Showing papers on "Stub (electronics) published in 1986"

High efficiency RF power amplifier

Abstract: A high efficiency RF power amplifier is disclosed in which a field effect transistor is operated in a class F mode. A third harmonic quarterwave open circuit transmission line stub having a Z O adjusted to provide capacitance series resonant with transistor inductance at the second harmonic is coupled to the transistor output lead to produce a low impedance at the channel drain of the transistor. Parallel resonance of the transistor die capacitance and interconnect inductance coupled to ground by the transmission line produces a third harmonic high impedance at the channel drain. Further lowpass output matching circuitry provides a constantly increasing impedance magnitude from the transistor die to the load and provides load mismatch isolation to the second and third harmonic impedances at the channel drain.

Excitation of Waveguide by Stripline- and Microstrip-Line-Fed Slots

Abstract: This paper presents investigations on coupling between stripline/microstrip line and a rectangular waveguide coupled through a slot in the ground plane which is fixed in the cross-sectional plane of the waveguide. A closed-form expression for the impedance loading on stripline/microstrip line is evaluated from knowledge of the complex power flowing down the rectangular waveguide supporting the dominant mode and discontinuity in the modal voltage in stripline/microstrip line. The reactance cancellation is obtained by terminating the stripline/microstrip tine exciting the slot in a short-circuited stub. The structure under this condition forms a transition between stripline/microstrip line and a waveguide. The design curves on slot length versus frequency are presented for different values of dielectric constants. The variation of coupling as a function of frequency and also the location of the slot is evaluated. Numerical results for slot coupling useful for the design of waveguide simulators are also presented.

Shunt-Connected Microstrip Radial Stubs (Short Paper)

Abstract: Radial-line stabs provide an interesting alternative to low-impedance conventional straight stubs.They are useful as filter elements in both series and shunt configurations. In this short paper, the planar circuit analysis previously performed for a series-connected radial stub is extended to the shunt configuration. Theoretical and experimental results are presented to verify the equivalent model for the shunt-connected radial stub.

Impedance matched, high-power, rf antenna for ion cyclotron resonance heating of a plasma

Abstract: A resonant double loop radio frequency (rf) antenna for radiating high-power rf energy into a magnetically confined plasma. An inductive element in the form of a large current strap, forming the radiating element, is connected between two variable capacitors to form a resonant circuit. A real input impedance results from tapping into the resonant circuit along the inductive element, generally near the midpoint thereof. The impedance can be matched to the source impedance by adjusting the separate capacitors for a given tap arrangement or by keeping the two capacitances fixed and adjustng the tap position. This results in a substantial reduction in the voltage and current in the transmission system to the antenna compared to unmatched antennas. Because the complete circuit loop consisting of the two capacitors and the inductive element is resonant, current flows in the same direction along the entire length of the radiating element and is approximately equal in each branch of the circuit. Unidirectional current flow permits excitation of low order poloidal modes which penetrate more deeply into the plasma.

Ceramic-metal braze joint

Abstract: A rotor-shaft assembly which includes a ceramic, solid hubbed turbine rotor (32) having an integral stub shaft (70) brazed within one end of a generally cylindrically shaped sleeve (72). A metal shaft (36) is either brazed or cold press fined within the other end of the sleeve in a torque trans- mining relationship. The stub shaft (70) is formed with an annular relief (71) around it in order to reduce the compressive forces acting on the stub shaft by the sleeve.

Ceramic transmitter combiner with variable electrical length tuning stub and coupling loop interface

Abstract: Transmitter combining apparatus includes up to five RF filters (100) coupled to a microstrip combiner (300) for combining up to five input signals for application to a common antenna. The RF filter (100) includes a ceramic resonator (116) sandwiched between first and second compensating discs (114 and 120) and first and second shield plates (142 and 148) for temperature compensation, low loss mounting and heat sinking of the ceramic resonator (116). Good thermal contact between the ceramic resonator (116), discs (114 and 120) and shield plates (142 and 148) is produced by a compressive force exerted by springs (144-147) of shield plate (142) when the top cover (112) is attached to the aluminum housing (124). The resonant frequency of the RF filter is tuned by means of an aluminum tuning shaft (102) and ceramic tuning core (118) which are positioned by brass bushing (133) in top cover (112). Input signals are coupled to each RF filter via respective input coupling loops (122) and output signals are coupled via corresponding output coupling loops (311) to the microstrip combiner (300). The microstrip combiner (300) includes a circuit board (310) having five transmission lines (601-605) and a short-circuited tuning transmission line (610), all coupled to a junction (620). The microstrip combiner (300) is tuned by means a variable impedance produced by varying the position of a dielectric tuning plate (630) with respect to a the tuning transmission line (610).

