Abstract: A method and structure for performing data synchronization by delaying the input data for substantially one-half of the VCO signal period and then comparing the phase of the delayed input data to the VCO signal. The phase difference is filtered and controls the frequency of the VCO signal to align the VCO signal with the delayed input data. The delayed input data is clocked into a flip-flop on the opposite phase of the VCO signal to produce an output signal. In a preferred embodiment the delay of the input data for phase comparison, and the delay of the input data for the output flip-flop can be independently selected.
Abstract: In a millimeter wave monopulse first detector array for use in seeker applications in a guided missile employing quasi-optical, or Gaussian beam, signal transmission, a first detector is shown to include a patch antenna array, a mixer and a power divider in a monolithic implementation for extraction of the monopulse information in a radar receiver.
January 3, 1989
Date of Patent:
December 25, 1990
Martin R. Blustine, Eileen Conaty, Clifford A. Drubin, Thomas L. Korzeniowski
Abstract: A method and apparatus of restoring communications between a pair of nodes in a network having an arbitrary number of nodes and an arbitrary number of spans interconnecting the nodes, each span having working circuits between nodes designated for transmitting actual communications traffic and spare circuits capable of, but not designated for, transmitting actual communications traffic, the method comprising the steps of (a) establishing one or more independent communication paths between the pair of nodes through a series of spare circuits of spans interconnecting the pair of nodes and other interconnected nodes in the network; and (b) redirecting communications traffic intended for one or more failed spans interconnecting the pair of nodes through one or more of the paths.
October 19, 1988
Date of Patent:
September 11, 1990
Alberta Telecommunications Research Centre
Abstract: A method and apparatus is described for transmitting and receiving data signals and voice band signals over a single pair of wires, wherein the energy content of the data signals in the voice bands is transferred to a higher frequency to avoid interference between the two. This is accomplished by sinusoidally encoding the data pulses in the frequency domain. The encoding is equivalently performed in the time domain by linearly combining weighted delayed and advanced versions of the data pulses, in accordance with a weighting formula. A transversal filter is used to multiple delayed and advanced versions of the data pulses by a scaling factor times the ratio of m!/(m-i)!i! factorial wherein i is the ith version being weighted, m is an integer greater than one and ! indicates the factorial function.
Abstract: An interference cancelling system for cancelling or minimizing multiple signal components of a received signal in a radio receiver caused by an interfering signal from a radio transmitter which interfering signal follows multiple paths to the radio receiver includes a directional coupler which samples the interfering signal transmitted from the radio transmitter and provides a primary sample signal, a transmission link which defines a primary sample signal path from the radio transmitter to the radio receiver, a power splitter for dividing a portion of the primary sample signal path into a plurality of secondary sample signal paths, a power combiner for combining the plurality of secondary sample signal paths back into the primary signal path, and a 180.degree. hybrid coupled to the primary sample signal path and to the radio receiver. The secondary sample signal paths include delay lines and attenuator pads.
Abstract: A simple balanced-mixer circuit that uses the resistive channel of a GaAs MESFET exhibits superior intermodulation performance, with other performance parameters, e.g., conversion loss, port impedances, and LO sensitivity, being equal to or better than other diode mixers.
Abstract: An RF power supply serves to supply a regulated power amplified RF drive signal to an RF transmitter. The supply includes an RF oscillator for providing an RF input signal. A DC voltage source provides a DC voltage V. A plurality of power amplifiers are provided with each receiving the input RF signal and each having an input for receiving a DC voltage signal, and each serving to amplify the input RF signal by an amount dependent upon the magnitude of the DC voltage signal supplied to its input and thereby provide an amplified RF signal. The amplified RF signals are combined to provide an RF drive signal. The DC voltage V is directly supplied to the input of at least a first one of the power amplifiers.
Abstract: A multiple port signal regenerator for facilitating communication between a plurality of (two or more) computers and computer peripheral devices ("computer products") in a local access network. The regenerator includes logic circuits that: (1) receives, processes and transmits an incoming message from a source computer product and ignores subsequently received incoming messages from other computer products until the first-received message is processed; (2) suppresses or ignores, for a predetermined punishment time interval, subsequent messages received from a source computer product, if temporal length of a message received from the source exceeds a predetermined protocol time interval; and (3) after the end of a message is received, determines when the lines of a network are all idle so that the regenerator can be re-activated to receive another incoming message from a computer product in the network.
Abstract: A cathode ray tube with an electrophoretic getter device incorporated therein is described. The electrophoretic deposition, in the form of a porous coating, of at least one getter material and simultaneously an antisintering agent on any form of getter support is also described. The getter material may be a powder of a metal, of a metal alloy or of a hydride thereof, or a mixture of these components.
Abstract: Compensation for rain fades in a VSAT communications network is obtained by a uplink power control mechanism incorporated in a master station, which maintains the power output level of the satellite transponder constant without incorporating excessive static margins into the link power budget. A variable attenuator, which controls the output power of the master station's high power amplifier is initially set at a prescribed level which will produce the intended satellite amplifier EIRP for a `clear sky` condition. The master station monitors the output of the satellite amplifier and derives a measure of the signal-to-noise ratio of downlinked signals. Knowing the variable attenuator setting and the signal-to-noise ratio of the downlinked signals, the magnitude of attenuation of outlink carrier frequency signals transmitted from the master station to the satellite is determined.
