Rc Or Rl Type Patents (Class 333/172)
  • Patent number: 5929699
    Abstract: An active RC integrator filter with finite operational amplifier bandwidth can be compensated by biasing the operational amplifier input stage such that its transconductance becomes a function of the resistance. Thereafter, by inserting another resistance of the same material in series with the integrating capacitor, a zero results in the overall transfer function of the filter according to the present invention. In this manner, the passband peaking of the active RC integrator filter resulting from the integrator phase shift can be avoided.
    Type: Grant
    Filed: December 15, 1997
    Date of Patent: July 27, 1999
    Assignee: National Semiconductor Corporation
    Inventor: Laurence Douglas Lewicki
  • Patent number: 5914633
    Abstract: A tuning circuit for generating a digital code to be used to calibrate a capacitor array of the type used in active RC filters is comprised of a single-slope A/D converter with fixed reference voltages as inputs and an output value which is dependent on the RC product of a resistor and capacitor within the converter. A decoder converts the RC product as measured by the A/D converter into a digital code which, when applied to the appropriate capacitor array, sets the array capacitance to compensate for the difference between the measured RC product and the nominal design value.
    Type: Grant
    Filed: August 8, 1997
    Date of Patent: June 22, 1999
    Assignee: Lucent Technologies Inc.
    Inventors: Vittorio Comino, Dima David Shulman, Susan Jeanne Walker
  • Patent number: 5907242
    Abstract: A balanced bandpass preamplifier assembly (23) is disclosed for use in a locator (10) for locating a beacon transmitter (18) housed within an underground boring device (12). The bandpass preamplifier assembly (23) includes a balanced bandpass filter (28) of the Butterworth type with second order filter characteristics. The preamplifier assembly (23) provides reception of beacon frequencies at two distinct frequencies, preferably 29.430 KHz and 32.768 KHz. The antenna (14) of the . locator (10) forms the series inductance in the bandpass filter (28).
    Type: Grant
    Filed: September 20, 1996
    Date of Patent: May 25, 1999
    Assignee: The Charles Machine Works, Inc.
    Inventor: Michael F. Gard
  • Patent number: 5889445
    Abstract: Composite RC devices are described that provide predetermined impedance properties in a package similar to multilayer ceramic capacitors of the prior art. The RC devices include a plurality of first and second ceramic layers interleaved to form a stack. The ceramic layers each include a suitable electrode structure of opposite polarity forming the equivalent of multiple two-plate capacitors. One or more resistors are embedded in the device body and are selectively connected to the capacitor structure. In some presently preferred embodiments, multiple parallel resistors are provided, such as on each electrical side of the capacitor structure.
    Type: Grant
    Filed: July 22, 1997
    Date of Patent: March 30, 1999
    Assignee: AVX Corporation
    Inventors: Andrew P. Ritter, John L. Galvagni
  • Patent number: 5872466
    Abstract: A matched filter with reduced electric power consumption is disclosed. The matched filter circuit power consumption is reduced by stopping the electric power supply to an unnecessary circuit since input signal is partially sampled just after an acquisition. Since the spreading code is 1 bit data string, the input signal sampled and held is branched out into the signal groups "1" and "-1" by a multiplexer. The signals in each groups are added in parallel by a capacitive coupling, and the electric power is supplied in the circuit intermittently.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: February 16, 1999
    Assignees: Yozan Inc., Sharp Kabushiki Kaisha
    Inventors: Guoliang Shou, Changming Zhou, Makoto Yamamoto, Sunao Takatori
  • Patent number: 5864185
    Abstract: A passive filter device for a capacitor in series with a substantially inductive transmission line of an electric transmission system is disclosed. The passive filter device comprises a double-loop RCL filter in parallel with the series capacitor. At power frequency, the filter device allows the power frequency current to pass through the series capacitor with minimum power losses. At sub-synchronous resonance frequencies, the passive filter device provides bypassing of the series capacitor with maximum selectivity of the RCL filter.
    Type: Grant
    Filed: March 28, 1996
    Date of Patent: January 26, 1999
    Assignee: General Electric Company
    Inventors: Wendell Neugebauer, Stanley A. Miske, Jr., Satoru Ihara
  • Patent number: 5864256
    Abstract: A description is given of a circuit arrangement comprisinga filter quadripole having two output terminals anda voltage follower circuit having two terminals, said terminals having identical electric potentials when the voltage follower circuit is in its turned-on state, each of the terminals of the voltage follower circuit being connected to one of the output terminals of the filter quadripole respectively, and the voltage follower circuit only being in its turned-on state during the turn-on time interval of the circuit arrangement. This circuit arrangement is suitable for a receiver circuit, more particularly, for a pager and has a very brief turn-on time.
