Coupling Networks Patents (Class 333/24R)
  • Patent number: 6137375
    Abstract: A circuit for controlling the loss of a VCO in a master-slave tuning system includes an envelope detector, an amplitude regulator, a current-mode circuit, and a low-pass filter. The envelope detector receives the VCO output voltage and provides VCO output envelope voltage, V.sub.ENV. The amplitude regulator receives V.sub.ENV and a reference voltage, V.sub.REF, and provides a sourcing current if V.sub.ENV is less than V.sub.REF, and draws a sinking current if V.sub.ENV is greater than V.sub.REF. The current-mode circuit receives V.sub.ENV and provides a control current, I.sub.Q. The low-pass filter has high DC gain for integrating the control current and the sourcing or sinking current to provide the VCO control voltage, V.sub.CON, to the VCO. The control current, I.sub.Q, is proportional to the inverse of V.sub.ENV multiplied by the time derivative of V.sub.ENV.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: October 24, 2000
    Assignee: The Trustees of Columbia University in the City of New York
    Inventor: Dandan Li
  • Patent number: 6130812
    Abstract: Provided is a protection circuit for high speed signal communication via a two-wire connection between the two output terminals of a PECL driver and the two input terminals of a PECL receiver. The PECL driver and receiver are supplied with power from individual power supplies. The protection circuit includes two diodes connected in series with a respective wire with their cathodes electrically coupled to the respective output terminal of the PECL driver and their anodes electrically coupled to the respective input terminal of the PECL receiver, and two resistors connected between the PECL receiver power supply and the anodes of the respective diode. The resistance of the resistors ensures forward biasing of the diodes when the receiver power supply is supplying power. A capacitor may be connected in parallel with the respective diodes.
    Type: Grant
    Filed: December 28, 1998
    Date of Patent: October 10, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventors: Giorgio Corvasce, Luca Calcaterra
  • Patent number: 6111918
    Abstract: A plurality of stations (S), for instance measuring probes, preferably comprising respective microprocessors (KL), are connected successively to a common two-wire line (SL). Supply voltages and synchronization signals are distributed through this line (SL) from a central unit (CU), and at the same time a full duplex communication between single stations (S) and the central unit (CU) is enabled.
    Type: Grant
    Filed: October 3, 1997
    Date of Patent: August 29, 2000
    Inventor: Einar Gotaas
  • Patent number: 6097262
    Abstract: A transmission line impedance matching apparatus is disclosed that limits longitudinal signals and matches the longitudinal characteristic impedance between two conductors and comprises a common mode choke and an impedance matching device. The common mode choke, comprising two windings wound in the same direction, acts as a high impedance to longitudinal high frequency signals. As a result of this, standing waves are caused by the metallic signals reflecting off the choke. The impedance matching device, comprising two windings wound in the same direction, provides a good match to the longitudinal characteristic impedance and thus reduces standing longitudinal waves and reflections. The apparatus may include a terminal corrector or a mid-line corrector, or a combination thereof. This invention may allow greater bandwidth to be dedicated to services and allow transmission over longer subscriber loops before the minimum S/N ratio is achieved.
    Type: Grant
    Filed: April 27, 1998
    Date of Patent: August 1, 2000
    Assignee: Nortel Networks Corporation
    Inventor: R. Alan Combellack
  • Patent number: 6034576
    Abstract: A line coupling assembly contains a carrier plate of an electrically insulating material with first and second opposite surfaces. A first electrically conductive layer at least partially covers the first surface. A first line section is arranged on the first surface so as to be electrically insulated from the first layer. A second electrically conductive layer at least partially covers the second surface. A second line section is arranged on the second surface so as to be electrically insulated from the second layer. A line segment runs from the first surface to the second surface. First and second switches for bilateral electrical connection of the line segment to the first and second layers or to the first and second line sections are arranged on the first and the second surfaces, respectively.
    Type: Grant
    Filed: September 15, 1998
    Date of Patent: March 7, 2000
    Assignee: Siemens Aktiengesellschaft
    Inventor: Rainer Kuth
  • Patent number: 6034995
    Abstract: The transmission of data via a differential bus by means of balanced signals is not only reliable, but also offers the advantage that in the event of various single faults, i.e. faults concerning only one of the two lines or faults where the two lines of the differential bus are short-circuited, data transmission is still possible, be it with a reduced reliability. To this end, both lines are connected to a number of comparators which have different threshold values so that the nature of a fault occurring can be determined and, in dependence thereon, the comparator output can be determined wherefrom the recovered data signal must be derived.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: March 7, 2000
    Assignee: U.S. Philips Corporation
    Inventors: Harald Eisele, Robert Mores
  • Patent number: 6031432
    Abstract: This invention discloses a balancing circuit for providing a substantially fixed level of attenuation within a given return path frequency passband, while preventing noise related harmonics from distorting signal transmissions within the return path frequency passband. The balancing circuit includes coupling capacitors which are connected in series between input and output end nodes. A series connected inductor and capacitor pair is connected between each of the input and output end nodes and ground to form end sections. Another inductor is connected between the coupling capacitors and ground. A resistor is connected in parallel with the respective capacitor of each end section. The balancing circuit is placed in series at each subscriber port, and may be mounted on a printed circuit board and enclosed within a tubular housing with mating male and female "F" connections.
