Abstract: A tuned resonator circuit topology is disclosed that permits implementation of narrow band-pass filters having high loaded Q and optimal coupling (for low insertion loss) using a parallel tuned resonator topology at frequencies in the 1 to 2 GHz range and beyond. The topology consists of a mirror image of the parallel tuned circuit about the signal line of a conventional parallel tuned circuit to effect a cancellation of virtually all of the induced currents between the inductive elements of the resonators. This reduction in induced currents reduces the magnetic coupling between the resonators, thereby offsetting the increase in overall coupling between the resonators as frequency increases, and thereby serves to maintain optimal coupling between the resonators as the frequency of operation increases. Moreover, the mirror image topology increases the parallelism between the inductive elements in the resonators, thereby decreasing the inductance values and permitting an increase in capacitance values.
Abstract: A compact dual element cascade circulator in which performance is enhanced while the size of the overall device is reduced. The circulator includes a plurality of junctions connected in cascade to provide a plurality of non-reciprocal transmission path between signal ports on a network, and a metal housing with a cover in which the junctions are disposed. The plurality of junctions includes a single oblong permanent magnet, a dual ferrite component including two (2) oblong ferrite elements, a dielectric constant medium disposed between the ferrite elements, and a plurality of conductor portions sandwiched between the ferrite elements. A single impedance matching structure is coupled between successive junctions.
Abstract: The present invention is intended to provide a line filter having an outstanding attenuation characteristic over a wide frequency band from low frequency band to high frequency band, with an improved elimination characteristic for common mode noises. To achieve this object, the invention incorporates a structure wherein a first coil unit (14) for second band and a second coil unit (16) for second band are disposed vertically to a closed-loop magnetic core (11).
December 26, 2001
Date of Patent:
September 23, 2003
Matsuhita Electric Industrial Co., Ltd.
Hiroshi Tomita, Toshinori Oda, Hirotaka Ishikawa, Tatsuya Mori
Abstract: A microstrip to circular waveguide transition having an elongated circular waveguide portion and a stripline circuit portion disposed within the waveguide portion. The stripline includes a strip conductor disposed in a strip conductor plane. The strip conductor extends along a longitudinal axis of the circular waveguide portion from a first region of the transition to a longitudinally spaced second region of the transition. The stripline circuit portion includes a pair of overlying ground planes extending along the longitudinal axis from the first region to the second region, such pair of ground planes being disposed in overlying planes parallel to the strip conductor plane.
Abstract: A Printed Circuit Board (PCB) (30, 70, 102) and method of manufacturing same. The PCB (30, 70, 102) includes an embedded shielded conductor structure comprising a dielectric layer (42) disposed over a first conductor (40, 80, 84), and a second conductor (38, 78, 82) proximate and coupled to said first conductor (40, 80, 84) being disposed over said dielectric layer (42). The first (40, 80, 84) and second (38, 78, 82) conductors are juxtaposed to form a broadside coupled stripline. A first low noise ground layer (54, 94) is disposed under said first conductor (40, 80, 84), and a second low noise ground layer (52, 92) is disposed over said second conductor (38, 78, 82), these low noise ground layers typically being coupled to chassis ground. RF (32, 72) and digital (34, 74) portions of the PCB (30, 70, 102) are separated and isolated by a vertical ground shield (36, 76). The use of heavy, bulky RF connectors and cables may be eliminated or reduced.
Abstract: An isolator serving as a nonreciprocal circuit device includes a permanent magnet, a ferrite to which a DC magnetic field is applied by the permanent magnet, a plurality of center electrodes placed on the ferrite, and upper and lower casings for accommodating the permanent magnet, the ferrite, and the center electrodes. The upper and lower casings are made of a material chiefly containing iron, and the average value of the surface roughness of the casings is less than or equal to 0.9 &mgr;m. The front and rear surfaces of the upper and lower casings are Ag-plated.
Abstract: The invention discloses a nonreciprocal circuit device, a composite electronic component, and a communication apparatus, which can achieve miniaturization and cost reduction while having good characteristics. In the nonreciprocal circuit device, one of a plurality of matching capacitors is connected in series between one of a plurality of central conductors and a port of the central conductor. An end of each of the remaining matching capacitors is connected in parallel to each of the remaining central conductors, and the connecting parts are continued to ports of the remaining central conductors.
Abstract: A nonreciprocal circuit device includes a metal lower case made of magnetic metal, a resin terminal case, a central electrode assembly, a metal upper case made of magnetic metal, a permanent magnet, and an electric-circuit-component assembly. The electric-circuit-component assembly is disposed on a side of the permanent magnet, and is formed such that a coil and a capacitor are mounted on a substrate. The electric-circuit-component assembly is disposed in parallel to the thickness direction of the permanent magnet so as to be below the surface of the permanent magnet, and has a portion overlapping with the permanent magnet.
Abstract: A transmission system is provided for a power source to transfer power to equipment housed within a Faraday cage. The transmission system transfers energy along a non-conductive path yet remains in conductive contact with the Faraday cage. This prevents EMI disturbing electrical power provided within the Faraday cage and damaging equipment housed within the cage. The transmission system enables mains power to be transmitted to equipment housed within the Faraday cage without the need to provide conventional electric filters. The performance of the Faraday cage in shielding electromagnetic radiation is not compromised. Nor is the ability of the Faraday cage to shield electromagnetic radiation generated by communications equipment within the cage compromised.
Abstract: A nonreciprocal circuit device is provided which has an improved reflection characteristic of the port of the center conductor which is disposed orthogonally to the side-walls of a yoke. In this nonreciprocal circuit device, the conductor width of one center conductor which is disposed orthogonally to the side-walls of the yoke is made wider than that of each of the two other center conductors.