    Type: Grant
    Filed: March 6, 1997
    Date of Patent: January 26, 1999
    Assignee: U.S. Philips Corporation
    Inventors: Burkhard Dick, Manfred Biehl, Winfried Jansen, Bernd Pille, Norbert Wirges
  • Patent number: 5861744
    Abstract: An input filter for a vehicle anti-lock brake system control module has a filter section for attenuating input signals having mid-range frequencies.
    Type: Grant
    Filed: February 10, 1997
    Date of Patent: January 19, 1999
    Assignee: Kelsey-Hayes Company
    Inventor: Kenneth C. Earl
  • Patent number: 5861783
    Abstract: The amplification of crosstalk between two isolated circuits due to a resonant condition between the two circuits is reduced by coupling the electrical grounds associated with the circuits with a series Resistor-Capacitor network.
    Type: Grant
    Filed: August 1, 1997
    Date of Patent: January 19, 1999
    Assignee: Lucent Technologies Inc.
    Inventor: Joseph Peter Savicki
  • Patent number: 5841822
    Abstract: A communication receiver (600) utilizes a band-pass sigma-delta converter (100) for receiving a radio signal. The band-pass sigma-delta converter (100) includes a comparator (106) coupled to an adder-filter (101) for making a comparison between a predetermined reference level (110) and an intermediate signal (125), and for generating a comparison result signal (114) responsive to the comparison. A storage element (108) is used for storing the comparison result signal (114) for a predetermined delay period, thereby producing a clocked output signal (118). The adder-filter (101) is coupled to an analog signal (103) and to the clocked output signal (118) for subtracting the clocked output signal (118) from the analog signal (103) to produce a difference signal (120) that is filtered by a commutating filter (400) for generating the intermediate signal (125) responsive to the difference signal (120).
    Type: Grant
    Filed: December 1, 1997
    Date of Patent: November 24, 1998
    Assignee: Motorola, Inc.
    Inventors: James Gregory Mittel, Raymond Louis Barrett, Jr., Walter Davis
  • Patent number: 5821832
    Abstract: A signal transmission circuit for transmitting signals having a wide frequency spectrum over a cable. The circuit includes an isolating transformer having a high pass filtering function; a low-pass filter, the input of the low pass filter being common with the input of the high pass filter; and means for summing the output voltages of the low-pass filter and the high-pass filter.
    Type: Grant
    Filed: November 26, 1996
    Date of Patent: October 13, 1998
    Assignee: SGS-Thomson Microelectronics S.A.
    Inventor: Jean-Michel Moreau
  • Patent number: 5815051
    Abstract: Differential filters for removing both normal-mode and common-mode noises are provided. A first-order differential low pass filter is composed of a first resistor connected between a first input terminal and a first output terminal, a second resistor having the same resistance value as the first resistor and connected between a second input terminal and a second output terminal, a first capacitor connected between the first output terminal and a reference potential, a second capacitor having the same capacitance value as the first capacitor and connected between the second output terminal and the reference potential, and a third capacitor connected between the first output terminal and the second output terminal.
    Type: Grant
    Filed: September 25, 1996
    Date of Patent: September 29, 1998
    Assignee: Burr-Brown Corporation
    Inventors: Toshihiko Hamasaki, Hitoshi Terasawa, Toshio Murota
  • Patent number: 5789999
    Abstract: A lossy capacitive circuit element, or DC scrubber, is printed on a circuit substrate and absorptively filters high frequency signals in circuit modules. A top conductor of the DC scrubber is separated from a ground conductor by a layer of high dielectric material. A resistive layer, positioned either above or below the top conductor absorbs high frequency signals applied to the top conductor while the dielectric layer shunts the signals to the ground conductor. Alternatively, a pair of DC scrubbers are stacked vertically to configure the lossy capacitive structures in parallel. Signal isolation provided by the DC scrubber and the stacked DC scrubber enables inexpensive DC interfaces to be used in the circuit modules.
    Type: Grant
    Filed: November 1, 1996
    Date of Patent: August 4, 1998
    Assignee: Hewlett-Packard Company
    Inventors: Ron Barnett, John F. Casey
  • Patent number: 5781082
    Abstract: In an R-C filter for preventing a noise signal from entering a power supply system through its output circuit, a circuit component acting as a resistive element for the filter is connected in series with the output circuit and a capacitive element is connected between one portion of the circuit component and ground to form an R-C type filter. A wiring member, a printed wiring foil, a through-hole member, a semiconductor device or other such circuit component can be used, as the circuit component acting as the resistive element for constituting the R-C type filter.
