Showing papers on "Stub (electronics) published in 1994"

Space mapping technique for electromagnetic optimization

Abstract: We offer space mapping (SM), a fundamental new theory to circuit optimization utilizing a parameter space transformation. This technique is demonstrated by the optimization of a microstrip structure for which a convenient analytical/empirical model is assumed to be unavailable. For illustration, we focus upon a three-section microstrip impedance transformer and a double folded stub microstrip filter and explore various design characteristics utilizing an electromagnetic (EM) field simulator. We propose two distinct EM models: coarse for fast computations, and the corresponding fine for a few more accurate and well-targeted simulations. The coarse model, useful when circuit-theoretic models are not readily available, permits rapid exploration of different starting points, solution robustness, local minima, parameter sensitivities, yield-driven design and other design characteristics within a practical time frame. The computationally intensive fine model is used to verify the space-mapped designs obtained exploiting the coarse model, as well as in the SM process itself. >

Quantum waveguide transport in serial stub and loop structures.

Abstract: We have studied the quantum transmission properties of serial stub and loop structures. Throughout we have considered free-electron networks and the scattering arises solely due to the geometric nature of the problem. The band formation in these geometric structures is analyzed and compared with the conventional periodic-potential scatterers. Some essential differences are pointed out. We show that a single defect in an otherwise periodic structure modifies band properties nontrivially. By a proper choice of a single defect one can produce positive-energy bound states in continuum, in the sense of von Neumann and Wigner. We also discuss some magnetic properties of loop structures in the presence of Aharonov-Bohm flux.

Microstrip filter design using direct EM field simulation

Abstract: For the first time, we present minimax filter design with electromagnetic (EM) simulations driven directly by a gradient-based optimizer. Challenges of efficiency, discretization of geometrical dimensions, and continuity of optimization variables are overcome by a three-stage attack: 1) efficient on-line response interpolation with respect to geometrical dimensions of microstrip structures simulated with fixed grid sizes; 2) smooth and accurate gradient evaluation for use in conjunction with the proposed interpolation; and 3) storing the results of expensive EM simulations in a dynamically updated database. Simulation of a lowpass microstrip filter illustrates the conventional use of EM simulation for design validation. Design optimization of a double folded stub bandstop filter and of a millimeter-wave 26-40 GHz interdigital capacitor bandpass microstrip filter illustrates the new technique. >

Combination frame-supported box receiver and self-stabilizing bed extension

Abstract: The present invention makes beneficial use of a vehicle's single point box receiver hitch by transferring an underlying frame mount of the box receiver both outward and adjustably upward simultaneously for load transfer at to a load-supporting cross beam in order to provide a two-axis, cantilevered extension for a pickup truck. The extension apparatus when viewed from above is T-shaped and includes two pieces constructed from box iron. One piece is a longitudinal-running box beam welded at an upward cantilever angle to a short stub section. The second piece is T-shaped when viewed from above and it includes a single adjustment telescoping transition beam which serves as the transition from the longitudinal box beam to the load-supporting cross beam that is transversely oriented relative to the longitudinal beam. A second stub is rigidly connected to the cross beam and it is adjustable by being telescoped over the first angled stub.

Coupling between different leaky-mode types in stub-loaded leaky waveguides

Abstract: Several leaky-wave antennas have been described in recent years that possess excellent properties, and they all have in common a parallel-plate stub guide of finite height as part of the cross section. For taller stubs and for larger leakage rates (wider radiated beams), some interesting new exotic interactions occur due to coupling between the desired leaky mode and another leaky mode, which is a modification of the "channel-guide" mode. Although we have described such coupling behavior briefly previously, this basic new feature (the coupling between two leaky (complex) modes) is not generally known, and is discussed here in more detail and in a more general context. In addition to a broad qualitative discussion, numerical results are presented for structures based on NRD guide and on stub-loaded rectangular guide. We believe that these effects are universal to all leaky-wave structures that possess a finite stub height in the cross section, so that the discussion here serves as a model for what to expect for other structures. >

