Patents Examined by Seung Ham
  • Patent number: 5323128
    Abstract: A small and thin plane type narrow-band dielectric filter to be used for a portable telephone and the like, includes a plurality of end short-circuited strip line resonators having a length of about quarter-wavelength formed parallel and closely to each other on a first dielectric substrate and directly magnetically coupled to each other. The thus formed strip line resonators are partially bonded to parallel plane capacitor electrodes formed on a second dielectric substrate in respective overlapping areas thereby electrically coupling the strip line resonators through the parallel plane capacitors, so that the inter-resonator coupling can be reduced due to the fact that it is achieved in combination with the magnetic coupling and the electrical coupling.
    Type: Grant
    Filed: April 21, 1992
    Date of Patent: June 21, 1994
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toshio Ishizaki, Mitsuhiro Fujita, Hikaru Ikeda, Takashi Fujino
  • Patent number: 5293141
    Abstract: In a dielectric filter according to the present invention, a depressed part is formed by removing a portion of an outer peripheral conductor on the open face side of each of a plurality of one-end face short-circuited type coaxial resonators or a portion of the outer peripheral conductor including a dielectric member. A dielectric substrate having a plurality of capacitance forming electrodes for forming antiresonance capacitances between the electrodes and inner peripheral conductors of the coaxial resonators formed thereon is mounted on the depressed part, and a reactance element for coupling the capacitance forming electrodes is provided on the dielectric substrate.
    Type: Grant
    Filed: March 18, 1992
    Date of Patent: March 8, 1994
    Assignee: Sanyo Electric Co., Ltd.
    Inventors: Yasumi Kobayashi, Kousuke Takeuchi, Kachio Ikeda, Kenichi Shibata, Kazuhiko Kuroki
  • Patent number: 5280452
    Abstract: A sensing circuit for a dynamic random access memory structure is disclosed having first and second bit lines, one of the bit lines being a reference bit line which is held at a precharge voltage when a sense amplifier in the sensing circuit is latched, the sense amplifier includes first and second nodes and first, second, third and fourth transistor devices, the first and second transistor devices form an N-device cross-coupled pair and the third and fourth transistor devices form a P-device cross-coupled pair. The first node is connected to the first bit line and to the second and fourth transistor devices, and the second node is connected to the first and third transistor devices. A first isolation transistor device is connected to the first bit line and a second isolation transistor device is connected to the second bit line. A first clock signal line is connected to the first isolation transistor device and a second clock signal line is connected to the second isolation transistor device.
    Type: Grant
    Filed: July 12, 1991
    Date of Patent: January 18, 1994
    Assignee: International Business Machines Corporation
    Inventors: Sang H. Dhong, Lewis M. Terman
  • Patent number: 5278797
    Abstract: A semiconductor memory device, having cells respectively therein given information through rewriting, i.e., a refreshing operation, capable of performing non-periodic refreshing operations is disclosed. The semiconductor memory element internally includes a refresh request signal generator having a reference memory cell 51 connected to a word line in the memory device. The refresh request signal generator 100A generates refresh request signals only at that moment of erasing of information stored in the memory cell. The outputted refresh request signals cause refresh signals to transfer to the memory cell. Thus, non-periodic refreshing operations can be performed, thereby reducing the power consumption, and increasing the number of data input/output work.
    Type: Grant
    Filed: July 5, 1991
    Date of Patent: January 11, 1994
    Assignee: SamSung Electronics, Co. Ltd.
    Inventors: Jun-Young Jeon, Dae-Je Jin
  • Patent number: 5278528
    Abstract: An inexpensive and lightweight air insulated high frequency filter can be made utilizing a radio device's frame and a printed board (15) intended for electrical circuits, so that during manufacture of the printed board (15) it is machined so that several side by side finger-like projecting tongues (14.sub.1, 14.sub.2, 14.sub.3, 14.sub.4) are formed, which are entirely coated with electrically conducting material. Thereafter the printed board, on which electrical and mechanical components intended for it are mounted, is placed in the radio device's crate-like frame made of conducting material and possibly provided with partition walls (18, 19), and on which also cover parts are fastened so that the tongues will be parallel with them and located between them, whereby the tongues, the enclosing cover parts and the frame wall parts form a filter structure.