    Type: Grant
    Filed: February 27, 1998
    Date of Patent: February 29, 2000
    Inventor: Ronald C. Schreuders
  • Patent number: 6025760
    Abstract: A tool is described for shunting a multi-tap for an RF cable system by connecting a low-pass filter between an unused input port and an unused output port of the multi-tap. The components of the filter are such as not to interfere with the circuits of the multi-tap when both are in the circuit. A light is provided for indicating when the tool is in operative position.
    Type: Grant
    Filed: May 1, 1998
    Date of Patent: February 15, 2000
    Inventor: Danny Q. Tang
  • Patent number: 6016086
    Abstract: A bus for high signal quality interconnections, comprising means for producing at least one common mode reflection, often for differential transmission line interconnections. Also, a bus for high signal quality interconnections further comprising means for under-damping the signal and/or reducing the common mode noise. In both cases the means are at least one impedance termination. To produce common mode reflections, there are non-contact couplers terminated by short and open circuits, which cause the reflections from via connectors and other like impedance discontinuities to be re-reflected in common mode so that they are rejected by a differential receiver. To produce under-damping of the signal and/or a reduction of the common mode noise, capacitive terminations are used. The under-damping of the signal sharpens in the falling edge of the coupler pulses.
    Type: Grant
    Filed: April 3, 1998
    Date of Patent: January 18, 2000
    Assignee: Nortel Networks Corporation
    Inventors: John M. Williamson, Alexandre J. Guterman, Robert Zani, Terry Newell, Anthony K. Dale Brown
  • Patent number: 6005452
    Abstract: The present invention relates generally to filtering in e.g. mobile telephony. A new input loop is introduced wherein the input loop is fixed in its physical relation to the H-field. One end of this input loop is arranged to form a capacitance or an inductance which is then used to adjust the location of the maximum current node in the loop. The adjustment of the position of this maximum current node thereby adjusts the bandwidth of the RF signal. The fixing of the loop has the advantage of simplifying the procedure for tuning the filter. It also has the advantage of reducing the number of tools required for tuning, thereby allowing for a reduction in size occupied by the filter and isolator arrangement, and a reduction in the cabling and materials used.
    Type: Grant
    Filed: December 18, 1997
    Date of Patent: December 21, 1999
    Assignee: Telefonaktiebolget LM Ericsson
    Inventor: Christer Ahlberg
  • Patent number: 6002331
    Abstract: A communication line identification apparatus and method which automates the identification of communication line is engaged with a particular adapter within a communications system. A communication transducer (140) is mounted on a connector (122) of the communication line (118). The communication transducer (140) contains identification information for the communication line (118). Mounted near the adapter (114) which engages the connector (122), is an adapter transducer (138) which receives the identification information from the communications transducer (140). This identification information is transmitted to a system controller which provides the communication systems operator with the information about which communication line is connected to which adapter.
    Type: Grant
    Filed: July 20, 1998
    Date of Patent: December 14, 1999
    Inventor: Herzel Laor
  • Patent number: 5990758
    Abstract: A high-frequency signal branching device comprises a main body having an input terminal and an output terminal for connecting trunk cables on an input and an output side, respectively, and a branch body having a branch terminal for connecting a branch cable. This construction allows the number of branch terminals to be increased by replacing the branch body while keeping the main body intact. A branching circuit for branching a high-frequency signal from the trunk cable is provided in the branch body. Accordingly, the branching circuit also can be replaced by replacing the branch body.
