Abstract: A process for designing spacecraft structural elements (20, 30) that increases spacecraft structure intrinsic damping to relax stiffness design constraints that are necessary for precision pointing requirements. The process includes specifically designing the spacecraft structural elements (20, 30) to have a stiffness that is intrinsically not suitable to meet mission pointing performance requirements in order to reduce weight and volume. To overcome this deficiency, the structural elements (20, 30) are equipped with strain energy control elements (44) that sense strain in the structural elements (20, 30) from on-board and external disturbances, and provide actuation of the structural elements (20, 30) to counteract the sensed strain. The strain energy control elements (44) can be any suitable control element that senses strain and actuates the structural element (20, 30), such as piezoelectric electric or electrostrictive control elements.

Abstract: A receiver (10) for a wireless telecommunications system that provides relatively wideband signal processing of received signals without increased signal distortion so that multiple received signals can be simultaneously processed. The receiver (10) includes a specialized LNA (16), frequency down-converter (18) and ADC (20) to perform the wideband signal processing while maintaining receiver performance. The frequency down-converter (18) employs a suitable mixer (28), BPA (32), attenuator (34), and transformer (36) that are tuned to provide the desired frequency down-conversion and amplitude control over the desired wideband. The down-converter devices are selected depending on the particular performance criteria of the ADC (20). A specialized digital channelizer (22) is included in the receiver (10) that receives the digital signal from the ADC (20), and separates the signals into the multiple channels.

Abstract: A roller squeegee and spinner adapter tool is disclosed for safely, easily, speedily and thoroughly removing paint or other coating material from a roller by squeegeeing or sliding the major bulk of paint from the roller and then attaching a mini-roller to a paintbrush and roller spinner for conveniently removing residual paint and cleaning solution from the mini-roller via the spinning action (centrifugal force) of the spinner.

Abstract: A system for air-ground (120) and air-air (122) communications wherein a VHF data radio (204) is coupled to a high-speed bus (304). The VHF data radio complies with the ARINC 716/750 standard and is accessible via the bus using a programmable interface (306). A communications management unit (208) can also be coupled to the high-speed bus, which communicates with the VHF data radio via the bus according to the programmable interface.

Abstract: A switched gain circuit (350) that employs a plurality of conduction paths (378-384) that provide different levels of signal gain or attenuation to an analog input signal. Each conduction path (378-384) includes a plurality of switching devices (388-402 and 410-424), such as heterojunction bipolar transistors. Further, each conduction path includes a gain device such as a degenerative resistor, that provides gain or attenuation to the analog input signals. A separate control signal is applied to a switching device (410-424) in each conduction path (378-384) to select a particular conduction path to be coupled to the output. The analog input signal can be a differential analog input signal where a first part of the signal is coupled to the base terminal of a bipolar transistor (410-424) in each conduction path (378-384), and a second part of the analog signal is coupled to the base terminal of another bipolar transistor (410-424) in each conduction path (378-384).

Abstract: A multifunction millimeter-wave system (10) that provides simultaneous and prioritized active radar protection and surveillance, high digital data rate communications, interceptor missile guidance, passive surveillance and IFF interrogation for a military vehicle. The system (10) includes a multi-function control computer (14) that provides high level control functions. The system (10) also includes a plurality of azimuth sector sub-systems (12), each including a steerable antenna (26) that directs a millimeter-wave beam to a particular location within the area covered by the sector sub-system (12). Each sector sub-system (12) also includes an FPGA-based modem (20) that performs digital signal processing for the various system operations, such as signal modulation and demodulation. Each sector sub-system (12) also includes an IF/RF transceiver (22), including a direct digital synthesizer (24), for providing signal tuning and frequency up-conversion and down-conversion.

Abstract: A lumped element ring balun (60) including elements patterned on a monolithic substrate (62) in a compact design. The balun (60) includes four inductors (64, 66, 68, 70) and a plurality of capacitors (190, 192, 198, 202, 214, 226) electrically coupled together to provide RF output signals that are 180° out of phase with each other. The inductors (64-70) are symmetrically disposed in a rectangular area on the substrate (62). A first pair of the inductors (64, 66) is positioned at one end of the rectangular area, and a second pair of the inductors (68, 70) is positioned at opposite end of the rectangular area. All of the capacitors are formed on the substrate (62) in a central circuit area (72) between the first pair of inductors (64, 66) and the second pair of inductors (68, 70). Inner ends (76, 92, 98, 106) are coupled to circuit elements in the circuit area (72) by a metallized trace (120, 136, 150, 170) extending through an air bridge (124, 140, 154, 174).

