Patents Examined by Justin P. Bettendorf
  • Patent number: 6522220
    Abstract: A frequency variable filter in which both the frequency of an attenuation pole and the attenuation bandwidth can be varied. In the frequency variable filter, two serial resonance sections composed of resonators and resonance capacitors are electrically connected to each other via a capacitor. The respective resonator in each of the serial resonance sections is electrically connected in parallel with a corresponding serial circuit composed of a frequency shifting capacitor and a PIN diode. A coupling capacitor electrically connects the junctions defined respectively between the frequency shifting capacitor and the PIN diode in each of the serial circuits.
    Type: Grant
    Filed: April 19, 2001
    Date of Patent: February 18, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yasuo Yamada, Kikuo Tsunoda, Masayuki Atokawa, Hirofumi Miyamoto, Hajime Suemasa
  • Patent number: 6518851
    Abstract: A ferrite structure for non-reciprocal microwave device such as circulator/isolator. The structure includes one or more composite ferrite bodies, each having at least one region of a soft ferrite material and at least one region of a hard ferrite material, and at least two ferrous/ferrite plates. The ferrous/ferrite plates are attached to the composite ferrites so as to contribute to the completion of the magnetic loop via hard and soft ferrite portions of the composite ferrites. The soft and hard ferrite regions are magnetized in the opposite directions. The range of operation is selected to be between the resonant frequencies of soft and hard ferrite materials. With such setting the hard and soft ferrite regions provide the circulation in the same direction. As compared to the state-of-the art devices, the circulators/isolators made according to the present invention incorporate the confined-flux self-magnetized ferrite structure thus eliminating the use of conventional magnets.
    Type: Grant
    Filed: April 9, 2001
    Date of Patent: February 11, 2003
    Assignee: Renaissance Electronics Corporation
    Inventor: Karen Kocharyan
  • Patent number: 6515560
    Abstract: An active inductor includes an MOSFET having a gate, a drain serving as an output terminal and a grounded source, the MOSFET having a transconductance gm1, and a capacitor having opposite ends, one of which is grounded and the other of which is connected to the gate of the MOSFET and to a voltage-controlled constant current source having a transconductance gm, the capacitor having a capacitance C, the active inductor being operative with a small-signal output impedance Zo between the output terminal and the ground expressed as Zo=j&ohgr;{C/(gm1·gm)} (wherein &ohgr; is an angular frequency) and with an inductance Leq expressed as Leq={C/(gm1·gm)}.
    Type: Grant
    Filed: February 5, 2001
    Date of Patent: February 4, 2003
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Alberto O. Adan
  • Patent number: 6515556
    Abstract: It is to provide a high-frequency component using a small coupling line, capable of easily adjusting an electrical characteristic. A first transmission line including three line sections constructs a ¼-wavelength strip line. A second transmission line including three line sections also constructs a ¼-wavelength strip line. The line section on one-end side in the first transmission line is faced to the line section on one-end side in the second transmission line, while a dielectric sheet is disposed between both of the line sections, thereby mutually coupling both transmission lines electro-magnetically. The line section on another-end side in the first transmission line is also faced to the line section on another-end side in the second transmission line. While the dielectric sheet is disposed between both of the line sections, thereby mutually coupling both transmission lines electro-magnetically.
    Type: Grant
    Filed: November 8, 2000
    Date of Patent: February 4, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Noboru Kato, Noriaki Tsukada
  • Patent number: 6512427
    Abstract: A spurious signal reduction circuit which is connected to a main signal line. The spurious signal reduction circuit comprises a resistor having a terminal connected to the main signal line, an LC parallel resonance circuit and an LC series resonance circuit. The parallel resonance circuit has a resonance frequency which is equal to a main signal frequency and has a terminal connected to another terminal of the resistor. The series resonance circuit has a resonance frequency which is equal to a spurious signal frequency and has a terminal connected to the other terminal of the resistor.