Vehicular multiband antenna feedline coupling device

Abstract: A multiband antenna mounting and feedline coupling arrangement includes a first transmission line segment secured in a mounting device for the antenna for coupling energy to and from the antenna. A second transmission line segment, extending, e.g., to grounded high band equipment, provides high band signal coupling with the first line and includes a direct current blocking capacitor in series in the ground return path of that second line segment, the capacitor having such a low impedance to high band energy that it presents negligible impedance to such energy. A third transmission line segment provides low band signal coupling with the first line by way of a part of the ground return path of the first line. A high band quarter wave, in the high band, filter stub transmission line is connected between the signal and ground return paths of the third transmission line adjacent to the point of coupling thereof to the first line. Several different implementations of the capacitor and transmission line segment combination are illustrated.

Shorted microstrip antenna with multiple ground planes

Abstract: A low and broadband shorted microstrip antenna is disclosed which is mainly applicable to a mobile body in a mobile communication system. A first grounding conductive sheet which faces a radiating conductive sheet is provided at both ends thereof with a second and a third grounding conductive sheets which are perpendicular to the first grounding conductive sheet, whereby a beam tilt characteristic of the antenna is improved. The passive element and a conductive stub are disposed atop the grounding conductive sheet. The passive element and the conductive stub face the radiating conductive element and serve to improve the impedance matching parameter of the microstrip antenna.

Hybrid power combiner and amplitude controller

Abstract: A dipositif (10) consists of a hybrid power combiner and a controller comprises a hybrid network with multiple branches, provided with PIN diodes (35, 40) used for selective ground contact intermediate points (26 , 31) branch lines (26, 30). When the PIN diodes are biased in conditions of open circuit, the apparatus (10) behaves like a conventional hybrid combiner, intended for example to combine the power from two input sources (16, 21) at the outlet orifice (22) of the device. When the PIN diodes are biased in conduction conditions, thus allowing the ground contact of the intermediate points (26, 31) branch lines, the apparatus (10) behaves as a multiple stub filter adapted and tuned to the desired band. Substantially all the power supplied by a single source of input power (21) will in this case supply the output (22) of the device.

Wideband balun realized by equal-power divider and short circuit stubs

Abstract: A balun comprises a one-to-two, equal-power, matched power divider having branch transmission lines whose lengths differ by 1/2 wavelength at a design frequency. The shorter of these two branch transmission lines has two 1/4 wavelength long, shorted stub transmission lines branching therefrom 1/4 wavelength apart.

Device for emptying containers

Abstract: A device for emptying flexible or rigid containers having flexible discharge stubs for in bulk goods where the discharge stubs are sealable by being tied shut and always issue into the emptying device from where the in bulk goods are conveyed out by partial vacuum or free fall. The emptying device (6) consists of an upright cylindrical housing (7) having an outside diameter less than the inside diameter of the discharge stub (4). This housing, when connected, is spanned by the discharge stub (4). At least two jaws (10) which when closed are spaced away from the housing wall are provided to which are mounted at least one elastic belt, a cord (11) or the like which in the closed state of the jaws (10) rests while prestressed over the entire periphery of the housing (7) against the discharge stub (4) spanning the housing (7).

Connection of two pipe sections which are arranged coaxially one behind the other, especially of an injection nozzle to the coaxially arranged connecting stub of an injection line

Abstract: A spring bracket (6) which is bent essentially into a U-shape is used to connect an injection nozzle (3) to a coaxially arranged connecting stub (1) of an injection line. This spring bracket (6) has a web (7) which runs transversely with respect to the longitudinal extent of the injection nozzle (3), and flaps (12) which are bent at right angles thereto and engage in a groove (13) in the injection nozzle (3). In order to attach the connecting stub (1), said stub (1) has a radial projection (10) which can latch into corresponding perforations (9) in the limbs (8) of the spring bracket (6). In order to be able to insert the injection nozzle (3) with the pushed-on spring bracket (6) into the connecting stub (1) as a structural unit, the limbs (8) of the spring bracket (6) are bent outwards. In consequence, guide surfaces are produced for the radial projection (10) of the connecting stub (1), so that the production of the connection is considerably simplified (Fig. 2).