    Type: Grant
    Filed: June 20, 1997
    Date of Patent: November 23, 1999
    Assignee: Masprodenkoh Kabushikikaisha
    Inventor: Hiroshi Matsubara
  • Patent number: 5978417
    Abstract: An adaptive cable equalizer is provided with a simple architecture, wherein a single control structure: controls the adaptation of the filter for compensating for cable length while simultaneously compensating for process and temperature variations; optimizes the SNR at any cable length by controlling biasing current sources; and uses a two-stage architecture which eliminates start-up problems and optimizes output levels to obtain optimal dc restoration while simultaneously allowing for independent optimization of the output levels of the recovered data in accordance with other requirements as desired. An analog adaptive equalizing filter is used for accurately synthesizing the inverse transfer function of cables of variable lengths. Data rates up to and beyond 400 Mbps are supported and the adaptive behavior automatically compensates for different cable lengths as well as process variations (with respect to the process(es) used for fabricating the equalizer in a monolithic form) and temperature variations.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: November 2, 1999
    Assignee: National Semiconductor Corporation
    Inventors: Alan J. Baker, Marc H. Ryat
  • Patent number: 5945634
    Abstract: A method of forming a tap into an intermediate point on a continuous coaxial cable, and a coaxial cable tap housing suitable for forming such a tap. The tap housing includes a recess and an alignment element having a predetermined spatial relationship with the recess. The recess has an entry, an exit and a passage connecting the entry and exit. When the tap housing is fixed to a cable, the exit of the recess is closer to the outer conductor of the cable than the entry of the recess is to the outer conductor. The alignment element is used to position a cutting tool which is inserted through the entry of the recess to form an opening in the outer conductor and a cavity in the dielectric under the opening. A tap insert, which includes a coupler assembly, is mounted to the housing, and the coupler assembly is inserted through the entry of the recess and through the opening into the cavity formed in the cable. In specific embodiments, the recess and opening are elongated.
    Type: Grant
    Filed: June 5, 1996
    Date of Patent: August 31, 1999
    Assignee: Raychem Corporation
    Inventors: Gerald L. Shimirak, Philip Vail, Alexandru S. Gliga, Nelson M. Shen, Nils Wydler, Gary Wagner, Mel Nance
  • Patent number: 5939965
    Abstract: An inductive component with variable magnetic properties. A magnetic field is inductively generated in a magnetic core by an electrical winding. Electrode coatings are provided on the magnetic core and an electrical field or current is impressed into the magnetic core through the electrodes.
    Type: Grant
    Filed: March 18, 1997
    Date of Patent: August 17, 1999
    Assignee: Siemens Matsushita Components GmbH & Co. KG
    Inventors: Mauricio Esguerra, Helko Meuche
  • Patent number: 5929718
    Abstract: An interface device permits installation of a video system by direction broadband RF signals from an outdoors transmission line to an indoors receiver and by providing electrical power from the receiver to the transmission line for the antenna electronics without requiring a hole for passage of a coaxial cable. Power transmission circuitry includes a first inductor mounted adjacent the first side of a window and connected to the first transmission line to receive DC electrical power therefrom. A square wave drive signal is applied to switch apparatus that converts the DC power received by the inductor into time-varying electrical signals that produce a time-varying magnetic field. A second inductor that is part of a resonant circuit mounted adjacent the dielectric layer opposite the first inductor receives the transmitted power via magnetic induction.
    Type: Grant
    Filed: March 17, 1997
    Date of Patent: July 27, 1999
    Assignee: Multiplex Technology, Inc.
    Inventor: John B. Crosby
  • Patent number: 5923228
    Abstract: An S/N enhancer is provided which can be formed to be small in size and in which impedance matching can easily be achieved. The S/N enhancer includes two magnetostatic wave elements. First to fourth transducers each in the shape of a single line are disposed on YIG thin films of the magnetostatic wave elements in parallel and spaced from one another. An input terminal is connected to one end of the first transducer. An attenuator is connected between the other end of the first transducer and one end of the third transducer. A 180.degree. shifter and another attenuator are connected in series between one end of the second transducer and one end of the fourth transducer. An output terminal is connected to the other end of the fourth transducer. The other ends of the second and third transducers are respectively grounded.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: July 13, 1999
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Takekazu Okada, Satoru Shinmura, Fumio Kanaya, Akira Toba, Toshihiro Nomoto
  • Patent number: 5909154
    Abstract: A continuity bridge in a broadband signal tap for providing a make-before-break connection of an input terminal to an output terminal of the tap. The broadband signal tap comprises a housing and a cover that is removably connected to the housing. The interior of the housing has an input terminal for receiving a signal from the feeder cable and an output terminal for returning the signal to the feeder cable. The cover includes circuitry for splitting the signal and delivering a portion thereof to at least one subscriber port on the cover. The cover has an input socket and an output socket, each being removably engaged with and electrically connected to the input and output terminals, respectively, of the housing. The continuity bridge in the housing connects the input terminal to the output terminal upon the removal of the cover from the housing prior to the disengagement of the sockets from the terminals.