Abstract: An FM receiver capable of generating a signal showing the electric field intensity of a received signal. More particularly, an FM receiver capable of generating a signal showing the electric field, wherein the dynamic range is expanded, and the linearity is improved. The enlargement of the dynamic range of the signal showing the electric field intensity may be effected, and also the linearity may be improved. Accordingly, the electric field intensity of the received signal may be correctly displayed by a display, etc. Especially, as the gain control is effected through the control of the operation current of the gain control amplification circuit in accordance with the gain control signal by the differential type of level detection circuit, an FM receiver suitable for IC may be provided.
Abstract: The signalling network has a main control unit which can communicate with any of a number of home units each associated with a separate household. Some home units have signal-repeater facilities. Each of the control units and the home units has an address identity unique in the network.When a signal is sent out targeted at a specific home unit, the main control unit monitors for acknowledgement of reaching its destination. If no such acknowledgement is received, the main control unit sends out the signal again, but re-routed via an intermediate home unit with a repeater facility.
Abstract: When driving a thin-film EL display panel having groups of two electrodes on opposing sides of a thin-film EL layer, a voltage is applied so that the polarity of the AC pulse applied to the intersection (picture element) of opposing electrodes is the reverse of the polarity of the AC pulse applied simultaneously or nearly simultaneously to adjacent or nearly adjacent picture elements. This drive method avoids flicker caused by differing luminance intensities resulting from alternating polarity in EL matrix-type displays.
Abstract: A rapid scanning radio with multi-mode local oscillator control. In one embodiment a phase-locked loop is closed for tuning to all frequencies of interest, and each time the loop locks a DAC is loaded with successive digital values until a value corresponding to the steady-state VCO tuning voltage is found for the currently tuned channel. That digital value is stored for later recall as the tuning value for that channel. Once digital values are determined for all the tunable frequencies in the radio, the loop is opened for high-speed scanning under open-loop control of the DAC.
Abstract: Apparatus for distributing the processing of data across a plurality of loci of control which are connected by a mail system. The apparatus includes a package which contains files of various types and a route specifying the order in which the package is to be circulated among the loci and the processing to be done at each locus. Each locus includes programs executable by users which can manipulate the contents of the package. The programs automatically take the type of file being manipulated into account. The manipulations include modifying the unexecuted portion of the route. Each locus further includes a process which executes the route as modified, a process which tracks the package and receives control commands, and a process which handles errors detected by the other components or by users. The tracking processes maintain data bases for locating the package.
December 19, 1986
Date of Patent:
June 5, 1990
Wang Laboratories, Inc.
Roger H. Dev, Gabriel Steinberg, John B. Kam, Stewart A. Comer
Abstract: The invention relates to a transfer arrangement comprising a plurality of stations that are connected to each other via separate write lines and read lines, the write line at one position being coupled to the read line. The information transfer from one station to another is effected through a data channel that is formed by an allocated time slot in periodic frames. In order to realize an improved use of the data channel in the case of mutually simultaneous information exchange between two stations, according to the invention only one data channel is occupied through which each station reversibly links the information arriving through the incoming write line to the information to be transferred, preferably by means of an exclusive OR gate, and in addition, each station links the received information again to the transferred information, thus recovering the information transferred by the other station.
Abstract: A single-level multiplexer (70) has a plurality of stages (72-78), one for each bit. In each stage, a select transistor (84) has a current path coupling an output node (86) to a common node (88), and a control element that is coupled to a select signal line (80). A data transistor (90) has a current path connecting a voltage supply (92) to the common node (88), and a control element connected to a data signal source (82). Common node (88) is connected to a current source (94, 96, 98, 100). The output node (86) of each stage is coupled together with the output nodes of the other states to an output (108) of the multiplexer.
Abstract: An apparatus and/or method for generating a digital clock signal which is frequency and phase referenced to an external digital data signal is disclosed. The external digital data signal is typically subject to variations in data frequency and high frequency jitter unrelated to changes in the data frequency.
Abstract: The present publication describes a method for the transmission of control signals to the row drive circuits in the control of thin-film electro-luminescent displays. According to the method, as control signals are used, a data signal, a clock signal, a signal that activates all the input stages of the row drive circuits at the same time, i.e., a strobe signal, and two signals by means of which the drive circuits controlling either odd rows or even rows are chosen to be activated (odd row enable and even row enable). According to the invention, all the control signals are transmitted via one first line (A) and one second line (B), whereby the timings of the pulses on the first line (A) and on the second line (B) are chosen so that the signal of the first line (A) is a combined odd (or even) row enable and data signal and the signal of the second line (B) is a combined even (or odd) row enable and clock signal.
Abstract: In the pulsed FM system, the input signal is first modulated into the pulse FM signal. Thereafter, this pulse FM signal is modulated into the pulsed FM signal by the frequency divider. This pulsed FM system is suitable to CATV.