    Type: Grant
    Filed: January 10, 2000
    Date of Patent: January 28, 2003
    Assignee: Fujitsu Limited
    Inventor: Yoshiaki Nakano
  • Patent number: 6512424
    Abstract: A magnetic member 2 for nonreciprocal circuit is fitted in a first hole formed in a dielectric substrate 1 and at least one magnetic member 3 is fitted in a second hole formed in a portion of the dielectric substrate 1, which surrounds the first hole. An electrical conductor is printed on surfaces of the dielectric substrate 1 and the magnetic member 2 for nonreciprocal circuit to form a micro strip line 4. A grounding conductor 5 is formed on the other surface of the dielectric substrate 1. Changing the magnetization of the magnetic member 3 for frequency regulation can reversibly perform a regulation of the frequency characteristics of the nonreciprocal circuit.
    Type: Grant
    Filed: April 13, 2001
    Date of Patent: January 28, 2003
    Assignee: NEC Corporation
    Inventors: Mitsuru Furuya, Osamu Myohga, Yoshitsugu Okada
  • Patent number: 6507249
    Abstract: The performance of broadband isolators and circulators can be characterized by the ratio fmax/fmin, where fmin and fmax are defined as the edges of the frequency band in which the devices have acceptable operating characteristics. For the most advanced isolators and circulators available today this ratio is approximately 3:1. This invention teaches how to improve broadband performance substantially. The present limitations are shown to be primarily due to two causes: 1.) lack of bias field homogeneity, and 2.) previously unrecognized low-field loss due to excitation of magnetostatic surface waves. These surface waves are excited at the dielectric/ferrite interfaces on the side faces of the ferrite platelets or discs in the devices. For stripline edge-mode isolators and stripline circulators, the undesired low-field loss can be reduced by using certain rf device structures in combination with suitable bias magnets.
    Type: Grant
    Filed: September 1, 1999
    Date of Patent: January 14, 2003
    Inventor: Ernst F. R. A. Schloemann
  • Patent number: 6504444
    Abstract: Holes are formed in a ceramic substrate before sintering, magnetic parts and dielectric parts are fitted in the holes and the substrate is sintered at a temperature equal to or lower than the sintering temperature of the magnetic parts. It is possible to obtain a very compact high frequency integrated circuit, particularly, a micro wave integrated circuit which can be utilized in a frequency band of several tens GHz, by using hard ferrite as a material of the magnetic parts and magnetizing them after the sintering.
    Type: Grant
    Filed: November 6, 1998
    Date of Patent: January 7, 2003
    Assignee: NEC Corporation
    Inventors: Mitsuru Furuya, Osamu Myohga, Yoshitsugu Okada
  • Patent number: 6504445
    Abstract: A structure for a low IMD passive microwave device, adapted for automated assembling and placement. The structure includes sheet metal housing having a bottom portion and a plurality of sides that are bent at 90-degree angle to the bottom portion. In each side there is a flare slot that can receive a tooth of a teeth cover. The structure has the aligning holes, slots and reference points on the entire stack to facilitate and automate the assembly process in manufacturing. The tuning stub resonators of a center conductor have the extended peripheral portions with the aligning half-moon holes. Those extended portions provide the condition when the operation range is maximally separated from the resonant frequency, thus providing the condition for the lower IMD. The housing is attached to a PCB. The input/output ports are formed on the PCB with the contact pads situated on both sides that are electrically connected using the PTHs.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: January 7, 2003
    Assignee: Renaissance Electronics Corporation
    Inventor: Karen Kocharyan
  • Patent number: 6504451
    Abstract: A multi-layered LC composite component achieves greatly increased attenuation in the proximity of a central frequency without increasing insertion loss. In the arrangement of the multi-layered LC composite component, an end of each of inductor patterns is connected to a connecting pattern to be short-circuited. These inductor patterns define inductors. Frequency-adjusting capacitor patterns are opposed to open-circuited ends of the inductor patterns to define capacitors. As a result, the capacitors and the inductors define LC resonators. The connecting pattern is opposed to shield patterns via insulating sheets to define a common capacitor.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: January 7, 2003
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Naoto Yamaguchi
  • Patent number: 6496083
    Abstract: The present invention aims to realize, in regard to a high frequency switch used for a mobile communication apparatus such as a portable telephone or the like, a dual band switch having simple structure and changeable to ON and OFF states in two bands. For realizing the aim, the present invention provide a dual band switch comprising a series circuit of a PIN diode (101) and its compensation circuit (102), and, the compensation circuit (102) is formed with a circuit having at least two series resonance points and one parallel resonance point. The above structure allows the impedance of the compensation circuit, which is capacitive in low frequency close to a direct current, to be inductive after undergoing the first series resonance point, whereby the parasitic capacity of the diode is canceled in the first band, and also to be inductive again after undergoing the parallel resonance point and the following series resonance point, whereby the parasitic capacity of the PIN diode is canceled in the second band.