    Type: Grant
    Filed: June 2, 1997
    Date of Patent: June 1, 1999
    Assignee: Antec Corporation
    Inventors: James T. Brown, Dennis J. McLain, Mark E. Adams
  • Patent number: 5892411
    Abstract: A data transmission device has a first module and a second module moveable relative to one another. One of the modules functions as a sending module and the other functions as a receiving module for transmitting data between first and second modules. One of the modules is an electrical line with a defined surge impedance and the other module is a coupling probe for coupling contact-free with the electrical line. A first sending and receiving electronic circuit is connected to the first module. A second sending and receiving electronic circuit is connected to the second module.
    Type: Grant
    Filed: February 15, 1996
    Date of Patent: April 6, 1999
    Assignee: Ulrich Schwan
    Inventors: Ulrich Schwan, Andreas Nagel
  • Patent number: 5812597
    Abstract: A receiver for a LAN which uses a transformer for isolation. Base line wander is prevented by use of a positive feedback path which provides a signal that compensates for low frequency loss through the transformer. The feedback path connects the output of the receiver to the secondary winding of the transformer. The time constant of the transformer and terminating resistor L/R equals the RC time constant in the feedback path.
    Type: Grant
    Filed: January 30, 1996
    Date of Patent: September 22, 1998
    Assignee: Tut Systems, Inc.
    Inventors: Martin H. Graham, Matthew Taylor
  • Patent number: 5764114
    Abstract: An electro-magnetic pulse filter which can be used simultaneously for a plurality of frequency bands includes a housing (20) mounted in the outer conductor (10) and a .lambda./4 short-circuiting conductor (24), which is connected in an electrically conductive fashion to the inner conductor of a coaxial line (30) and is connected in an electrically conductive fashion to the end face of a housing (20). Arranged between the housing (20) and the short-circuiting conductor (24) is at least one sleeve (25) which is connected to the latter in a conductive fashion. The length of the short-circuiting line (24) corresponds to the .lambda./4 length of the lowest frequency band transmitted. Considered together, the sleeves (25, 26) produce a number of cavity resonators which are connected in series and are tuned with their length to various midband frequencies.
    Type: Grant
    Filed: March 28, 1996
    Date of Patent: June 9, 1998
    Assignee: Huber & Suhner AG
    Inventor: Gregor Kuhne
  • Patent number: 5731269
    Abstract: An adjustable coupler for coupling electromagnetic energy into or out of a resonant cavity has an input/output line connected to a loop or conductor. A base of the coupler has a passageway into which a bolt is inserted. Threads on a bolt engage threads on a nut attached to the conductor. A head of the bolt is held in place on the outside of the base so that rotation of the head moves the nut and conductor.
    Type: Grant
    Filed: November 13, 1995
    Date of Patent: March 24, 1998
    Assignee: Illinois Superconductor Corporation
    Inventor: Craig Robert Clermont
  • Patent number: 5656873
    Abstract: A device for charging PFLs (Pulse Forming Lines) on a time scale of a few nanoseconds. The device includes a source transmission line (STL) connected through a switch to a pulse forming transmission line. The source line is initially charged while the PFL is uncharged, and the switch is open. The impedance of the STL is larger than the impedance of the PFL. The impedance of the STL is also tapered in order to effect an energy transfer efficiency approaching 100% from the STL to the PFL. In operation when the switch is closed, energy flows from the source line to the PFL. As the energy and voltage build on the PFL, an output switch closes and delivers the energy of the PFL to the output transmission line section. The impedance of the output transmission line section is matched to the PFL impedance so that all of the energy in the PFL flows into the output section in the form of a pulse.
    Type: Grant
    Filed: February 7, 1996
    Date of Patent: August 12, 1997
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: James P. O'Loughlin, Diana L. Loree
  • Patent number: 5648745
    Abstract: A method and system for distributing multimedia signals to a subscriber from a headend unit. The multimedia signals are transmitted on a network media as an RF signal. The RF signal is fed to an input terminal of a tap which has an RF circuit that splits the RF signal and distributes to an output terminal. The RF circuit splits the RF signals, and feeds the split signal to a plurality of connectors on the tap's front panel. The RF signals on the output terminal are fed downstream to a plurality of subscribers. A plate is placed in the tap such that when the RF circuit is removed for repair, maintenance or service, an electrical connection is maintained between the input and output terminal to prevent a disconnection of service downstream.
    Type: Grant
    Filed: March 21, 1995
    Date of Patent: July 15, 1997
    Assignee: Scientific-Atlanta, Inc.