    Type: Grant
    Filed: August 30, 1995
    Date of Patent: July 14, 1998
    Assignee: Zexel Corporation
    Inventors: Yoshihide Gunji, Hideaki Matsuzaki, Hiroshi Ohsawa
  • Patent number: 5767757
    Abstract: An integrated circuit R/C network and method for providing a selectively variable impedance in which a capacitor has a high resistivity semiconductor plate with a low resistivity body contact region therein, the contact region for providing a variable resistance in series with the capacitor, and in which a control terminal is connected to the plate for selectively applying a control voltage thereto which varies the series resistance to thereby vary the impedance of the network.
    Type: Grant
    Filed: July 29, 1996
    Date of Patent: June 16, 1998
    Assignee: Harris Corporation
    Inventor: John S. Prentice
  • Patent number: 5760456
    Abstract: A planar inductor structure with improved Q compatible with typical integrated circuit fabrication. The structure includes a spiral inductor with a conductive plane between the resistive substrate of the integrated circuit and the spiral inductor which reduces the power loss of the inductor. A pattern of segments may be formed in the conductive material of conductive plane to prevent eddy currents from flowing through the conductive plane and reducing the inductance of the spiral inductor. The Q of the inductor can be enhanced by optimizing the pattern in which the segmented conductive plane is formed. The segmented conductive plane may be fabricated out of metal, polysilicon or a heavily-doped region of the substrate.
    Type: Grant
    Filed: December 21, 1995
    Date of Patent: June 2, 1998
    Inventors: Andrew Z. Grzegorek, William J. McFarland
  • Patent number: 5760641
    Abstract: A controllable filter arrangement comprises a filter network for filtering an input signal of the filter arrangement, and a transistor, the transistor being configured as a voltage-follower having a controllable current source in its output circuit for providing a controllable DC transistor output current, an output terminal of the voltage-follower being connected to the filter network such that a cut-off frequency of the filter can be controlled by variation of the DC current supplied by the current source. The filter network may be a single-pole RC network and the output of the follower may be connected to an additional capacitor (or resistor) of the network which is coupled to the junction of the existing capacitor and resistor.
    Type: Grant
    Filed: February 21, 1996
    Date of Patent: June 2, 1998
    Assignee: Plessey Semiconductors Limited
    Inventors: Marcus Richard Granger-Jones, Colin Leslie Perry
  • Patent number: 5760662
    Abstract: A Quarter Size Small Outline Packages (QSOP) integrated resistor/capacitor network. The QSOP integrated resistor/capacitor network includes resistor/capacitor filters implemented in a QSOP package in integrated form. In one embodiment, the QSOP integrated resistor/capacitor network includes at least six ground pins for coupling capacitors of the resistor/capacitor filters with a common ground to maximize the attenuation of ultra-high frequency signals filtered through the resistor/capacitor filters.
    Type: Grant
    Filed: February 28, 1996
    Date of Patent: June 2, 1998
    Assignee: California Micro Devices Corporation
    Inventors: Jeffrey Clifford Kalb, Peruvamba Hariharan, Anguel Svilenov Brankov
  • Patent number: 5760642
    Abstract: A filter circuit using junction capacitors of semiconductors of the present invention prevents the distortion of signal waveforms and is not affected by parasitic capacitors. The filter circuit includes a resistor whose first terminal is connected to an input terminal and whose second terminal is connected to an output terminal. A first junction capacitor is connected between a control voltage supply terminal and an output terminal and a second junction capacitor is connected between the output terminal and ground. An alternate embodiment of the filter circuit includes a pnp transistor, whose emitter is connected to the direct current power supply via a resistor, whose collector is grounded, and whose base is connected to the output terminal.
    Type: Grant
    Filed: October 16, 1996
    Date of Patent: June 2, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toshiro Yada
  • Patent number: 5751184
    Abstract: A low electric power consumption filter circuit includes an amplifying portion including an odd number of serial MOS inverters. A grounded capacitance is connected between an output of the amplifying portion and ground. A pair of balancing resistances connect an output of the MOS inverter to a supply voltage and ground at a previous stage of the last MOS inverter. A feedback impedance connects an output of the amplifying portion to its input. An input impedance is connected to the input of the amplifying portion.
    Type: Grant
    Filed: October 17, 1996
    Date of Patent: May 12, 1998
    Assignees: Yozan Inc., Sharp Kabushiki Kaisha
    Inventors: Guoliang Shou, Makoto Yamamoto, Sunao Takatori
  • Patent number: 5739732
    Abstract: An alternating current (AC) spike absorption circuit employs a pair of back-to back parallel high-speed ultra-soft recovery diodes with unique RFI prevention characteristics. Further high frequency noise suppression is achieved by using a high voltage parallel-connected capacitor and a plurality of series-connected parallel ceramic-type resistors which are formed by resistors having coil windings providing an equivalent circuit of parallel resistance and inductance. The inductance provides ultra high frequency rejection and the resistance provides damping of any ringing oscillation. A surrounding ceramic material casing of the ceramic-type resistors resists the transmission of radio frequency energy.
