remove the photoresist layer 62 following formation of the ramp edge.

Abstract: Both recursive and non-recursive fiber-optic loop elements are cascaded to form various fiber-optic lattice configurations to form a fiber-optic signal processor for use in wideband applications capable of processing radio frequency (RF) signals. Each fiber-optic loop element includes a fiber-optic element, such as a monomode optical fiber or a monomode optical waveguide formed in a loop by way of a fiber-optic coupling device and one or more reflection mechanisms, such as a Bragg grating. In order to provide increased flexibility, the present invention allows the reflectivities of the reflection elements to be selected to provide additional flexibility in creating the frequency response characteristics of an optical signal processor.

Abstract: A heterojunction bipolar transistor and a method for fabricating an HBT with self-aligned base metal contacts using a double photoresist, which requires fewer process steps than known methods, while minimizing damage to the active emitter contact region. In particular, a photoresist is used to form the emitter mesa. The emitter mesa photoresist is left on and a double polymethylmethacrylate (PMMA) and photoresist layer is then applied. The triple photoresist combination is patterned to create a non-critical lateral alignment for the base metal contacts to the emitter mesa, which permits selective base ohmic metal deposition and lift-off. By utilizing the double photoresist as opposed to a metal or dielectric for masking, an additional photolithography step and etching step is eliminated. By eliminating the need for an additional etching step, active regions of the semiconductors are prevented from being exposed to the etching step and possibly damaged.

Abstract: A modulated clock MSK modulator that separately modulates a sinusoidal clock signal by square wave I and Q digital data signals prior to the I and Q data signals being modulated onto a carrier wave signal. Mixers or applicable biphase switches are utilized to impress the I and Q digital data signal information onto the clock signal by inverting or non-inverting the clock signal on separate I and Q data rails to create I and Q modulated clock signals separated in phase. The I channel data modulated clock signal and the Q channel data modulated clock signal are then separately applied to a conventional quadraphase modulator to be separately modulated onto a carrier wave signal, and the summed together to be transmitted.

Abstract: A satellite based telecommunications system having a multiple registration location register which enables a terminal to register with more than one earth station simultaneously, without any particular one of the earth stations knowing that the terminal is registered elsewhere. The multiple registration location register receives the registration information from each of the earth stations and records the information. This information is used by the multiple registration location register to re-route calls to an earth station that is providing coverage for the terminal. The multiple registration location register may consider many system factors, including satellite to earth station connectivity and satellite to terminal connectivity, in determining to which earth station it should route calls.

Abstract: A radiometric data acquisition and display system is provided. The system has a detector assembly with a boom. A radiometer is connected at an end of the boom. The radiometer has a sensor head including an antenna horn to acquire radiometric data from an area of interest. A rangefinder is constructed and arranged to provide location data indicative of a position of the sensor head, and a data processor is connected to receive the location data from the rangefinder and the radiometric data from the radiometer. The data processor includes signal processing circuitry and a display connected to the computer. A method of acquiring and displaying a radiometric image of an object is also provided.

Abstract: A technique for correcting wavefront aberrations introduced by large primary optical elements in portions of the electromagnetic spectrum. The aberrations of the primary element are first transferred to a beacon beam and this aberrated beam is interfered with a reference beam in a holographic medium. These beams are then turned off and a beam from a distant object, containing the same aberrations, is allowed to diffract from the hologram. The diffracted beam from the hologram contains the image of the distant object with aberrations removed. Use of this technique permits the construction of large optical elements inexpensively, since surface tolerances of the elements can be substantially relaxed.

Abstract: Passenger restraint system including a crash sensor for deploying an air bag associated with a vehicle during a crash event. The crash sensor includes a low frequency accelerometer circuit and a high frequency pressure transducer circuit. The low frequency accelerometer circuit senses low frequency signals from the deceleration of the vehicle as a result of the crash event, and the high frequency transducer circuit senses high frequency signals from the deformation of metal components as a result of the crash event. The combination of the high frequency signals and the low frequency signals provides an accurate indication for deployment of the air bag.

Abstract: There is provided a cylindrical valve 20 for placement in the flow path of a singlet-delta oxygen generator 12 that feeds O.sub.2.sup.* to a chemical laser gain medium 14. The feed path 22 includes a sharp 90.degree. bend 24 that causes fluid velocity variations in O.sub.2.sup.* entering the gain medium 14. Integral with the valve 20 is a tubular structure 12 having a partial circumferential radially extending surface 44 fitted with "O" ring for sealing and opening the feed path between the "O.sub.2.sup.* " generator 12 and gain generator 14. A series of vanes 32, 34, 36 disposed in velocity control zones 50, 52, 54 and 56 are integral with the valve 20 for leveling out the velocity variations and controlling the wake formation 58, 59 and 60 in the O.sub.2.sup.* entering the gain generator 14.