    Inventors: Bart Fredrick Spriester, James Lawrence Dale
  • Patent number: 5647056
    Abstract: Method and apparatus for interfacing a peripheral to a local area network with an interactive network board connected to the peripheral via a bi-directional peripheral interface and connectable to the local area network via a local area network interface. The interactive network board executes an access management program such as a socket server to monitor the local area network for communications from a network client directed to a proprietary socket. In response to communications detected by the access management program, the access management program establishes direct communication between the network client and itself and executes commands requested by the network client, such as commands to obtain or to alter the status of the network peripheral, or commands to obtain or to alter the status of the interactive network board itself. The interactive network board may also execute a peripheral server program such as a print server in a multitasking environment with the access management program.
    Type: Grant
    Filed: November 18, 1992
    Date of Patent: July 8, 1997
    Assignee: Canon Information Systems, Inc.
    Inventors: Lorraine F. Barrett, William C. Russell, Andrew J. Kraslavsky, Robert D. Wadsworth, George A. Kalwitz
  • Patent number: 5612652
    Abstract: An interface device permits installation of a video system by directing broadband RF signals from an outdoors transmission line to an indoors receiver and by providing electrical power from the receiver to the transmission line for the antenna electronics without requiring a hole for passage of a coaxial cable. Power transmission circuitry includes a first inductor mounted adjacent the first side of a window and connected to the first transmission line to receive DC electrical power therefrom. A square wave drive signal is applied to switch apparatus that converts the DC power received by the inductor into time-varying electrical signals that produce a time-varying magnetic field. A second inductor mounted adjacent the dielectric layer opposite the first inductor receives the transmitted power via magnetic induction.
    Type: Grant
    Filed: March 4, 1996
    Date of Patent: March 18, 1997
    Assignee: Multiplex Technology, Inc.
    Inventor: John B. Crosby
  • Patent number: 5587692
    Abstract: A method for connecting together two twisted pair lines in a LAN so as to avoid common mode current. The invention recognizes that the impedance to ground is different for each wire in the twisted pair line. Moreover, this impedance is different from spool-to-spool for lines having the same purported impedance. A balun is placed at the connection between the lines.
    Type: Grant
    Filed: November 28, 1994
    Date of Patent: December 24, 1996
    Assignee: Tut Systems, Inc.
    Inventors: Martin H. Graham, Matthew Taylor
  • Patent number: 5551074
    Abstract: A mixer comprising four FET transistors in a MMIC, a reflection transformer having tri-filar windings, an IF balun, an RF balun, a local oscillator balun, a pair of load resistors, a pair of series resistors, and a pair of series capacitors. The mixer is packaged in a lidded header similar to a large TO-8 metal package.
    Type: Grant
    Filed: January 19, 1995
    Date of Patent: August 27, 1996
    Assignee: Watkins-Johnson Company
    Inventor: Michael W. Vice
  • Patent number: 5477153
    Abstract: A coupling network for electromagnetic pulsed testing arrangements includes three stacks of toroidal ferrite cores. Two of the stacks are of identical diameter, the third stack has a diameter approximately equal to the combined diameters of the first two stacks. A copper tube looped through the central aperture of the first two stacks forms a primary winding. An insulated wire looped twice through the first two apertures forms a secondary winding of a 1:2 step-up transformer. The winding is extended through the aperture of the third stack. The third stack is operable to permit the laying in of a cable connected to a device under test. The cable forms the secondary of an isolation transformer.
    Type: Grant
    Filed: June 16, 1994
    Date of Patent: December 19, 1995
    Assignee: Honeywell Inc.
    Inventor: Robert M. Murray
  • Patent number: 5467061
    Abstract: A LAN which uses flat telephone cable having at least four conductors. The inner conductors are joined together and the outer conductors are joined together at each node thereby making reversals of the inner and outer conductors, which may occur at connectors, impossible. Each node uses two baluns to provide an unbalanced zone between the baluns for connecting to the DTE.
    Type: Grant
    Filed: October 11, 1994
    Date of Patent: November 14, 1995
    Assignee: Tut Systems, Inc.
    Inventors: Charles M. Aden, Martin H. Graham, Matthew Taylor, Mark Miller
  • Patent number: 5432486
    Abstract: A coupling connector relies on inductive and capacitive coupling over a length L.sub.c to "connect" signals from a first circuit card to a second circuit card. The coupling connector includes a flex circuit which in a connected state is compressed to provide a coupling length L.sub.c between the first and second circuit cards. A typical application is for coupling cards to a backplane having a plurality of parallel, signal carrying tracks. The near end of each coupling track is input to a receiver having an input impedance equal to the characteristic impedance of the coupling track. The far end of the coupling track is terminated by a resistor whose value equals the characteristic impedance of the coupling track.