    Type: Grant
    Filed: January 23, 1996
    Date of Patent: April 14, 1998
    Inventor: Page Huie Man Kit
  • Patent number: 5731747
    Abstract: An electronic component with a substrate (1, 31) of which a surface (4, 34) is provided with a thin-film structure with passive elements (5, 35), with a resistor (6, 36) formed in a layer of resistor material (7, 37), and with a capacitor having a lower electrode (9, 39) formed in an electrode layer (10, 40) provided on the surface, a dielectric (11, 41) formed by a layer of insulating material (12, 41) provided on the lower electrode, and an upper electrode (13, 43) formed in an electrode layer (14, 44) provided on the dielectric. One of the electrodes (9, 43) of the capacitor (8, 38) is formed in an electrode layer (10, 44) which is constructed as a dual layer (19-21, 49-51), of which the layer of resistor material (7, 37) in which also the resistor (6, 36) is formed constitutes a first partial layer (19, 49), on which a layer of conductive material (20, 55) is provided which constitutes the other, second partial layer (21, 51).
    Type: Grant
    Filed: February 23, 1996
    Date of Patent: March 24, 1998
    Assignee: U.S. Philips Corporation
    Inventors: Gerjan F. A. Van De Walle, Edward W. A. Young
  • Patent number: 5693988
    Abstract: A filtering device, connected between an electrical power supply source and a load, comprises an active filter connected to the source and to the load, and a passive filter connected to the load. A voltage, generated between two terminals of the active filter, is monitored by first and second circuits. The first circuit receives a signal representative of a current, and monitors the voltage according to the signal representative of the current on input of the filtering device and to a first coefficient. The second circuit receives a signal representative of a voltage, and monitors the voltage according to the voltage signal and to a second coefficient. The first and second coefficients have values variable according to the frequency.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: December 2, 1997
    Assignees: Schneider Electric SA, Electricite de France
    Inventors: Eric Bettega, Miaoxin Wang
  • Patent number: 5686861
    Abstract: A filter circuit that consumes very little electric power. The active filter is a linear inverter constructed by 1) an inverting amplifying portion composed of an odd number of MOS inverters serially connected, 2) a grounded capacitance connected between an output of the inverting amplifying portion and ground, 3) a balancing resistance having a pair of resistances for connecting an output of one of the MOS inverters, other than the last MOS inverter, to the supply voltage and the ground, respectively, and 4) a feedback impedance for connecting the output and input of the inverting amplifying portion. A coupling capacitance is connected to the input of the linear inverter and a plurality of filter circuits are connected to an input of the coupling capacitance.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: November 11, 1997
    Assignees: Yozan Inc., Sharp Kabushiki Kaisha
    Inventors: Guoliang Shou, Sunao Takatori, Makoto Yamamoto
  • Patent number: 5670917
    Abstract: The present invention is directed to an AC termination which includes a substrate having first and second surfaces. A resistor is mounted on the first surface of the substrate. An input termination is at one end of the resistor. At least one plate of a capacitor is on the substrate and is electrically connected in series with the other end of the resistor. In one form of the termination, the capacitor is a metal film on the substrate extending from the other end of the resistor to and across the second surface of the substrate to form one electrode of the capacitor. A dielectric layer is over the metal film and another metal film extends over the dielectric layer to form the other electrode of the capacitor and the output termination of the termination. In another form of the termination, the capacitor is formed on a cover plate which extends over the first surface of the substrate and is electrically connected between the resistor and an output termination.
    Type: Grant
    Filed: September 12, 1996
    Date of Patent: September 23, 1997
    Assignee: EMC Technology, Inc.
    Inventor: Joseph B. Mazzochette
  • Patent number: 5629655
    Abstract: A low pass filter including a number of different filter sections each having two input and two output terminals as well as a common terminal. Each filter section includes first and second resistors connected in series between respective first and second input terminals and first and second output terminals. Each of the resistors is formed by depositing a pattern of resistive material over a conducting plate with an intervening dielectric layer to provide a distributed capacitance between the resistive pattern and the conductive plate. Resistive elements are connected between at least one combination of (1) each of the conducting plates to the common terminal and (2) the conducting plates. A resistor is connected between the output terminals of at least one of the filter sections. The filter sections are cascade connected such that the output terminals in one section are connected to the input terminals of the next.
    Type: Grant
    Filed: February 23, 1996
    Date of Patent: May 13, 1997
    Assignee: Ericsson Inc.