Automatic gear changing system

Abstract: An automatic electromechanical gear changing system for automatically derailing the endless chain of a multi-speed bicycle from one rear transmission sprocket to another rear transmission sprocket to effect rear transmission gear shifting. The automatic gear changing system includes a main housing member mounted to a down tube of the bicycle, a handlebar-mounted console which displays various system parameters for the rider (type of program in use by system, speed, gear, battery level, trip miles), and a microprocessor unit disposed within the console for initiating, controlling, and terminating transmission gear shifting of the endless chain on the rear transmission sprockets. The main housing member encloses a drive motor, a linear actuator threaded shaft which is actuated for rotational motion by the drive motor, a linear actuator stub mounted upon the shaft and selectively engaged by the shaft for linear reciprocal movement within the housing member, and a cable attachment for attaching an end of the rear derailleur cable to the stub so that selective linear movement of the stub shifts the derailleur cable and causes the derailment of the chain from one sprocket to another sprocket. Embedded in each housing member is an inductance coil which encompasses a portion of both the stub and the shaft, and the linear movement of the stub within the housing induces voltage changes in the coil which correspond to specific gears of the bicycle. Such voltage changes are interpreted by the mpu to initiate, control and terminate automatic gear shifting.

Helical resonator filter including short circuit stub tuning

Abstract: The present invention relates to a radio frequency filter the resonators (6,7) of which are made up of a wire wound into a cylindrical coil comprising a number of turns and of a surrounding casing (41). Finger-like projections (3) of an insulating plate (1) support the conical coils from the inside, and the coupling to the resonator is from a microstrip line (8), at a tap point (21), on the insulating plate. Each cylindrical coil has, adjoining the first turn, a straight portion (2) which is parallel to the axis of the cylindrical coil and extends towards the bottom plate (44) of the filter. On the inside surface of the bottom plate (44) there is a lead (51) one end (E) of which is short-circuited and the other end open, and the tip (12) of the straight portion (2) adjoining the cylindrical coil (6) is in contact with this lead (51). In this case, in spite of any rotation of the cylindrical coil relative to its own axis at the assembling stage of the filter, the distance of the tap point from the short-circuited end (E) of the lead (51) will remain unchanged, in which case the tap impedance will not change. The lead (51) is preferably a microstrip line on the surface of the insulating plate.

Activatably energy-absorbing component

Abstract: The energy-absorbing component comprises a deformable hollow structure which may be enclosed by a housing, the hollow structure being connected to a pressure-fluid source via a connection stub.

Capacitively coupled high frequency, broad-band antenna

Abstract: A capacitively coupled high frequency broad-band antenna comprising a stub having a tubularly shaped lower end that is capacitively coupled to a first terminal element for the center conductor of a transmission line. The outer conductor of the transmission line is connected to a base support element which is accurately spaced from the first terminal element by a dielectric spacer element; and the three elements are encapsulated and hermetically sealed by a plastic molded housing.

Space mapping technique for electromagnetic optimization

Abstract: We offer space mapping (SM), a fundamental new theory to circuit optimization utilizing a parameter space transformation. This technique is demonstrated by the optimization of a microstrip structure for which a convenient analytical/empirical model is assumed to be unavailable. For illustration, we focus upon a three-section microstrip impedance transformer and a double folded stub microstrip filter and explore various design characteristics utilizing an electromagnetic (EM) field simulator. We propose two distinct EM models: coarse for fast computations, and the corresponding fine for a few more accurate and well-targeted simulations. The coarse model, useful when circuit-theoretic models are not readily available, permits rapid exploration of different starting points, solution robustness, local minima, parameter sensitivities, yield-driven design and other design characteristics within a practical time frame. The computationally intensive fine model is used to verify the space-mapped designs obtained exploiting the coarse model, as well as in the SM process itself

Cable seal for house of switch-cabinet wall entrance

Abstract: A seal and strain relief device for use when cables pass through walls has a clip (3) for the wall with an outside thread (5) on a stub through which the cable passes. Inside the stub are ribs so that when the nut (6) is run down the stub, the cable is held tight. The nut and the clip are both split so that the cable can be laid inside them, there being a tongue-and-groove arrangement for snapping the two halves together. The clip in its joined- together state is like a grommet but the two halves are hinged so that it can open out almost flat.