    Type: Grant
    Filed: March 31, 1992
    Date of Patent: January 11, 1994
    Assignee: Lk-Products OY
    Inventor: Aimo Turunen
  • Patent number: 5274346
    Abstract: A case has parts storage openings through a top plane. Terminals protrude above the plane and extend downward through the case to a bottom plane, where they are bent to conform to the bottom plane. Interconnections of the terminals in the bottom plane provide the wiring pattern necessary for the creation of an LC filter. LC combination parts are made using a coil wound on a coil support with a capacitor secured to the top surface of the coil support. The coil part of the LC combination parts are inserted into the parts storage openings of the case, to secure the coils rigidly in place. The coils and capacitors are affixed to the terminals above the top plane. The resulting rigid support of the LC combination units provides stable and accurate filter characteristic in a compact package. The interconnections of the terminals in the bottom plane permits observation of the connections to permit manual inspection or the use of pattern recognition hardware and software for robotic sorting and assembly.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: December 28, 1993
    Assignee: TDK Corporation
    Inventors: Toshio Izu, Kazuo Sato, Shigeyuki Doi, Hisashi Osada
  • Patent number: 5274347
    Abstract: A coaxial fitting comprises, a metallic tubular ferrule having a forward portion with knurling thereon and a rearward portion with external threads thereon by which such fitting is coupleable to a coaxial cable, the fitting also comprising an inner metallic rod conductor extending in the ferrule in concentric radially spaced relation therewith, and a dielectric plug disposed in the ferrule radially in contact with the ferrule and inner conductor to maintain them in fixed relation, the plug being longitudinally in contact with an inwardly projecting internal annular shoulder in the ferrule. The knurled portion of the fitting is adapted to be press fitted into a bore formed in the housing of a microwave device to provide a port for microwaves supplied to or from such device. The metallic parts of the fitting interiorly comprise copper and have precious metal platings thereon to reduce microwave resistance losses.
    Type: Grant
    Filed: August 11, 1992
    Date of Patent: December 28, 1993
    Assignee: AT&T Bell Laboratories
    Inventor: Omar J. Bobadilla
  • Patent number: 5274598
    Abstract: A semiconductor memory provided with improved sense amplifier-bit line arrangement which is suitable for a high-speed and high-sensitivity read operation. The memory comprises a main bit line pair, a main sense amplifier, a plurality of sub-bit line pairs and a plurality of sub-sense amplifiers in each column. Each of the sub-sense amplifiers includes a pair of output nodes coupled to the main bit line pair and a pair of input nodes coupled to one of the sub-bit line pairs. A pair of switch elements are inserted between the main bit line pair and each one of the sub-bit line pairs for selectively feeding an output of the main sense amplifier back to one of the sub-bit line pair selected.
    Type: Grant
    Filed: June 17, 1991
    Date of Patent: December 28, 1993
    Assignee: NEC Corporation
    Inventors: Takeo Fujii, Toshio Komuro
  • Patent number: 5270671
    Abstract: A negative slope phase skewer for use between radiating elements of series fed antenna array. The phase skewer has a four part coupler having two segments lying parallel to one another, each segment being a near and a far branch. The two near branches connect to the transmission line, while the far branches are at some distance from the transmission line. A series of spaced apart, progressively longer, high impedance open circuited stubs extends outward perpendicularly from each far branch. Two conductive connections connect the two segments between the transmission line and the stubs. Each stub is designed to be one quarter wavelength long of an average frequency in a band region of an operating band width, and are spaced apart by a quarter wavelength of the midpoint of the operating band.
    Type: Grant
    Filed: August 7, 1992
    Date of Patent: December 14, 1993
    Assignee: Westinghouse Electric Corp.
    Inventor: Timothy G. Waterman
  • Patent number: 5268659
    Abstract: Dual-mode resonators are coupled together to form a highly selective bandpass filter by means of a short section of waveguide. The short sections have cutoff frequencies beyond the passband of the filter. The coupling is adjustable over a wide range by means of adjustable screws. The coupling means is applicable to both empty cavities and dielectric-resonator-loaded cavities.