    Inventor: Paul W. Dent
  • Patent number: 5608756
    Abstract: The invention relates to a device identifying traffic on a cable. The different types of traffic are characterized by different levels and frequency ranges. The device includes a limiter connected to the paired cable and delivering an output signal having substantially constant amplitude And a frequency corresponding to the strongest frequency component of the input signal. The limiter may be constructed of inverters coupled as an amplifier or of an amplifier having a Schmitt trigger. The limiter is connected to a frequency indicator indicating what frequency ranges within which the strongest frequency component lies. The frequency indicator may consist of monostables or counters and decoders. The decoder interprets the output signal of the counter and may be constructed of a fixed gate network or of a programmable memory. The output signal of the frequency indicator is connected to an indicator indicating the frequency range in question, e.g. by means of flashing light-emitting diodes.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: March 4, 1997
    Assignee: Televerket
    Inventors: Alexander Latour-Henner, Bjorn Isheden
  • Patent number: 5603306
    Abstract: An ignition coaxial cable includes at least a braided layer of copper wires surrounding a central or inner conductor existing at a longitudinal center of the coaxial cable for shielding and grounding the interference caused by the high voltage carried by the cable, and an interference eliminating circuit having an inductor parallelly connected with a high-impedance resistor and connected in series with a low-impedance resistor to prevent the acute wave forms and to inhibit the surge waves caused by the high-tension voltage pulses delivered from the distributor to the plug, thereby eliminating the interference or electromagnetic interference caused by the high-tension cable and the plug of the car.
    Type: Grant
    Filed: February 3, 1995
    Date of Patent: February 18, 1997
    Inventor: Tsai-Ting Tai
  • Patent number: 5598131
    Abstract: The present invention is directed to an AC termination which includes a substrate having first and second surfaces. A resistor is mounted on the first surface of the substrate. An input termination is at one end of the resistor. At least one plate of a capacitor is on the substrate and is electrically connected in series with the other end of the resistor. In one form of the termination, the capacitor is a metal film on the substrate extending from the other end of the resistor to and across the second surface of the substrate to form one electrode of the capacitor. A dielectric layer is over the metal film and another metal film extends over the dielectric layer to form the other electrode of the capacitor and the output termination of the termination. In another form of the termination, the capacitor is formed on a cover plate which extends over the first surface of the substrate and is electrically connected between the resistor and an output termination.
    Type: Grant
    Filed: November 16, 1995
    Date of Patent: January 28, 1997
    Assignee: EMC Technology, Inc.
    Inventor: Joseph B. Mazzochette
  • Patent number: 5589440
    Abstract: High Tc superconducting limiters are designed to operate at two or more levels of input signals. In one waveguide embodiment, multiple half wavelength branch waveguide lines are connected to a main waveguide line. The half wavelength lines are terminated with tuned circuits of a capacitance, made of a ferroelectric material, and an inductance provided by a waveguide line. In another waveguide embodiment, the branch lines are terminated in tuned cavities each having a ferroelectric material. In a microstrip embodiment, multiple half wavelength branch ferroelectric lines of different impedances are connected to a main line. In a second microstrip line embodiment, tuned circuits, with differing L and C values, are connected to a main transmission line through a half a wavelength branch transmission line. The capacitance is made of a ferroelectric material. The conductor, deposited on the microstrip lines, and the waveguides are made of a single crystal high Tc superconductor.
    Type: Grant
    Filed: March 9, 1994
    Date of Patent: December 31, 1996
    Inventor: Satyendranath Das
  • Patent number: 5585330
    Abstract: A high-temperature superconductor (HT.sub.c S) in a microstrip configurat which is electrically related to a superconducting coupler and which is controlled by a heater disposed over the superconducting microstrip line. This limiter configuration is used in a series configuration with other circuitry and utilizes the low loss characteristics of the HT.sub.c S material and the wide bandwidth characteristics of microstrip. The structure itself is a five layer microstrip geometry which includes a normal metal ground plane; a dielectric substrate disposed on the metal ground plane; a superconducting microstrip transmission disposed on the substrate; a dielectric film layer disposed on the superconducting microstrip; and a heating element disposed on the dielectric film layer and over the superconducting microstrip.
    Type: Grant
    Filed: January 9, 1995
    Date of Patent: December 17, 1996
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Roland Cadotte, Jr., Richard W. Babbitt, Xiaoguang G. Sun
  • Patent number: 5561586
    Abstract: An electronic device which has, on a rectangular insulating substrate, an input electrode and an output electrode, grounding electrodes and a conductor for electrically connecting the input electrode and the output electrode. The input electrode and the output electrode are disposed on both ends of the substrate. The grounding electrodes are disposed on side surfaces of the substrate in the center, and the conductor is disposed on an upper surface of the substrate. The conductor is a conductor with a high conductivity, a resistor or a coil. A capacity is generated between the conductor and the grounding electrode. If the conductor is a resistor, an RC circuit is formed.
    Type: Grant
    Filed: March 3, 1995
    Date of Patent: October 1, 1996
    Assignee: Murata Manufacturing Co, Ltd.