    Type: Grant
    Filed: February 3, 1999
    Date of Patent: December 17, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Kushitani, Naoki Yuda, Hiroshi Takahashi, Makoto Fujikawa
  • Patent number: 6496080
    Abstract: A dielectric nonreciprocal circuit device, which has satisfactory nonreciprocal characteristics obtained by improving the structure of a part supporting magnetic members, is incorporated in a radio device. The dielectric nonreciprocal circuit device has an arrangement such that supporting members for supporting the magnetic members are not located where the magnetic members are abutted against dielectric strips or where the magnetic members are disposed in close proximity to the dielectric strips.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: December 17, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yutaka Ishiura, Hiromu Tokudera, Kei Matsutani
  • Patent number: 6496086
    Abstract: A saw device comprises input/output interdigital transducer (IDT) electrodes(11,12) provided on piezoelectric substrates (10), a first reflector electrode (13) following the input IDT electrode (11), and a second reflector electrode (14) preceding the output IDT electrode (12). The device satisfies the following inequality (1) to provide preferable characteristics in a pass band: 2(&thgr;−5)≦tan−1(D/L)≦2(&thgr;+5) where &thgr;: the inclination (in degree, except zero) of the first or second reflector electrode of the input and output IDT electrodes with respect to a plane perpendicular to the direction in which surface acoustic waves travel. D: the pitch (in micron) of the input and output IDT electrodes in the direction in which surface acoustic waves travel. L: the pitch (in micron) of the first and second reflector electrodes.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: December 17, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Shigeru Tsuzuki, Tsutomu Igaki, Ken Matsunami, Kazuki Nishimura
  • Patent number: 6492885
    Abstract: An LC component includes a coil conductor spirally wound around the outer peripheral surface of a wound core member having a substantially rectangular cross-section. A dielectric layer is arranged so as to cover the coil conductor. A capacitor electrode is provided on the dielectric layer so as to wind approximately once around the wound core member in the peripheral direction of the wound core member. The capacitor electrode includes first, second, third, and fourth surfaces. The capacitor electrode is divided by two cut grooves. One cut groove crosses the capacitor electrode obliquely from one side of the first surface of the capacitor electrode to the other side of the second surface adjacent to the first surface. Similarly, the other cut groove crosses the capacitor electrode obliquely from one side of the third surface of the capacitor electrode to the other side of the fourth surface adjacent to the third surface.
    Type: Grant
    Filed: July 1, 2000
    Date of Patent: December 10, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Satoshi Murata, Hideyuki Mihara, Etsuji Yamamoto, Minoru Tamada
  • Patent number: 6486746
    Abstract: A termination circuit for unused wires in an unshielded twisted pair (UTP) cable in a local area network (LAN) device. In an eight wire UTP cable, four wires may be unused. The four unused wires are shorted to each other at a point of termination which is electrically connected to ground across a terminating resistive element having a resistance value in a range of about 0.36 to about 0.62 of a differential impedance of the UTP cable, e.g., 36 to 62 ohms for a UTP cable having a differential impedance of 100 ohms.