End-on transmission line-to-waveguide transition

Abstract: A transmission line-to-waveguide transition that includes a microstrip impedance transformer for matching the impedance of an input transmission line to that of a flared slotline is disclosed. The slotline's width is sufficiently small such that when the transition is inserted into a waveguide the slotline is spaced inward from the waveguide's inner walls. A balun bi-directionally couples the unbalanced signal on the microstrip to a balanced signal on the slotline. The signal propagates along the slotline and is capacitively coupled to the waveguide. A trimmable tuning stub is used to adjust the resonant frequency of a parasitic cavity formed between the transition and the waveguide to increase the transition's effective bandwidth. A tapered dielectric insert is positioned inside the waveguide to decrease its size and to improve the coupling efficiency of the transition.

Pumping process for operating a multi-phase screw pump and pump

Abstract: The invention relates to a pumping process for operating a multi-phase screw pump with at least one feed screw surrounded by a housing having at least one intake stub on one side and at least one discharge stub at its top, in which the intake medium is conveyed parallel to the screw shaft in a continuous low-pulsed stream and continuously discharged at the discharge stub. The invention also relates to a multi-phase screw pump. In order to prevent the drawbacks usually occurring in dry running phases, the invention proposes that a partial liquid volume flow (liquid circulation) be separated on the pressure side and returned in metered quantities into the intake region and thus kept in circulation.

Semiconductor device with lead frame of molded container

Abstract: The molded type semiconductor device has a semiconductor chip mounted and molded on a lead frame. The device includes a stub which has an open end at a portion of the lead frame and which is connected to a ground electrode of the semiconductor chip, and a mold resin which molds the stub together with the semiconductor chip. The stub has a length that is a 1/4 wavelength of a signal wavelength used in the device. The stub is formed in a zigzag form or a spiral form. Due to such stub, the satisfactory grounding is ensured to accomplish a simple molded type structure and to improve circuit characteristics.

Stub axle assembly for conveyor roller

Abstract: A conveyor roller assembly comprises a roller supported at opposite ends on first and second opposing end supports with first and second axle members. Each of the axle members comprises a stub axle having one end securely fixed to a mounting flange. Each mounting flange is attached to a respective one of the end supports with the stub axles protruding into an adjacent end of the roller for supporting the roller between the end supports. A bearing member is inserted in each end of the roller for engaging the axle members. Preferably, the mounting flange comprises a molded plastic element having a generally flat, elongated configuration with a pair of spaced apertures for passing of mounting screws therethrough.

Non-resonant antenna and feed apparatus therefor

Abstract: A monopole radiating blade antenna comprising a driving, high impedance stub mounted to the face of the blade that functions as part of the radiator as well as part of a shunt path between the blade and the base plate. The shunt path is completed by an air coil inductor connected between the center conductor of the stub and the base plate. One embodiment provides the input connector wire and stub in vertical alignment along the center vertical axis of the blade. Another embodiment arranges the stub to be off-set from the input wire. Some advantages over conventional blade antennas include increased gain at low angles of elevation above the horizon, good impedance match over a wide range of frequencies without using conventional 1/4 wave length stub matching that can introduce dielectric losses, low resistance to ground to bleed off static electricity and lightning, non-loading of the high impedance path at design frequencies, and good accommodation of 5/8 wavelength radiator blade dimensioning.

Mechanical locking arrangement for sliding door driven by drive motor

Abstract: The two door panels in the closed state are automatically locked by a device which is located on running carriages which move towards each other with their ends. The device works mechanically and comprises a locking hook (2) rotatably located on a running carriage end and which hooks behind a locking bolt (4) located on a running carriage end. The locking is released by a driver piece (5) on which a driver is fixed, which works in conjunction with a release curve. The driver piece is connected to the drive belt (8) on the upper and lower stub end by a fixture (30). In the driver piece an angular recess (15) is provided in which a driver pin (13) engages.