Abstract: An optic cell 20 for use in the cavity of a high-power laser comprises an optic housing 22 which defines a first laser beam aperture 26. An optic element 32 such as a mirror or lens is disposed within the optic housing. A first indium layer 30 is between and in abutting contact with the optic housing and the optic element. An optic cover 40 defines a second laser beam aperture 46 therethrough substantially in alignment with the first laser beam aperture to form a window 47 of the optic element through which a laser beam passes. A second indium layer 48 is between and in abutting contact with the optic element and the optic cover. The optic housing and the optic cover are typically formed of aluminum or copper to passively cool the optic element.

Abstract: An antenna and antenna feed assembly for a communication handset is constructed as a unitary assembly in which each of the antenna and antenna feed, suitably a balun, conform to a cylindrical geometry and is small enough in size for handset applications.

Abstract: A multi-state Josephson memory in a superconductor integrated circuit includes a plurality of superconductive quantum interference device (SQUID) memory cells 2 each having a SQUID 4 characterized by a SQUID loop inductance L and a junction critical current I.sub.c, which determine the number of memory states that can be stored in the SQUID 4. A gate current I.sub.g is transmitted to the superconductive inductors 6 and 8 of the SQUID 4 to perform a read operation by crossing a designated number of current threshold boundaries corresponding to the memory state stored in the SQUID, so that the Josephson junction 12 of the SQUID 4 generates a number of pulses corresponding to the memory state. A control current I.sub.con writes data to the SQUID 4 through a control current input 16, and is preferably magnetically coupled to the SQUID 4 through superconductive inductor pairs 18, 6 and 20, 8. In a preferred embodiment, a plurality of SQUID memory cells 70a, 70b, . . .

Abstract: A gain generator 10 for use in high-energy flowing gas lasers such as COIL devices comprises a chemical reactant mixing nozzle 12 disposed in a gain medium 16. The nozzle includes a plurality of blades 22 formed of a plastic material resistant to chemical attack at the operating temperature of the gain medium and non-catalytic to O.sub.2 (.sup.1 .DELTA.). A preferred material is polyetherimide. The gain medium includes octagonal shaped openings 50 for the optical mode of the laser beam.

Abstract: A splitterless optical broadcast switch (110) for routing a plurality of optical carrier signals. The splitterless optical broadcast switch (110) includes an optical source (112) for generating a plurality of unmodulated optical carrier signals. A first stage routing module (114) routes the plurality of unmodulated optical carrier signals. A modulating module (116) receives a plurality of RF input signals and modulates each of the RF input signals onto any number of the unmodulated optical carrier signals to generate a plurality of modulated optical carrier signals. A second stage routing module (118) routes the plurality of modulated optical carrier signals complimentary to the first stage routing module (114). An output module (120) receives the plurality of modulated optical carrier signals such that the optical output from the optical source (112) is paired to a complimentary optical input of the output module (120).

Abstract: A steerable feeder link antenna is formed of a steerable reflector and a stationary feed horn assembly. A novel feed horn assembly allows dual mode transmit and receive functions for circularly polarized microwaves. The feed horn assembly includes a four arm turnstile junction coupled to a feed horn through the feed horn's side wall to couple transmit frequencies and an axially coupled transmission line for the receive frequencies. Each turnstile junction arm incorporates chokes for the receive frequencies. The transmission line's cut off frequency is above the transmit frequency to prevent transmit signals from interfering with receive signal receivers.

Abstract: A satellite-based cellular telecommunications system employing a constellation of telecommunications satellites in medium earth orbit to provide multibeam radio frequency (rf) communications links for worldwide cellular telephone service with a minimum number of satellites. The telecommunications satellites are placed in a plurality of inclined orbits about the earth at an altitude of between approximately 5600 and 10,000 nautical miles. The characteristics of the orbits, such as the number of orbits, the inclination of each orbit, the number of satellites in each orbit and the altitude of the satellites, are tailored to maximize the coverage area of the satellites and their related line-of-sight elevation angles, while minimizing propagation time delays, the number of beam-to-beam and satellite-to-satellites handovers, and the total number of satellites.