    Type: Grant
    Filed: April 29, 1991
    Date of Patent: December 7, 1993
    Assignee: University of Maryland
    Inventors: Kawthar A. Zaki, Seng-Woon Chen
  • Patent number: 5266911
    Abstract: A multiplexing system combines a plurality of electromagnetic signals to propagate along a common path, preferably a square waveguide which can be connected to an antenna feed horn of square cross section which can support both circularly and linearly polarized electromagnetic waves. The system is operative with a plurality of sets of signal channels including a first set of A-channel signals and a second set of B-channel signals. A circular polarizer connects with a first end of the waveguide. All of the A-channel signals are fed into an input port of the polarizer. The B-channel signals are coupled into the waveguide by a plurality of couplers located at positions arranged serially along the waveguide, individual one of the couplers operating at different ones of the B-channel frequencies for selectively coupling respective ones of said B-channel signals into the waveguide to propagate toward the second end of the waveguide.
    Type: Grant
    Filed: October 14, 1992
    Date of Patent: November 30, 1993
    Assignee: Hughes Aircraft Company
    Inventors: Robert C. Perpall, Ross Stramler, Joe Hall
  • Patent number: 5256990
    Abstract: A precision, waveguide-configured, bandstop filter comprises a substrate formed of a conductive material capable of being die cast. To facilitate manufacture and assembly, the substrate is preferably formed as a pair of symmetrically shaped substrate halves which, when mated together, define an interior filter structure that performs the required bandstop filter function. Each substrate half is configured to have a generally longitudinal slot that extends from a planar mating surface and effectively forms one half of an interior longitudinal waveguide section through the filter. Transverse to and located at spaced apart locations along the longitudinal slot are a plurality of channels, which define parallel conductive surface webs that extend from opposite sidewalls of the longitudinal slot. The channels serve as distributed, diametrically opposed pairs of lumped parameter tuning elements of the bandstop filter. A first end of each web forms a portion of a conductive sidewall of the longitudinal slot.
    Type: Grant
    Filed: May 8, 1992
    Date of Patent: October 26, 1993
    Assignee: Skydata, Inc.
    Inventor: Lock R. Young
  • Patent number: 5254963
    Abstract: The present invention is directed to reducing the number of components required to minimize intermodulation distortion within the wide transmission frequency band used by a satellite communications repeater system. In particular, at least two TM.sub.010 mode cavity is cascaded to a plurality of TE.sub.113 mode cavities to form a narrow band-pass, wide band-stop filter for receiving and outputting channel signals to the multiplexer manifold of a satellite repeater. The filter thus constructed realizes the narrow band-pass response required in microwave communications, while eliminating the spurious resonance frequencies normally eliminated by additional filter components. In this manner, the size and weight considerations of the satellite system are improved without loss in performance.
    Type: Grant
    Filed: September 25, 1991
    Date of Patent: October 19, 1993
    Assignee: COMSAT
    Inventors: Rene R. Bonetti, Albert E. Williams
  • Patent number: 5253206
    Abstract: A NAND cell type electrically erasable programmable read-only memory has NAND cell units. Each NAND cell unit has a series array of floating gate type metaloxide semiconductor field effect transistors as memory cell transistors. The first-stage memory cell transistor is connected at its gate to a corresponding bit line via a first select transistor The last-stage memory cell transistor is connected at its source to a common source line by means of a second select transistor. The common source line is connected with a test circuit to be used for measuring the distribution of threshold values of the memory cell transistors in the erasing state. The test circuit temporarily applies the common source line with a positive bias voltage of a predetermined potential level so that the potential of the control gate of a selected memory cell transistor is set at to 0 volt. As a result, the threshold value of the EEPROM in the erasing state can be measured without using any negative potential.
    Type: Grant
    Filed: March 28, 1991
    Date of Patent: October 12, 1993
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiyuki Tanaka, Masaki Momodomi, Fujio Masuoka
  • Patent number: 5252934
    Abstract: A signal delay assembly for a high power linear amplifier, using feedforward circuitry to reduce distortion, comprises an interdigital delay line unit with included directional couplers. The structure of the interdigital delay line is substantially in a parallelepiped housing. A co-axial connector constructed as an integral part of the delay unit is used for signal connection to the amplifier.