    Type: Grant
    Filed: May 20, 1993
    Date of Patent: July 11, 1995
    Assignee: Northern Telecom Limited
    Inventor: Larry K.-C. Wong
  • Patent number: 5379005
    Abstract: A LAN which uses flat telephone cable having at least four conductors. The inner conductors are joined together and the outer conductors are joined together at each node thereby making reversals of the inner and outer conductors, which may occur at connectors, impossible. Each node uses two baluns to provide an unbalanced zone between the baluns for connecting to the DTE.
    Type: Grant
    Filed: July 16, 1993
    Date of Patent: January 3, 1995
    Assignee: Tut Systems, Inc.
    Inventors: Charles M. Aden, Martin H. Graham, Matthew Taylor, Mark Miller
  • Patent number: 5351019
    Abstract: A local area network interface for a network element having redundant processors is made by using a pair of connectors for each processor. A delay line is used between pairs of connectors for non-redundant LAN configurations. For redundant LANs, the delay line is not used.
    Type: Grant
    Filed: December 15, 1992
    Date of Patent: September 27, 1994
    Assignee: Alcatel Network Systems, Inc.
    Inventors: Thomas J. McHugh, Claude M. Hurlocker, Larry W. Lemonds
  • Patent number: 5307030
    Abstract: The invention is method and apparatus for in situ mechanical adjustment of electromagnetic power coupled through an aperture or slot. In its preferred form this adjustment of coupling is achieved by electrically connecting two thin, curved conductive leaf springs (20) to ground plane (14) at the ends of the coupling aperture or slot (12). The springs (20) are curved so as to bend away from the center of the aperture or slot opening (12). The aperture or slot is usually enclosed by a metal backing cavity (22) to prevent radiation from the rear of the aperture or slot and to provide a method for mechanically adjusting the position of springs (20) over the aperture or slot (12), e.g., by adjustment of screws (24). By advancing or retracting screws (24), leaf springs (20) are caused to progressively cover or uncover aperture or slot (12), thereby adjusting the electric field across the aperture or slot (12) and the coupled electromagnetic power through the aperture or slot (12).
    Type: Grant
    Filed: September 14, 1992
    Date of Patent: April 26, 1994
    Assignee: KDC Technology Corp.
    Inventors: Ray J. King, Michael J. Werner
  • Patent number: 5283538
    Abstract: The invention relates to a device for coupling microwave power out of a first chamber (21) into a second chamber (22). For this purpose a primary antenna (2) and a secondary antenna (3) are provided, the primary antenna (2) reaching into the first chamber (21), while the secondary antenna (3) reaches into the second chamber (22). Between the first chamber (21) and the second chamber (22) there is provided a dividing wall (20) through which a current-carrying means (11) is brought, which joins together the primary antenna (2) and the secondary antenna (3).
    Type: Grant
    Filed: March 8, 1993
    Date of Patent: February 1, 1994
    Assignee: Leybold Aktiengesellschaft
    Inventors: Michael Geisler, Michael Jung, Bernhard Kessler
  • Patent number: 5272396
    Abstract: A controllable bus terminator, for providing a switchable termination on a bus having a plurality of conductors, wherein the controllable bus terminator includes a voltage regulator, a plurality of resistive networks each of the resistive networks having a first terminal and a second terminal wherein the second terminal of each of the resistive networks provides an output terminal of the bus terminator. The bus terminator further includes a plurality of electrically controllable switches, each of the switches having a first port coupled to the voltage regulator and a second port coupled to the first terminal of a corresponding one of the resistive networks wherein each of the switches couple the corresponding resistive network to the voltage regulator when the corresponding switch is in a first state and wherein each of the switches disconnect the corresponding resistive network from the voltage regulator when the corresponding switch is in a second state.
    Type: Grant
    Filed: September 5, 1991
    Date of Patent: December 21, 1993
    Assignee: Unitrode Corporation
    Inventors: Robert A. Mammano, Mark Jordan
  • Patent number: 5249224
    Abstract: A reciprocal impedance conversion network is disclosed. Such conversion network preferably is used in a reciprocal negative impedance repeater for the nonloaded cable facilities of a telephone system. Two independent voltage sources for generating reciprocal negative impedance are connected between a first port and a second port. The first port is operably connected to the first voltage source such that a series negative impedance appears at that port. This port is specifically connected to the switching equipment of the telephone system. The second port is operably connected to the second voltage source such that a shunt negative impedance appears at that port. The second port is specifically connected to the nonloaded cable facilities of the telephone system. The network further provides a frequency dependent gain circuit which is useful for equalizing the losses along the nonloaded cable facilities.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: September 28, 1993
    Inventor: Charles W. Chambers
  • Patent number: 5220296
    Abstract: A system for coupling energy between electrical and mechanical waves includes a mechanical waveguide for propagating a mechanical wave having a mechanical wavelength at a given frequency, and an electromechanical energy converter for coupling energy between electrical and mechanical waves attached to a portion of the waveguide and capable of propagating an electrical wave having an electrical wavelength substantially equal to the mechanical wavelength at the given frequency. The portion has a length, measured in units of coupled wavelength, which is selected on the basis of the reciprocal of the coupling strength of the electromechanical converter and a selected amount of wave energy to be coupled. The function is based primarily on desired efficiency and may also be an odd integer multiple of the coupling strength reciprocal, preferably one. Piezoelectric elements are the preferred electromechanical energy conversion elements.