    Inventors: Takashi Tomohiro, Hiromichi Tokuda
  • Patent number: 5541564
    Abstract: A hybrid R-C component for use in oscilloscope probes of the type having a resistive element disposed on a first surface of a substrate, and having a first conductive coating disposed on a second surface of the substrate, and having a dielectric layer disposed over the first conductive coating, a second conductive coating partially disposed over a first portion of the substrate and in contact with a first end of the resistive element and with a region of the second conductive coating being partially disposed over the dielectric layer and forming a first capacitor plate, a third conductive coating disposed over a second portion of the substrate and in contact with a second end of the resistive element and with a region of the third conductive coating being partially disposed over the dielectric layer and forming a second capacitor plate, whereby the first capacitor plate and a first area of the first conductive coating in conjunction with the dielectric layer form a first capacitor C1 and the second capacitor
    Type: Grant
    Filed: June 20, 1995
    Date of Patent: July 30, 1996
    Assignee: Tektronix, Inc.
    Inventors: Eugene J. Climer, Wayne D. Thomas
  • Patent number: 5528682
    Abstract: A method and circuit in which two filters connected to different inputs that do not operate at the same time share a common capacitor to thereby reduce the number of capacitors needed for the circuit. A filter that is connected to an input that is not operating may be selectively disabled by connecting a resistor form the disabled filter and the common capacitor to ground when the other input is being operated. The method and circuit find application in a telephone system in which a filter connected to a subscriber line interface circuit (SLIC) and a filter connected to a telephone system circuit that does not operate at the same time as the SLIC share a common capacitor.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: June 18, 1996
    Assignee: Harris Corporation
    Inventor: Gerald M. Cotreay
  • Patent number: 5523725
    Abstract: A signal-to-noise enhancer 10 includes a first 90 degree hybrid set 20. A first output end of the first 90 degree hybrid set 20 is connected to an input end of a limiter used a magnetostatic wave element 62a utilized the magnetostatic surface wave mode. Also, a second output end of the first 90 degree hybrid set 20 is connected to an input end of a filter used a magnetostatic wave element 62b similar to the magnetostatic wave element 62a in structure, via a resistor 32 as a first attenuator. Furthermore, an output end of the limiter is connected to a first input end of a second 90 degree hybrid set 40 via a resistor 52 as a second attenuator. Also, an output end of the filter is connected to a second input end of the second 90 degree hybrid set 40.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: June 4, 1996
    Assignees: Murata Manufacturing Co., Ltd., Nippon Hoso Kyokai
    Inventors: Youhei Ishikawa, Takekazu Okada, Satoru Shinmura, Fumio Kanaya, Shinichiro Ichiguchi, Toshihito Umegaki, Toshihiro Nomoto
  • Patent number: 5519581
    Abstract: A small toroidal inductor is mounted by inserting a high valued resistor or a ceramic coil form into the central hole of the toroid. The fine leads of the inductor are then soldered to the much stiffer leads of the part that has been inserted. These stiffer leads may be bent in any desired way, and will hold their shape. This makes insertion easier and is strong enough to withstand the necessary amounts of shock and vibration. The toroid may be glued or otherwise affixed with an adhesive to the resistor or coil form.
    Type: Grant
    Filed: October 21, 1994
    Date of Patent: May 21, 1996
    Assignee: Hewlett-Packard Company
    Inventor: Steven F. Liepe
  • Patent number: 5495387
    Abstract: A plurality of capacitor elements defined by first and second capacitor electrodes are formed in the interior of a laminated ceramic block, while a plurality of first terminal electrodes to be electrically connected to the first capacitor electrodes and a ground terminal electrode to be connected to the second capacitor electrodes in common are formed on one side surface of the block. A plurality of resistor films are formed on a major surface of the block, to be connected to the first terminal electrodes. A plurality of second terminal electrodes are formed on another side surface of the block, to be electrically connected to the resistor films. Another ground terminal electrode is formed on this side surface, to be connected to the second capacitor electrodes in common. Thus, an RC array being applicable to a high frequency filter array is integrated and miniaturized to cope with high density packaging, as well as to enable surface mounting.
    Type: Grant
    Filed: July 6, 1994
    Date of Patent: February 27, 1996
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Harufumi Mandai, Yoshikazu Chigodo, Kazuhiro Iida
  • Patent number: 5489871
    Abstract: A method and circuit for achieving reduced signal distortion in a filtered signal. The method involves connecting an input signal to a main path and a side chain path. The signal carried on the side chain path is then processed to generate a complementary signal which, when combined with the input signal carried by the main path, will produce a target output signal. The circuit includes a side chain processing stage, having a filter stage and a first subtraction stage, and a final processing stage. The input signal is carried on the side chain path to a filter path and a processing path. The signal carried on the filter path is filtered through the filter stage to generate a first filtered signal. The first filtered signal is then subtracted from the input signal on the processing path at the first subtraction stage to generate a complementary processed signal. The complementary processed signal is then subtracted from the input signal on the main path to generate the target output signal.