    Type: Grant
    Filed: June 30, 2000
    Date of Patent: November 26, 2002
    Assignee: Intel Corporation
    Inventor: Stewart L. Gilbert
  • Patent number: 6483400
    Abstract: A passive low pass filter of a surface mounted device configuration has counter-wound coils and at least one capacitor. Each coil has a centerline. The centerlines are parallel to one-another and perpendicular to a plurality of plates of the capacitor. The windings of the coils and the plates of the capacitor are encased in a dielectric encapsulant.
    Type: Grant
    Filed: October 27, 2000
    Date of Patent: November 19, 2002
    Assignee: Delphi Technologies, Inc.
    Inventor: William Thomas Phillips, Jr.
  • Patent number: 6483394
    Abstract: An isolator is disclosed, in which a ferromagnetic sheet is placed into a shielding resin case together with garnet ferrite and an internal terminal sheet (with strip lines extending therefrom). Thus the leakage magnetic flux shielding effect is reinforced, and the bulk of the isolator is made compact. The constitution is as follows. That is, the internal terminal sheet (with the strip lines extending therefrom), a garnet ferrite, a plurality of insulating films and a ferromagnetic sheet are inserted into a shielding resin case in the cited order. Further, this structure is inserted into between upper and lower cases, and three dielectric devices and a chip resistor are disposed on a PCB and around the lower case, while a connecting terminal part with input/output terminals connected to the PCB electrodes is formed on the PCB.
    Type: Grant
    Filed: December 8, 2000
    Date of Patent: November 19, 2002
    Assignee: Samsung Electro-Mechanics Co., Ltd.
    Inventor: Chang Sik Kim
  • Patent number: 6476689
    Abstract: An LC filter includes a capacitor with a small residual inductance, and having a good attenuation property up to a high frequency range, so as to achieve a strong attenuation at particular frequencies and also being adapted for use with a large current. Two coils including a metal plate arranged in a spiral shape, are disposed in a serially connected state so as to generate a mutual inductance therebetween. Also, a capacitor electrode plate has a shape which is included in the shape of the coils when viewed from the axial direction thereof, in the vicinity of the connection point of the coils so as to be opposed to a portion of the coils, whereby the portion of the coils functions as a capacitor electrode.
    Type: Grant
    Filed: September 21, 2000
    Date of Patent: November 5, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Katsuyuki Uchida, Masami Sugitani
  • Patent number: 6476690
    Abstract: A laminated LC component has no directivity in terms of mounting and characteristics. A first set of coil conductors are electrically connected in series so as to define a first helical coil. A second set of coil conductors are also electrically connected in series so as to define a second helical coil. Capacitor electrodes are disposed such that they face each other with an insulating sheet disposed between the capacitor electrodes thereby forming a capacitor. The capacitor electrode at the ground side has a substantially cross shape and four ends of the substantially cross-shaped capacitor electrode are exposed at four respective sides of the insulating sheet. The insulating sheets are stacked on one another and fired so as to define a single unitary laminated block.
    Type: Grant
    Filed: April 19, 1999
    Date of Patent: November 5, 2002
    Assignee: Murata Manufacturing Co., Ltd.
    Inventors: Yasuhiro Nakata, Yoshihiro Fukuda, Takahiro Azuma, Hidetoshi Yamamoto
  • Patent number: 6472948
    Abstract: A step attenuator for use in attenuating an electromagnetic signal. The step attenuator includes a first path having a plurality of attenuator structures provided therein, each attenuator structure being selectively actuated to permit the signal to pass therethrough. A second path is disposed in parallel with the first path, the second path permitting the signal to selectively bypass the first path. A third path is disposed in series with the first and second paths and includes at least one attenuator structure that is selectively actuated to permit the signal to pass therethrough.
    Type: Grant
    Filed: July 10, 2000
    Date of Patent: October 29, 2002
    Assignee: Rockwell Collins, Inc.
    Inventors: Constantinos S. Kyriakos, James B. Ledebur, Leo G. Maloratsky, Carl E. Steen