Center stub still railway tank car construction

Abstract: A center stub sill railway tank car is disclosed having a generally cylindric, elongate tank. A center stub sill assembly is secured to the lower portion of the tank at each end thereof for transferring longitudinal train and lading loads between the tank and the center stub sill assembly. A bolster assembly is secured to the center stub sill and extends transversely of the car. An improved cradle assembly is secured to the lower end portion of the tank for reinforcing the tank bottom in the area of the center stub sill, the cradle assembly having an arcuate cradle extending at least in part circumferentially upwardly from the bottom centerline of the tank generally at the longitudinal position of the bolster assembly, and an upwardly facing hat section elongate cradle secured to the bottom end of the tank and extending inboard from the cradle. The center stub sill has vertical flanges extending inwardly from the bolster assembly on the outside of the hat section shaped cradle pad and welded thereto so as to transmit loading between the cradle pad and the center stub sill assembly.

Frame joint construction for bicycles and the like

Abstract: A frame joint for bicycles and the like includes a stub insert consisting of a base, a stub protruding from the base, and an annular shoulder at the junction between the base and the stub; a connecting member having a tubular end with an annular end face telescoping over the stub in a press fit; adhesive bonding the tubular end to the stub; and an annular collet positioned on the stub between the end face and the shoulder. The collet includes an inner end having a first lip portion which extends about and overlaps a periphery of the base adjacent to the shoulder and an outer end having a second lip portion which is beveled in a concave fashion to overlap and receive the end face of the connecting member. The first and second lip portions are joined by a continuous outer wall having a diameter greater than that of the tube end and the base, and an interior wall extending between the first and second lip portions having a diameter less than that of the tube end and base.

Matching circuit for a microwave device

Abstract: A microwave matching circuit, having a main line (for transmitting a high frequency signal) and a stub, formed close to the main line (for matching the input terminal of the high-frequency signal and the output terminal of the main line) includes a capacitor, for absorbing unnecessary components at the main line and other output terminals, connected between the main line and the stub.

Marine engine power take-off for a hydraulic pump

Abstract: A hydraulic pump is mounted on a bracket which, in turn, is mounted on a frame secured to a marine engine The mounting of the frame on the engine allows for substantially universal swiveling and translation adjustment to position a rearward-projecting stub shaft of the frame stationarily and in coaxial alignment with the forward-projecting front end portion of the engine crankshaft A cogwheel or pulley is rotatably mounted on the stub shaft and is joined to the engine crankshaft by a flexible coupling Such cogwheel or pulley drives a belt which powers the driven input wheel or pulley of the pump The substantial tension of the belt is applied to the stub shaft of the frame without transmission to the engine crankshaft, and the coupling of the pump to the engine is not effected by vibration, twisting or fore-and-aft surging of the engine in response to developed torque and thrust

Stub TLM modelling of heat flow in semiconductor devices

Abstract: Stub transmission lines can easily be introduced into existing TLM models for heat flow in semiconductor devices. They provide a convenient means of eliminating inter-nodal reflections that arise as a result of either geometric factors or the temperature dependence of the specific heat and thermal conductivity. Stub lines have been used to identify a minor error in a previously published TLM formulation.

Double-row anti-friction bearing, particulary for wheels of automotive vehicles

Abstract: In order to keep at least part of the axial and tilting forces that act on a bearing away from the stub shaft (99) supporting the bearing rollers (3) (5), the inner ring of the bearing is constructed of a removable section (4) that supports a first set of ball bearings (5). A second set of ball bearings (3) is supported directly on the stub shaft. The removable section (14) extends from the free end of the stub shaft (99) to a point located between a first plane containing the ball centers of the second set (3) and a second plane contacted by the outer surfaces of the balls in the second set. The second plane being between the ball centers of the first and second sets.

Band reflection type FET dielectric resonator oscillator

Abstract: A band reflection type oscillator includes a GaAs-FET having a source, a gate and a drain in which the drain is connected to ground. A stripline is connected to the gate, and a dielectric resonator is provided adjacent the stripline in a magnetically coupled relationship therewith. A stripline stub is electrically connected to the drain and positioned adjacent the resonator in a magnetically coupled relationship therewith, thereby defining a positive feedback circuit through the drain, said stripline stub, the resonator and the stripline to the gate. By the positive feedback circuit, the oscillation stability is improved.

Broadband lumped equivalent circuit for shunt-connected radial stub

Abstract: A lumped equivalent circuit for a radial stub is given that characterises the electrical behaviour of the component in terms of 'resonant frequency' and impedance level. The broad bandwidth validity of the proposed approach is also demonstrated.

TVRO receiver with surface mounted high frequency voltage-controlled oscillator

Abstract: A TVRO receiver utilizes an improved voltage-controlled oscillator (VCO) of the surface mounted type which has a wide bandwidth of operation extending into the microwave frequency range. The VCO comprises a dielectric substrate with a patterned-metal layer on one side and a surface mounted oscillator on the patterned-metal side of the substrate. The oscillator comprises amplifying means which produce an oscillating output by the use of regenerative feedback means including an open-circuit-stub inductance formed in the patterned metal layer, and a tunable resonant circuit coupled to the amplifying means in order to control the frequency of the oscillating output. The resonant circuit includes a short-circuit-stub capacitance formed within the patterned middle layer, at least one variable capacitance diode in series with the short-circuit stub, and means for applying a controllable tuning potential to the resonant circuit.