    Type: Grant
    Filed: April 29, 1994
    Date of Patent: February 6, 1996
    Assignee: Audio Products International Corp.
    Inventors: Ian Paisley, Stefan R. Hlibowicki
  • Patent number: 5483552
    Abstract: In an adaptive equalizing apparatus using quantized feedback, when the tap coefficients of a FIR filter are suddenly decreased due to a large noise input, or when the input signal level is suddenly lowered, the level of the input signal to the quantized feedback circuit becomes low, and the quantized feedback circuit malfunctions. Since the result of the quantized feedback circuit is utilized in the adaptive equalizing apparatus, the adaptive equalizing apparatus malfunctions, and cannot be restored to the normal operating state. To prevent the malfunction of the adaptive equalizing apparatus, as the first measure, limiters are inserted in the input lines of the tap coefficients of the FIR filter, the level of the signal entering the quantized feedback circuit is limited so as not to be lower than a specific value, thereby preventing the quantized feedback circuit from malfunctioning.
    Type: Grant
    Filed: October 27, 1993
    Date of Patent: January 9, 1996
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroaki Shimazaki, Haruo Ota
  • Patent number: 5466976
    Abstract: A time constant detecting circuit incorporated in an LSI detects variations of component values of resistors and capacitors in the LSI by detecting variations of a time constant. A pseudo-resistor is formed by a switched capacitor circuit and at least two switches which are alternately switched on and off in a period T to control a capacitor to be charged and discharged. With the operation of the capacitor having a capacitance C, there is formed a pseudo-resistor having a resistance R.sub.p =T/C. A predetermined DC voltage is divided by a series circuit of the pseudo-resistor and an ordinary resistor, and smoothed by a capacitor. The output voltage V.sub.out which has been smoothed and appears at the output terminal is uniquely defined by a time constant .tau.=1/RC, so that the variations of the time constant which are dependent on the resistors and capacitors in the LSI can be detected by a measurement of the output voltage V.sub.out.
    Type: Grant
    Filed: December 28, 1992
    Date of Patent: November 14, 1995
    Assignee: NEC Corporation
    Inventor: Masaki Ichihara
  • Patent number: 5450252
    Abstract: A hard disk drive includes a head for recording/reproducing data on a recording medium, a motor for moving the head on the recording medium, a motor driver for supplying a driving current to the motor, a data processing circuit for processing data reproduced from the head or record data given to the head, and a cable which has a current line connecting between the motor driver and the motor and a data line connecting between the data processing circuit and the head. The motor has been connected with a noise canceler comprising series-connected first and second filters in parallel with the motor. The connecting point of the first and the second filters of the noise canceler is grounded. A noise generated from the motor driver flows to a ground via the connecting point of the first and the second filters and is cancelled.
    Type: Grant
    Filed: February 16, 1994
    Date of Patent: September 12, 1995
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroyuki Kanda
  • Patent number: 5434535
    Abstract: An RC filter for low or very low frequency applications, comprising a resistor between the filter input and output, and an amplifier connected after the resistor and having an output fed back to the amplifier input through a capacitor. This simple design allows the known Miller Effect to be utilized to produce a filter having a high time constant while employing small-size components which occupy little space in integrated circuits.
    Type: Grant
    Filed: July 23, 1993
    Date of Patent: July 18, 1995
    Assignee: S.G.S. Thomson Microelectronics S.r.l.
    Inventors: Luciano Tomasini, Rinaldo Castello
  • Patent number: 5420553
    Abstract: A noise filter includes a plurality of resistance patterns arranged in parallel, and a ground pattern opposed to the resistance patterns via a dielectric substrate. Distribution capacitance is caused between the resistance patterns and the ground pattern. The function of the noise filter comes from the distribution capacitance and the resistance of the resistance patterns as the RC composite elements. The noise filters can be connected in plural. Noise can be eliminated without twisting the effective signal components in a compact noise filter.
    Type: Grant
    Filed: February 25, 1993
    Date of Patent: May 30, 1995
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yukio Sakamoto, Toshimi Kaneko
  • Patent number: 5408204
    Abstract: An amplitude limiter including an input power divider, first and second circuit branches each having an input end coupled to receive a split input signal and each being substantially identical electrically parallel-connected branches, each circuit branch being composed of a series connection of first and second conductor sections with the first and second conductor sections having respectively different lengths, and with the first and second conductor sections of each circuit branch being connected in anti-parallel, an absorber resistor connected between the two respective input ends of the circuit branches, and first and second rectifiers with each respective rectifier being connected between a connection point between the first and second conductor sections of each respective circuit branch and a ground conductor.