Abstract: A foldable table for use as a computer system workstation. The table includes an enclosure having opposing top and bottom panels, opposing front and back flanges and opposing end panels. A first rear leg is pivotally coupled to the top panel adjacent one end panel and a second rear leg is pivotally coupled to an opposite end of the top panel adjacent the other end panel. Both rear legs include a channel defined by opposing side walls. A first top support arm and a first front leg are pivotally coupled to the first rear leg, and a second top support arm and a second front leg are pivotally coupled to the second rear leg proximate the top panel. The first support arm and the first front leg are partially stored within the channel in the first rear leg, and the second support arm and the second front leg are partially stored within the channel in the second rear leg. An electrical outlet strip is rigidly mounted to an inside surface of the bottom panel.

Abstract: A combined multiplexer and switched gain circuit (250) that selectively multiplexes differential analog signals from a primary channel (20) and a diversity channel (22) in a diversity receiver system (10) to a single output. The circuit (250) is based on a current mode logic design where a plurality of separate conduction paths (278-284) are provided between a voltage line (266) and a current source (268). An output line (264) of the circuit (250) is coupled to each conduction path (278-284) so that the differential analog signals from the primary channel (20) and the diversity channel (22) can be selectively outputted to the circuit (250). Each conduction path (278-284) includes a gain device, such as degenerative resistor, that provides signal gain or no signal gain for that conduction path (278-284). Control signals are selectively applied to switching devices (310-324) and each conduction path (278-284) so that the conduction path (278-284) can be independently selected to provide the multiplexing.

Abstract: A differential PIN diode attenuator (450) that selectively attenuates a differential analog input signal. The two parts of the differential signal are applied to separate input lines (452, 454) and are 180° out of phase with each other. One input line (452) is coupled to a first attenuation path (456) including a resistor and a first non-attenuation path (458) including a PIN diode (462). The other input line (454) is coupled to a second attenuation path (466) including a resistor and a second non-attenuation path (468) including a PIN diode (472). The diodes (462, 472) are biased by a DC bias signal so that the differential analog signal can bypass the attenuation paths (456, 466). The DC bias signal is applied halfway between the input lines (452, 454) where the two parts of the differential signal cancel. A shunt diode (490, 492,) and parallel shunt resistors are provided in combination with the attenuation resistor to allow it to have a relatively small value.

Abstract: A multifunction printed antenna for wireless and telematic applications. In one embodiment, GPS and satellite radio patch antenna elements are printed on one side of a printed circuit board and AMPS, PCS, GSM and terrestrial radio slot antenna elements are etched in a ground plane on an opposite side of the same printed circuit board. In an alternate embodiment, the GPS and satellite radio patch antenna elements are elements mounted on one printed circuit board and the AMPS, GSM, PCS and terrestrial radio slot antenna elements are etched in a ground plane on another printed circuit board rigidly secured orthogonal to the GPS and satellite printed circuit board. The AMPS, GSM and PCS circuit board can be curved to reduce the nulls at the edges of the circuit board. Further, the edge of the AMPS, GSM and PCS circuit board that contacts the GPS and satellite radio circuit board can have a saw-tooth pattern so that edge currents are reduced.

Abstract: A gas jet nozzle (20, 60) for an extreme-ultraviolet light (EUV) source, including a housing (22, 62) having a front (24, 64) and a back (26, 66). The housing (22, 62) is coupleable to a primary gas source (44) and a secondary gas source (46) and is adapted to. expel primary gas (36, 76) and secondary gas (42, 82) from the housing front (24, 64). The housing (22, 62) has a gas-expelling primary channel (39, 70) located centrally within the housing (22, 62) and a gas-expelling secondary channel (34, 74) proximate the primary channel (39, 70). The primary channel (39, 70) may be circular and the secondary channel (34, 74) may be annular, surrounding the primary channel (39, 70). A secondary gas stream (42, 82) expelled from the secondary channel (34, 74) restricts the lateral expansion of a primary gas stream (36, 76) expelled from the primary channel (39, 70), optimizing gas jet properties and reducing heating and erosion of the nozzle (20, 60).

Abstract: An optical communication system (20) is provided for transmitting a multi-rate data signal between a transmitter (22) and a receiver (24) in a power efficient manner. The optical communication system (20) includes an optical source (32) that supplies an optical carrier signal; an encoder (44) that receives and encodes a data signal; an external phase modulator (42) that modulates the optical carrier signal with the encoded data signal, such that the modulator (42) varies the duty factor of the modulated optical signal based on the encoded data signal; and an optically saturated erbium doped fiber amplifier (36) that amplifies the modulated optical signal prior to transmission by the transmitter (22). In accordance with the present invention, the modulation scheme of the optical communication system (20) varies the duty cycle of the modulation to attain power efficiency during periods of low data demand.