    Type: Grant
    Filed: November 1, 1991
    Date of Patent: June 15, 1993
    Assignee: Massachusetts Institute of Technology
    Inventors: Andreas von Flotow, Nesbitt Hagood, Tomas Valis
  • Patent number: 5200717
    Abstract: An attenuator assembly (38) employs circuitry formed on an attenuator substrate (44) having short voltage divider path lengths that allow the use of low-cost divider selecting relays (58, 60, and 62) while maintaining low VSWR and aberration levels through the attenuator. An interconnect circuit board (80) provides electrical power, control signals, a ground plane shield (108), and probe coding contacts (32) for connection to the attenuator substrate. The circuits on the attenuator substrate are laser-trimmed to obtain predetermined electrical characteristics prior to assembly in a completed attenuator assembly. The attenuator substrate rests on a recess (128) formed in top margin (127) of a cavity (120) formed within a housing (42).
    Type: Grant
    Filed: April 11, 1991
    Date of Patent: April 6, 1993
    Assignee: Tektronix, Inc.
    Inventor: Michael L. Kyle
  • Patent number: 5142252
    Abstract: An audio signal transmission line comprising an additional inductance inserted in series with the line and/or coupled in parallel therewith near the load end of the line for providing a low pass filter which overcomes parasitic and dielectric capacitance of the line so as to reduce audio frequency noise generated in the line by low level and low frequency audio signals. The magnitude of the inductance used may vary widely, e.g. from 20 microhenries to 1 millihenry, depending on the length of the line and the space available.
    Type: Grant
    Filed: October 24, 1990
    Date of Patent: August 25, 1992
    Inventor: Bruce A. Brisson
  • Patent number: 5132649
    Abstract: A signal input device having a mutual inductor formed by a coil connected with a capacitor for a grounding cable in series and a coil connected with a capacitor for a signal cable in series, and a compensating capacitor connected with the series circuit composed of the capacitor and the coil on the grounding cable in parallel. The compensating capacitor serves to prevent occurrence of a voltage on the grounding cable, and accordingly only regular signals received by an antenna are transmitted. The mutual inductor prevents resonance of inductance of a lead terminal of the compensating capacitor with capacitance of the compensating capacitor.
    Type: Grant
    Filed: August 27, 1991
    Date of Patent: July 21, 1992
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yukio Sakamoto, Toshimi Kaneko, Kazuo Dougauchi, Junichiro Wata
  • Patent number: 5131028
    Abstract: A reciprocal impedance conversion network is disclosed. Such conversion network preferably is used in a reciprocal negative impedance repeater for the nonloaded cable facilities of a telephone system. Two independent voltage sources for generating reciprocal negative impedance are connected between a first port and a second port. The first port is operably connected to the first voltage source such that a series negative impedance appears at that port. This port is specifically connected to the switching equipment of the telephone system. The second port is operably connected to the second voltage source such that a shunt negative impedance appears at that port. The second port is specifically connected to the nonloaded cable facilities of the telephone system. The invention further provides a frequency dependent gain circuit which is useful for equalizing the losses along the nonloaded cable facilities.
    Type: Grant
    Filed: January 18, 1990
    Date of Patent: July 14, 1992
    Inventor: Charles W. Chambers
  • Patent number: 5130678
    Abstract: A transmission line transformer (20, 30, 31) with inherent DC isolation has two sets (22, 22') of transmission line elements (ZN) with characteristic impedances which vary from relatively high values near the transformer inputs (P1, P2) to relatively low values near an intermediate location (28, 28') are ordered in a mirror image symmetry with respect to one another relative to the intermediate location (28, 28') in plural element embodiments (20, 30). The primaries (24, 24') are connected in series, while the secondaries (26, 26') of adjacent pairs of transmission line elements (ZN, ZN') are connected in series with the series connected pair connected in parallel across the output terminals (P3, P4). A center line transmission element (CZN) at the intermediate location (28') has a substantial zero impedance, and an electrical length equal to twice that of the other elements.