    Type: Grant
    Filed: October 6, 1993
    Date of Patent: April 18, 1995
    Assignee: Deutsche Aerospece AG
    Inventors: Heinz-Peter Feldle, Bernhard Schweizer
  • Patent number: 5408690
    Abstract: In an antenna supervising apparatus for supplying a multiplexed signal comprised of a plurality of carrier wave signals respectively outputted from a plurality of transmitters through a transmission line to an antenna, a directional coupler detects progressive signals of the multiplexed signal to the antenna and the reflected signals thereof from the antenna, and a band-pass filter respectively filters the progressive signal and the reflected signal of one carrier wave signal preselected among those of the detected multiplexed signal. Further, a detector respectively detects the filtered progressive signal and the filtered reflected signal of the one carrier wave signal, and a micro processing unit calculates a standing wave ratio with respect to the preselected one carrier wave signal based on the detected signals.
    Type: Grant
    Filed: March 11, 1994
    Date of Patent: April 18, 1995
    Assignee: Murata Mfg. Co., Ltd.
    Inventors: Youhei Ishikawa, Sadao Yamashita, Hidekazu Wada
  • Patent number: 5392456
    Abstract: A method of controlling the time constant of a filter for use in a radio receiver which receives a signal, transmitted from a transmitting station at a predetermined period, intermittently at the predetermined period and demodulates and delivers the received signal, a filter circuit having the time constant control function based on the method, and a radio receiver having the filter circuit. Preferably, the filter has its time constant switchable stepwise and specifically, parallel connection of capacitors or shortcircuiting of resistors is controlled by turning on/off switches.
    Type: Grant
    Filed: October 3, 1990
    Date of Patent: February 21, 1995
    Assignees: Hitachi, Ltd., Kokusai Electric Co., Ltd.
    Inventors: Isamu Mitomo, Nobuo Tsukamoto, Arata Nakagoshi, Jiroh Sakaguchi, Kazuo Yamakido, Hiroshi Noguchi, Atushi Hoshi
  • Patent number: 5357226
    Abstract: A noise filter 11 of the CR type in which electrodes 17a and 17b and electrodes 17d and 17e are formed on the outer surface of a collar portion 15 in a bobbin 12 composed of a dielectric body, recess portions 15c and 15d are respectively formed between the electrodes 17a and 17b and between the electrodes 17d and 17e, and resistance films 18a and 18b are respectively formed along the recess portions 15c and 15d. To form a noise filter of the LCR type, a coil 14 is formed on the bobbin 12 and connected to the electrodes 17b and 17d via electrodes 13a and 13b, respectively.
    Type: Grant
    Filed: May 19, 1993
    Date of Patent: October 18, 1994
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Takahiro Azuma
  • Patent number: 5345199
    Abstract: A passive RF limiting circuit device providing protection for receiver front ends and the like by utilizing PIN diodes acting as switching devices which transform a low-loss T-network attenuator circuit into a high-loss .pi.-network attenuator circuit under high power conditions.
    Type: Grant
    Filed: August 12, 1993
    Date of Patent: September 6, 1994
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Chance M. Glenn, Sr., Roger Kaul, David Sumner, Kisha N. Gwyn
  • Patent number: 5341114
    Abstract: Integrated circuit structure and processing is provided for a high power limiter including at least a first anti-parallel array of monolithically integrated Schottky diodes. In a further embodiment, integrated circuit structure and processing is provided for an MMIC, microwave and millimeter wave monolithic integrated circuit, including an amplifier and a high power limiter monolithically integrated on the same substrate.
    Type: Grant
    Filed: November 2, 1990
    Date of Patent: August 23, 1994
    Assignee: AIL Systems, Inc.
    Inventors: Joseph A. Calviello, John A. Pierro
  • Patent number: 5329261
    Abstract: The ferroelectric limiter utilizes the bias voltage dependent dielectric constant property of a ferroelectric material. A main transmission line having a length of two or more half wavelengths at the operating frequency is used. A branch line is connected at one half wavelength away from one end of the transmission line. The branch line presents a very high impedance on the main transmission line at a low level of signal. The branch line contains a ferroelectric material. As the signal level increases, the dielectric constant of the ferroelectric material in the branch line changes. This reduces the impedance presented by the branch line on the main transmission line reducing the impedance of the main transmission line and the resulting output of the limiter. As the signal level increases, the impedance presented by the branch line on the main transmission line becomes increasingly smaller, further reducing the output of the of the limiter. Two designs of the limiter are presented.
    Type: Grant
    Filed: May 27, 1993
    Date of Patent: July 12, 1994
    Inventor: Satyendranath Das