    Type: Grant
    Filed: August 25, 1992
    Date of Patent: October 12, 1993
    Assignee: AT&T Bell Laboratories
    Inventor: Robert E. Myer
  • Patent number: 5250916
    Abstract: A filter duplexer, such as a filter duplexer for a radio transceiver, of minimum dimensions is disclosed. A first filter portion of the duplexer filter includes resonators of a first geometric configuration, and a second filter circuit portion of the duplexer filter comprises resonators of a second geometric configuration. The geometric configuration of the two filter circuit portions are dissimilar such that relative characteristic admittances of the resonators of the respective filter circuit portions are dissimilar. Because the resonators of the two filter circuit portions are of dissimilar electrical characteristics, a desired frequency response of the duplexer filter may be obtained with similar resonator loading capacitances.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: October 5, 1993
    Assignee: Motorola, Inc.
    Inventor: Zdravko M. Zakman
  • Patent number: 5251179
    Abstract: An electrical product uses a small battery, which is permanently soldered into the product, to protect certain critical circuits such as volatile memory when primary power is removed. The life of such a battery is extended by disabling it during the time interval between factory testing and first use by a customer so that it does not drain during transportation and storage. During factory testing, instructions stored in volatile memory are delivered to a microprocessor that cause it to generate a unique signal that resets a switch and thereby disables the battery. These instructions are down-loaded into the volatile memory and executed as part of the final factory test procedure. When the primary power source is removed from the product following factory test, these instructions are lost (erased) because the battery is disabled at this time. The microprocessor is arranged to set the switch, and thereby enable the battery, each time primary power is subsequently applied or removed from the product.
    Type: Grant
    Filed: March 29, 1991
    Date of Patent: October 5, 1993
    Assignee: AT&T Bell Laboratories
    Inventor: Brian A. Wittman
  • Patent number: 5250915
    Abstract: A laminate type LC element includes a laminate defined by a plurality of stacked insulating layers. A first sheet-like conductor is formed between each pair of adjacent insulating layers to continuously wind and extend from between the pair of adjacent insulating layers to between another pair of adjacent insulating layers, the first conductor forming a coil having a preselected number of turns. A second sheet-like conductor is formed between each pair of adjacent insulating layers to continuously wind and extend from between the pair of adjacent insulating layers to between another adjacent pair of adjacent insulating layers, the second conductor being disposed in the face-to-face relationship relative to the first conductor through the insulating layers. The LC element has an increased capacitance and can reliably remove any external noise.
    Type: Grant
    Filed: February 19, 1992
    Date of Patent: October 5, 1993
    Assignee: Takeshi Ikeda
    Inventors: Takeshi Ikeda, Akira Okamoto
  • Patent number: 5251172
    Abstract: In a DRAM formed of MOS FETs, respectively different values of substrate bias voltage are applied to transistors of different types of circuit in accordance with the circuit functions, to thereby enable the threshold voltage of the transistors of the sense amplifiers to be brought close to zero, thereby reducing the bit line amplification delay, while maintaining sufficiently high values of threshold voltage for other circuits.
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: October 5, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Hiroyuki Yamauchi
  • Patent number: 5248949
    Abstract: A flat type dielectric filter comprises a substantially U-shaped strip line formed such that each center frequency of spurious output deviates from each odd number frequency times the center frequency of the dielectric filter. That is, it comprises a first portion so curved to form an open loop and two second portions formed to have a larger width than the first portion, each of the second portions being provided to an end of the first portion such that each extends in the opposite direction to the other. In this filter, input/output electrodes confronting ends of U-shaped strip line can be formed on a different layer from the layer where the resonator is formed in order to reduce its size. Reduction of size can be obtained by vertically folding the U-shaped strip line extending horizontally. Terminals of this filter formed on the side surface have a first layer formed on the side surface and a second layer formed on the first layer.
    Type: Grant
    Filed: March 12, 1992
    Date of Patent: September 28, 1993
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuhiro Eguchi, Fumio Fukushima, Koji Nishimura, Katsumi Sasaki, Takehiko Yoneda, Hiromitsu Taki