Method of manufacturing lateral header extensions

Abstract: An aluminum header tube having a plurality of integral and regularly spaced lateral extensions is formed according to a method which includes the steps of forming stubs for the extensions, inserting a tool through each stub and into the interior of the header tube, sizing each stub to reduce its inside and outside diameter and, while maintaining the clamp, withdrawing the tool through the stub to cause metal to flow outwardly, thus raising or lengthening the stub to the desired degree.

Large deflection pipe coupling

Abstract: This invention pertains to a pipe joint which allows greater joint deflection by the use of a bell stub between a pair of coupled pipes. The bell stub has a bell contour inside and a plain end contour outside.

Shorted microstrip antenna

Abstract: A low and broadband shorted microstrip antenna is disclosed which is mainly applicable to a mobile body in a mobile communication system. A first grounding conductive sheet (42) which faces a radiating conductive sheet (48) is provided at both ends thereof with a second (44) and a third (46) grounding conductive sheets which are perpendicular to the first grounding conductive sheet, whereby a beam tilt characteristic of the antenna is improved. A passive element (52) and a conductive stub (62) which is provided on the grounding conductive sheet, which faces the radiating conductive element, serve to improve an impedance matching characteristic.

Internal sewage line stub cutting tool having automatic bit adjustment

Abstract: A remote cutting tool for insertion into an underground sewage pipe for trimming branch line stub ends that extend into the sewage pipe. The cutting tool comprises a sled adapted to be drawn through the interior of the pipe by cables attached thereto. A cylindrical cutting bit is driven by a hydraulic motor, the motor and bit being retained on the sled through a hydraulic jack ram. The jack ram facilitates the axial movement of the motor and bit with respect to the sled as required to effect branch stub cutting. Expandable pneumatic sleeves are provided on the sled which, when inflated, lock the sled in fixed orientation in the pipe prior to each cutting operation. A guide member is positioned over the pneumatic sleeve adjacent the point of intended cutting to deflect the sleeve in the opposed direction and to align the cutting bit in close proximity to the sewer pipe wall at the point of stub pipe entry.

Stub for connecting a hose and especially for coolant hoses in internal combustion engines

Abstract: The invention relates to a stub support for connecting and supporting a hose connection wherein the stub has a rounded cross-section and is in configuration with peaks and valleys with steep tapering flanks facing the connection side of the stub and long tapering flanks facing the opposite direction.

Garment drying hanger

Abstract: Each hanger arm includes a stub shaft with a locking notch immediately adjacent. Elongated extender arms, one for each hanger arm, each include a hollow end which can be received onto a locking stub shaft and have detent parts to be snapped into the adjacent locking notch. To release an extender arm from the hanger body, it is swung outwardly and upwardly a slight amount, which removes the detent from the notch allowing the extender arm to be pulled off the hanger body stub shaft. The outer end of an extender arm may be provided with a similar stub shaft enabling a second extender arm to be releasably locked to a first extender arm providing further total arm length.

Loading/unloading device

Abstract: A reel loading/unloading device 1 for machinery 3, comprising a wheeled bogie 5 or trolley, a pair of upstanding, spaced-apart, support arms 9 carried by the bogie 5, each support arm 9 being provided with an upwardly open slot 10 of width capable of accepting a stub shaft 21 or axle projecting from each end of a reel 2, and lifting/lowering means 14-18 attached to the arms 9 and capable of lifting the stub shafts 21 from the bottoms 13 of the slots 11, and also capable of lowering the stub shafts 21 to the bottoms 13 of the slots 11.

Truss end structure for stub sill hopper cars

Abstract: In a stub sill type railway hopper car the shear plate is eliminated and a truss arrangement is located in the end structure resulting in less weight.

Prefabricated sleeve body for screened heavy-current cables

Abstract: In the case of a prefabricated sleeve body consisting of elastomeric material for connection of a screened heavy-current cable to an electrical apparatus, the cylindrical connecting stub (1), which can be connected to an insulating plug, is provided on its outer surface in the circumferential direction with projections (5) which extend in the axial direction of the connecting stub. When the insulating plug is twisted out, the connecting stub can be fixed on the projections in the circumferential direction, for example by means of a positive lock of the surrounding metal housing (10) or by means of a special holding tool.