    Type: Grant
    Filed: October 31, 1991
    Date of Patent: July 14, 1992
    Assignee: Rockwell International Corporation
    Inventor: Richard C. Edwards
  • Patent number: 5128686
    Abstract: A reactance buffer maintains a substantially constant reasonant frequency for an adjustable size loop antenna having first and second antenna segments. Each segment has first and second ends, the first ends being coupled to a receiver, and the second ends providing loop size adjustment. The reactance buffer comprises a reactance buffer input coupled to the second end of the first antenna segment. A plurality of taps are linearly disposed along a longitudinal axis of the first wristband section, and has a predetermined length between the outermost taps corresponding to the loop antenna size adjustment required. The taps provide selectable reactance buffer outputs for coupling to the second end of the second antenna segment. A plurality of reactance elements are arranged non-serially and couple the reactance buffer input to each of the plurality of taps and provide a substantially constant reactance measured between the reactance buffer input and each of the plurality of taps.
    Type: Grant
    Filed: August 27, 1990
    Date of Patent: July 7, 1992
    Assignee: Motorola, Inc.
    Inventors: William Tan, Robert Kurcbart
  • Patent number: 5126702
    Abstract: An arrangement for supplying current to a wideband transmission cable includes an all-pass circuit having a high-pass path (VPH) and a low-pass path (VPB) in which the signals in the transmission cable are recombined by virtue of the presence of a phase inverter. A current supply supplies current to the transmission cable via a supply point situated in the low-pass path.
    Type: Grant
    Filed: December 6, 1990
    Date of Patent: June 30, 1992
    Assignee: U.S. Philips Corporation
    Inventor: Joel Gris
  • Patent number: 5121088
    Abstract: A frequency response equalizer, particularly for wideband networks, whose purpose is to reduce the influence of parasitic capacitances on the frequency behavior, includes the series arrangement of a first coil, a capacitor, a resistor and a second coil, in parallel with a series resistor, in which series arrangement the coils constitute a bifilarly wound transformer. The transformer includes two main inductances and two leakage sub-inductances, in series with the resistor and the capacitor, being arranged in parallel with the series resistor as an active series resonant circuit.
    Type: Grant
    Filed: January 18, 1991
    Date of Patent: June 9, 1992
    Assignee: U.S. Philips Corporation
    Inventor: Werner Heinlein
  • Patent number: 5115105
    Abstract: An arrangement for shielding a date bus coupler includes an overbraided shield electrically connected to each of the outer braids of the bus cables coupled by the coupler. The overbraided shield prevents shielding discontinuities at the terminations of the cables to the coupler.
    Type: Grant
    Filed: February 21, 1990
    Date of Patent: May 19, 1992
    Assignee: Amphenol Corporation
    Inventors: David O. Gallusser, James B. LeBaron
  • Patent number: 5093639
    Abstract: An electromagnetic stripline coupler apparatus having a pair of coupler units which are separated by a conductive ground plane with a slot in it that is aligned to pass signal energy between the coupler units.
    Type: Grant
    Filed: September 20, 1990
    Date of Patent: March 3, 1992
    Assignee: The United States of America as represented by the Secretary of the Air Force
    Inventors: Peter R. Franchi, Nicholas P. Kernweis
  • Patent number: 5091703
    Abstract: An analog line connection circuit provides that the transmission voltage is not superimposed on the received voltage given a data transmission in duplex operation via a two-wire line. The line connection circuit is provided with an amplifier that comprises two symmetrical outputs, the first of these outputs being connected via a first ohmic connecting resistor to a first terminal of a first winding of a transformer and the second output being connected via a second ohmic connecting resistor to a second terminal of the first winding of the transformer. The transformer comprises a second winding connected to a transmission line. A series circuit of a first auxiliary resistor, a complex impedence and a second auxiliary resistor is connected between the outputs of the amplifier.
    Type: Grant
    Filed: November 19, 1990
    Date of Patent: February 25, 1992
    Assignee: Siemens Aktiengesellschaft
    Inventor: Heinrich Schenk
  • Patent number: 5087898
    Abstract: An integrated semiconductor active isolator circuit which includes a negative feedback amplifier having an active semiconductor amplifier element. The control terminal of the semiconductor amplifying element defines the output of the isolator circuit and a principal conduction electrode of the semiconductor amplifying element defines an input of the isolator circuit.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: February 11, 1992
    Assignee: U.S. Philips Corp.
    Inventors: Ramesh Pyndiah, Francis van den Bogaart