Guidewire extension wire and connector assembly

Abstract: The guidewire extension wire and connector assembly comprises: a guidewire extension wire having a distal end portion including, extending toward a distal end of the guidewire extension wire, a break-away neck, a reduced-in-diameter stub section and a larger-in-diameter distal stub end; an inner sleeve having an inner end fixed to the guidewire extension wire proximally of the break-away neck and an outer end extending to the larger-in-diameter distal stub end; an outer sleeve having an inner end thereof fixed to the larger-in-diameter distal stub end; and, a fixing mechanism within an outer end of the outer sleeve adapted to engage a generally cylindrical reduced-in-diameter proximal stub end of an initially inserted guidewire.

Die registration and mounting system

Abstract: A novel system for mounting a die on a base is provided. Such a die/die mounting system combination includes a die, the die having a fixed countersunk aperture adjacent one lateral edge thereof, and having a countersunk aperture longitudinally-locatable within a longitudinally-extending slot adjacent an opposite lateral edge thereof. It also includes a pair of indexing nuts, each indexing nut including (i) a nut element provided with a geometrically-shaped head and a depending stub, at least the stub being pierced by an internally-threaded hole, and (ii) an indexing element having an upper externally-threaded shaft, a geometrically-shaped waist and a depending indexing portion, the depending indexing portion including an upper cylindrical end and a lower frusto-conical end. One such indexing nut is secured within the die with the stub of the nut element within the countersunk fixed aperture and with the indexing element firmly threaded into the internally-threaded hole. The other the indexing nut is secured within an accurately-predetermined countersunk aperture which is longitudinally-located along the longitudinally-extending slot, with the stub of the nut element within the longitudinally-located countersunk aperture and with the indexing element firmly threaded into the internally-threaded hole.

Radio-frequency integrated circuit device having adjustable matching circuit

Abstract: A radio-frequency integrated circuit has a transmission line which is short-circuited at an RF short-circuiting point to ground through an RF short-circuiting and DC blocking capacitor. The transmission line is connected to a bias supply point. The circuit has a matching circuit constituted by the transmission line and has a short-circuit stub and an adjusting capacitor. The short-circuit stub has first bonding points to which the bias voltage is applied and the adjusting capacitor has second bonding points which are selectively wire-bonded with the first bonding points. By selecting the positions at which the bonding points are interconnected, the impedance of the matching circuit can be adjusted.

Broadband high efficiency full wave open coaxial stub loop antenna

Abstract: A broadband, high-efficiency loop radiator is characterized by a coaxial loop one wavelength in circumference with a continuous center conductor fed through a coaxial T feed and a discontinuity of the outer shield next to the feed point of 50 ohms input impedance. Radiation occurs as a result of this transmission line discontinuity resulting in a reflected wave back down the shield. The one wavelength dimension of the loop generates two in phase electric dipoles spaced one diameter apart resulting in a bidirectional radiation pattern of 3 dBil and a 30% operational bandwidth due to the frequency compensation of the open stub. The open stub loop antenna acts as a low loss parallel tuned circuit appearing across a generator and the series impedance of the loop antenna resulting in increased bandwidth.

A compact, high power notch filter with adjustable F/sub 0/ and bandwidth

Abstract: The network described is a notch filter, synthesized as a capacitively-coupled short circuited shunt stub design. A well-known equivalence between open circuited, quarter wavelength high-impedance stubs, and capacitively coupled short-circuited stubs of lower impedance, is used iteratively to achieve a design with some innovative features: The shunt stubs are all the same impedance; typically; 50 /spl Omega/. The series 90 degree coupling lines are also the same impedance (again typically 50 /spl Omega/). Dimensions and components may thus be easily selected for high-power and low-loss operation. The coupling capacitors (which are in series with the stubs) are adjustable without compromising Q. Re-entrant stubs are used which allow a mixed lumped-distributed stub response and easy adjustment of stub lengths. A rugged coaxial construction is adopted with nothing cantilevered or unsupported. These features result in a design which is quite compact, tunable over a wide range of center frequencies, allows for adjustable bandwidth and thus selectivity, while intrinsically exhibiting high-power capability, low passband loss, and suitability for operation in demanding environments. >

The OSPF NSSA Option

Abstract: This document describes a new optional type of OSPF area, somewhat humorously referred to as a "not-so-stubby" area (or NSSA). NSSAs are similar to the existing OSPF stub area configuration option but have the additional capability of importing AS external routes in a limited fashion.