Abstract: A thin-film bandpass filter is provided. The thin-film bandpass filter includes a substrate, a plurality of first capacitors formed on the substrate, each being electrically connected in series, at least one second capacitor electrically connected to branch terminals positioned between the plurality of first capacitors, an inductor electrically connected in parallel to the second capacitor, and a plurality of supports for propping up the inductor so that the inductor is separated a predetermined space above the substrate and/or the second capacitor. The first and second capacitors, respectively, include a first metal layer, a dielectric layer, and a second metal layer, all of which are sequentially formed on the substrate. The inductor is comprised of a predetermined pattern of a thin-film metal layer propped by the plurality of supports, to both ends of which are electrically connected to the first and second metal layers of the second capacitor, and suspended by the substrate and/or the second capacitor.
Abstract: A directional coupler comprises a coupler circuit board which is mounted substantially perpendicular to the surface of a parent circuit board. First and second upper traces are disposed on the opposing surfaces of the coupler circuit board. The coupling between the upper electrically conductive traces determines the odd mode impedance of the coupler. First and second lower traces are also disposed on opposing surfaces and connected to ground. The upper and lower traces are arranged such that the even mode of the impedance is determined by the coupling between the first upper trace and the second lower trace and the coupling between the second upper trace and the first lower trace.
August 17, 2001
Date of Patent:
July 8, 2003
Dmitriy Borodulin, Timothy Dittmer, George Cabrera
Abstract: An RF power combiner. A plurality of RF inputs connect to a power combiner switch assembly. RF switches connect each input to a common node. A single stub matching circuit connects between the common node and an output node such that an open-ended transmission line stub extends from the output node. An RF output connector feeds an RF output connection from the output node. The stub of the L-match circuit has fixed length or variable length configurations. As a consequence, the impedances at the common and output nodes are more closely matched.
Abstract: A multilayer LC composite component minimizes the inductances of ground patterns to prevent electromagnetic waves from leaking outside the component. The multilayer LC composite component includes ground patterns having large areas arranged in the upper and lower sections of the component, with inductor patterns and resonant capacitor patterns arranged between the ground patterns. The ground patterns have portions extended in different positions such that no clearance is left between the extended portions in plan view.
Abstract: A nonreciprocal circuit device which can be miniaturized, and can achieve low insertion loss, having plate-like capacitors disposed vertically. Single plate capacitors are arranged vertically so that their electrode faces are at an angle of 90 degrees to a ferrite, and in addition, their bottom faces are at a position above the bottom half of the thickness of the ferrite, or more preferably, at a position higher than the top face of the ferrite.
Abstract: Conductive EMI in motor drive circuits is reduced by interposing inductors in the ground line. The common mode current enters the motor drive circuit through the two supply leads and leaves the system through the ground lead. The ground current typically is very high frequency but very low in rms amperage. Interposing an induction (low current, very high L) in the ground line advantageously reduces EMI. The inventive method reduces.or eliminates the need for filtering capacitors across the rectifier of the motor drive circuit. In addition, the inventive method minimizes the common mode choke to merely a wraparound ferrite core over the input wires. EMI emissions are reduced further by sandwiching ground traces along with power traces and connecting to.the heat sink with the shortest possible route. This reduces the ground loop area, which consequently reduces emissions.
Abstract: A compact nonreciprocal circuit device in which a large amount of attenuation can be obtained at a predetermined frequency band without increasing cost. In this nonreciprocal circuit device, three central conductors are arranged in such a manner that the conductors mutually intersect on a ferrite member to which a DC magnetic field is applied. A matching capacitor connected to the port of a first central conductor is designed to have a low self-resonance frequency so as to be equal to or lower than four times the central frequency of a pass band. With this arrangement, since the matching capacitor acts as a trap filter, major spurious components such as the second harmonic and third harmonics can be efficiently attenuated without increasing the number of components to be used.
Abstract: A cable television multi-tap system for forwarding signals to multiple customers from a main cable, and for receiving individual return signals from respective subscribers includes a printed circuit board secured to the inside face of the respective tap plates of a plurality of multi-taps, respectively, with each printed circuit board including at least first and second electrical receptacles for receiving a selected one of a plurality of first and second plug-in modules, respectively, said plurality of first plug-in modules providing different levels of directional coupling, respectively, and said plurality of second plug-in modules providing individually one or a combination of different levels of forward equalization, return path or backward equalization, cable simulation, high tap value filtering, high pass filtering, low pass filtering, band rejection, shunting, and noise filtering to optimize the signal quality of signals forwarded from the headend of the system to subscribers, and return signals from s
Abstract: A feedthrough capacitor filter assembly includes a capacitor having first and second sets of conductive electrode plates embedded within an insulative or dielectric body, and a leak detection vent for facilitated hermetic seal testing prior to use. At least one feedthrough terminal pin extends through the capacitor in conductive relative with the first set of electrode plates, and an outer ferrule is mounted about the capacitor in conductive relation with the second set of electrode plates. A hermetic seal is seated within the ferrule at one side of the capacitor to prevent leakage of fluid through the filter assembly. The hermetic seal is spaced from a face of the capacitor to form a gap therebetween.
Abstract: An alignment frame for a passive radio frequency ferrite isolator or circulator aligns ferrite discs with the circuit and the housing in which these components are encased. The fragile leads of the circuit are supported by the alignment frame, thereby creating a more durable and robust package design for handling and customer product interfacing. No adhesive is used, thereby reducing manufacturing time and increasing reliability of the device.
June 14, 2001
Date of Patent:
May 20, 2003
Tyco Electronics Corporation
Stanley V. Paquette, Thomas T. Lee, Randal W. Chalifour