Abstract: A power control system for a multi-carrier base station transmitter is capable of controlling power levels of individual RF carriers. The power control system has a multi-channel amplification system for converting a plurality of analog input signals into a plurality of amplified carrier signals. The amplification system also generates a plurality of reference signals corresponding to the amplified carrier signals. Furthermore, the amplification system generates a multi-carrier signal, where the multi-carrier signal includes a summation of the amplified carrier signals. A correlating power detection system is connected to the amplification system, where the correlating power detection system generates total power control signals based on the reference signals and the multi-carrier signal.

Abstract: A circuit layout for a lumped element dual-balun (248) where the elements of the dual-balun (248) are patterned on a monolithic substrate (250) in a compact design. The dual-balun (248) includes four inductors (252, 254, 256, 258) and four capacitors (340, 342, 360, 388) electrically coupled together to provide two zero phase RF output signals and two 180° phase RF output signals. The inductors (252, 254, 256, 258) are symmetrically disposed in a rectangular area on the substrate (250). A first pair of the inductors (252, 254) is positioned at one end of the rectangular area, and a second pair of the inductors (256, 258) is positioned at an opposite end of the rectangular area. The capacitors (340, 342, 360, 388) are formed on the monolithic substrate (250) in a central circuit area (260) between the first pair (252, 254) and the second pair of inductors (256, 258).

Abstract: A bi-directional amplifier (10) for a transceiver module for amplifying both transmit signals and receive signals propagating in opposite directions. The amplifier (10) includes first and second common gate FETs (22, 24) electrically coupled along a common transmission line (20). A first variable matching network (28) is electrically coupled to the transmission line (20) between a transmit signal input port (12) and the first FET (22), and a second variable matching network (30) is electrically coupled to the transmission line (20) between a receive signal input port (14) and the second FET (24). An interstage variable matching network (32) is electrically coupled to the transmission line (20) between the first and second FETs (22, 24). A DC voltage regulator (34) provides a DC bias signal to the matching networks (28, 30, 32) and the FETs (22, 24) so that different signal amplifications and different impedance matching characteristics can be provided for the transmit signal and the receive signal.

Abstract: A nozzle (46) for a laser-plasma EUV radiation source that provides thermal isolation between the nozzle body (48) and the target material flowing therethrough. A target delivery tube (72) is provided that extends through the nozzle body (48). The delivery tube (72) has an expansion aperture (80) positioned behind an exit collimator (50) of the nozzle body (48). The delivery tube (72) is made of a low thermal conductivity material, such as stainless steel, and is in limited contact with the nozzle body (48) so that heating of the nozzle body (48) from the plasma does not heat the liquid target material being delivered through the delivery tube (72). The expansion aperture (80) has a smaller diameter than the exit collimator (50).

Abstract: A coaxial turnstile junction (10) for combining and directing both satellite uplink and downlink signals. The junction (10) includes a tapered section (30) to provide better impedance matching of the downlink signal between a waveguide structure (14) and a plurality of symmetrically disposed downlink waveguides (38-44). The junction (10) includes a first end (26) that is in signal communication with an antenna feed horn (12). The junction (10) includes a cylindrical outer wall (28) and a cylindrical inner wall (18) that are coaxial and define an outer chamber (22) and an inner chamber (24). The outer wall (28) extends into the tapered section (30) where the tapered section (30) contacts the inner wall (18) and closes the outer chamber (22). The waveguides (38-44) are positioned around the outer wall (16) and are in signal communication with the outer chamber (22) through openings in the tapered section (30).

Abstract: A rail-to-rail charge pump circuit (60) that provides a current source and a current sink to a loop filter (62). The circuit (60) is responsive to two differential logic signals from a phase comparator (52) that compares the phase of a divided down voltage controlled oscillator signal to a reference signal. The charge pump circuit (60) employs complimentary pairs of PNP and NPN bipolar transistors. One of the input signals from the phase comparator (52) is applied to the base terminal of a bipolar transistor (104) that generates a mirror current in another bipolar transistor (108) to provide the source current. The other input signal from the phase comparator (52) is applied to the base terminal of a bipolar transistor (94) that generates a mirror current in another bipolar transistor (98) to provide the sink current. A bleed resistor (114) is coupled to the base terminal of the bipolar transistor (104) so that the circuit (60) always provides a constant phase comparator gain.

Abstract: An optical device (10) including a first semiconductor layer (12) on which is deposited a dielectric layer that is patterned and etched to form dielectric strips (14) as part of a diffraction grating layer. Another semiconductor layer (16) is grown on the first semiconductor layer (12) between the dielectric strips (14) to provide alternating dielectric sections (14) and semiconductor sections. In an alternate embodiment, a dielectric layer is deposited on a first semiconductor layer (64), and is patterned and etched to define dielectric strips (66). The semiconductor layer (64) etched to form openings (68) between the dielectric strips (66). A semiconductor material (70) is grown within the openings (68) and then another semiconductor layer (72) is grown over the entire surface after removing the dielectric strips. Either embodiment may be modified to provide a diffraction grating with air channels (20).