Tunable circuit board antenna

Abstract: An antenna is provided on a circuit board which has an elongated stub, having an end connected through the dielectric circuit board to a ground plane. The combination of the ground plane, stub and dielectric forms a resonant cavity. The resonant frequency of the cavity is adjustable by selectably sorting through holes provided in the end of the stub opposite to where the reference ground plane is connected to the stub.

Micro wave frequency device

Abstract: PURPOSE: To provide the device that is provided between a waveguide and a transmission line, contains and protects an integrated circuit, has performance required as a housing, is proper to connect the transmission line and a microwave frequency stub contained in the housing simply manufacture with reliability and is able to enclose the line and the integrated circuit CONSTITUTION: At least one transition part is provided between a transmission line 24 that is integrated on a board 23 made of a hard material and placed in a 1st microwave frequency cavity 31 and a waveguide 100 made of 2nd microwave frequency cavities 102a, 102b, and open ends 25a, 25b of the transmission line are placed to the transition part, a probe with a length inserted in the waveguide cavities at a point apart from a short-circuit closing a waveguide open end by a distance D is formed by the open ends, the transition part is provided with an impedance matching system and the board 23 is made of a material with a high dielectric constant

Parellel strip line cable

Abstract: PURPOSE:To provide a high frequency transmission path which can achieve a high performance without making the whole high frequency apparatus large sized. CONSTITUTION:An insulating body 2 is provided between a pair of parallel earth conductors 4, 4, and a center conductor 5 is installed inside of the insulating body 2 having plasticity or flexibility. Inside of this insulative body 2 a circuit element part is furnished which has a stub, inductance function part, resistance function part. capacitance function part, etc.

Engine exhaust turbocharger

Abstract: The turbo charger has a compressor rotor (1) which is fixed to the stub end (3) of the turbine shaft (4). At the centre (5) of the rotor rear wall (6) is a round extension (7) of the latter, containing a central blind hole (8) extending no further than the wall. The blind hole is tapped (9) and engaged by a screw thread (10) on the shaft stub end. There can be a guide (11, 12) on the latter before and after the threaded portion, each fitting in a mating seat (13, 14) in the blind hole.

Tuned stripline antenna with a sail

Abstract: An antenna is provided on a circuit board (10) which has an elongated stub (14), having an end connected through a dielectric to a ground plane (12). The ground plane/stub combination forms a resonant cavity (18). The stub (14) has a electrically conductive sail (20) for increasing the omnidirectionality and sensitivity of the antenna.

Controllable-temperature roll

Abstract: A thermally regulatable calendar roll, e.g. for drying paper webs, can have a roll body centered on a pair of flanged stub shafts wherein at least one flange shaft at one end of the roll body may be provided with at least one annular groove or chamber communicating with heating bores of the roll body. The pitch circle of the heating bores is located outwardly of the pitch circle adapting outwardly of the flanges to the roll body and the heating medium is fed through at least one of the stub shafts to the annular groove and the bores.

Rock bit and improved forging method for manufacturing thereof

Abstract: A method of manufacturing a roller cone type drill bit, or main body thereof, includes forging a monolithic main body forging comprising a shank blank extending longitudinally at one end and a plurality of circumferentially spaced leg stubs at the other end; turning the shank blank to form a threaded section; rotatably mounting a respective roller cone on each of a plurality of journal members, each journal member being carried at one end of a respective leg extension; and welding a respective one of the leg extensions to each of the leg stubs. The main body is forged with its longitudinal centerline perpendicular to its flash line, the latter being located well inward of the leg end of the forging. The radially outer surface of each leg stub is forged to taper radially inwardly from the flash line to the outer end of the leg stub, and subsequently machined to remove the taper, resulting in a radially outer surface of each leg stub circumferentially wider in the vicinity of the former flash line than at its outer end.