Abstract: A variable displacement vane-type fluid pump is provided which permits improved regulation of the pump discharge such that the pump can meet the various requirements of lubrication for internal combustion engines at all speeds with minimized use of power. Of course, the vane pump may also be utilized in a wide range of power transmission and other fluid distribution applications. The vane pump of the invention may also use both hydrostatic and mechanical actuators to control the position of its containment ring or eccentric ring and hence, regulate the output of the pump. According to yet another aspect of the present invention, to prevent inlet flow restriction or cavitation, a valve may be provided to permit some of the pump outlet or discharge flow to bleed into the pump inlet to provide needed velocity energy to the fluid flow into the pump inlet.

Abstract: A cascadable divide-by-two binary counter circuit (120) that has particular application for use as a synchronous divider circuit (50, 54) in a phase lock loop (26). The counter circuit (120) employs a D flip-flop (122) that receives a D input and provides a Q output. A first AND gate (124) is responsive to a P input and a Q input, where the Q input is the output from a preceding counter circuit and the P input is the state of all of the preceding counter circuits. The output of the AND gate (124) is applied to an exclusive-OR gate (126) along with the Q output of the flip-flop (122). The output of the exclusive-OR gate (126) is applied to one input of a second AND gate (128). The other input of the second AND gate (128) is a reset signal and the output of the second AND gate (128) is the D input of the flip-flop (122). A decoder (142) is programmed to provide the reset signal when the desired count is reached.

Abstract: A superconducting oscillator/counter analog-to-digital converter (50) that provides simultaneous in-phase and quadrature-phase of an RF input signal. The RF input signal is converted to a series of SFQ input pulses by a superconducting voltage controlled oscillator (12). A clock circuit (26) generates a series of SFQ clock pulses. The SFQ input pulses and the SFQ clock pulses are applied to a pulse repulsion circuit (52) that outputs the SFQ input pulses and the SFQ clock pulses spaced apart in time. In one embodiment, the pulse repulsion circuit (52) includes two Josephson transmission lines (60, 62), where the magnetic coupling between the lines (60, 62) provides the SFQ pulse repulsion.

Abstract: An apparatus for and a method of generating an envelope predistorted radio frequency signal. A complex baseband signal, having an in-phase component I and a quadrature component Q, is sampled and filtered. The magnitude uk of each complex baseband sample pair is determined by the square root of the sum of the squares of the in-phase component sample and the quadrature component sample. A distortion factor Dk, is determined based on a scaled value of the inverse hyperbolic tangent or archyperbolic tangent (“atanh”) of the baseband sample magnitude divided by that scaled sample magnitude. Each sample of the in-phase component Ik and of the quadrature component Qk is multiplied by the corresponding distortion factor Dk so as to provide predistorted components. The predistorted components are then combined to provide a predistorted baseband signal.

Abstract: Demodulating a DPSK encoded data signal. The received signal has a symbol tracking value determined in a synchronization circuit. Doppler error in the signal is estimated. The signal, the symbol tracking value, and the estimated Doppler error are applied to a demodulator within which the signal is multiplied by a signal at a frequency which is the negative of the estimated Doppler error to remove that Doppler error. The resulting signal is filtered and decimated and normalized to generate the arctangent of the in-phase and quadrature components of the baseband signal. This arctangent signal is stripped of phase angle modulation and applied through loops to remove derivatives of the input phase signal. The arctangent and the resulting angles are mapped in a nearest neighbor map circuit, and the difference between successive angles is applied to a gray code to binary mapping circuit which detects the encoded data.

Abstract: An EUV radiation source (12) that generates a sheet (36) of a liquid target material that has a width that matches the desired laser spot size (28) for good conversion efficiency and a thickness that matches the laser beam/target interaction depth. The EUV source (12) includes a reservoir (10) containing a pressurized cryogenic liquid target material, such as liquid Xenon. The reservoir (10) also includes an array (14) of closely spaced orifices (16). The liquid target material is forced through the orifices (16) into a vacuum chamber as separated liquid stream filaments (20) of the target material that define the sheet (36). The liquid streams freeze to form an array of frozen target filaments (20). A laser beam (24) is directed to a target area (28) in the vacuum chamber where it irradiates the stream of filaments (20) to create a plasma (30) that emits EUV radiation (32).

Abstract: This invention is a pivot assembly 10 that connects mirror head 11 and a mirror mounting bracket 12 of a rear vision mirror that comprises a spigot 17, a plate 14 with an aperture 26 that is journalled to the spigot 17. A detent is located between the plate 14 and the spigot 17 which holds these components together to in turn hold the mirror head 11 in at least one required position with respect to the mirror mounting bracket 12. The detent changes from a locked position where the plate 14 is held with respect to the spigot 17 to a disengaged position when the plate 14 is rotated with respect to the spigot 17. A spring 40 acts against the detent to hold it in its locked position. The spring 40 yields to allow the detent to move to its disengaged position as the plate 14 is rotated with respect to the spigot 17. An attachment mechanism is provided both on the spigot 17 and the plate 14 that allows the spigot 17 to be secured to either one of the mirror head 11 or mirror mounting bracket 12.

Abstract: A data structure according to the invention is created in memory of a computer for storing data objects for access by a computer application that is executed by the computer. Each of the data objects is associated with a key. The data structure includes a root node object. Additional node objects are added to the root node object based on the characters in the key. The depth of the data structure is equal to the number of characters in the keys. The data structure is ideally suited for efficiently sorting the data objects.

Abstract: A downlink scheduler (20) is provided for scheduling the downlink transmission of data cells in a spot beam processing satellite (12). The downlink scheduler (20) includes a beam selector (48) for selecting one of the spot beams associated with the satellite (12), a plurality of wholesale selectors (50) for selecting one of a plurality of wholesalers, such that each of the wholesale selectors (50) is associated with one of the spot beams, and a plurality of retail selectors (52) for selecting one of a plurality of retail connections, such that each of the retail selectors (52) is associated with one of the wholesalers. Each of the selectors may use a packet fair queuing (PFQ) method to make its selection. The downlink scheduler (20) then passes at least one data cell from a selected retail connection to a downlink modulator (24), thereby scheduling the downlink transmission of data cells in the satellite.

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 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 method for controlling a solenoid using a single coil solenoid for both course and fine adjustment. A resistor or series of resistors may be used in parallel/for current controlled solenoids or in series for voltage controlled solenoids for allowing course or finite control of the solenoids.

Abstract: An electric positional actuator that includes a default device for positioning the actuated device in a default position. The actuator includes an electric motor that controls the rotational position of a shaft through a gear system. When the shaft rotates, it moves a link-bar that actuates the actuated device. A rotational sensor coupled to a printed circuit board detects the position of the shaft, and provide a feedback signal of the shaft's position. The default device includes a spring wrapped around the shaft. When the link bar is rotated away from its default position, one leg of the spring remains in contact with a housing spring boss while the other leg of the spring is in contact with the link bar opposing the movement and trying to return the link-bar to the default position.

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.