Showing papers on "Stub (electronics) published in 1995"

High performance microshield line components

Abstract: Several millimeter-wave passive components have been fabricated using the microshield transmission line geometry, and their performance is presented herein. Microshield is a quasi-planar, half-shielded design which uses a thin dielectric membrane (1.5 /spl mu/m) to support the conducting lines. This approach provides a nearly homogeneous, air-filled environment and thus allows extremely broad-band TEM operation. This paper examines the conductor loss and effective dielectric constant of microshield lines and presents results on transitions to conventional coplanar waveguide, right-angle bends, different stub configurations, and lowpass and bandpass filters. Experimental data is provided along with numerical results derived from an integral equation method. The microshield line is shown to be very suitable for high performance millimeter and submillimeter-wave applications. >

Steel moment resisting frame beam-to-column connections

Abstract: Steel moment resisting frame (SMRF) connections between vertical columns (14) and horizontal beams (19) are for both original and retrofit building construction. The SMRF connection is a column tree assembly (13) consisting of primary trunk assembly (17) engaging secondary branch assembly (18). Primary trunk assembly (17) has vertical parallel gusset plates (25, 26) secured to vertical column (14) with flanges (27) at each beam-to-column joint location, and base plates (28) at one end of the column and a splice (33) at the other end. Secondary branch assembly (18) is secured normal to primary trunk assembly (17) between parallel gusset plates (25, 26). Secondary branch assembly (18) includes stub beam section (30) fitted with shear transfer plates (32) secured to the web of stub beam section (30) and to parallel gusset plates (25, 26). Plate (28) is secured to each flange of the stub beam (30) and parallel gusset plates (25, 26) to bridge the gap (31). Vertical shear tab plate (32) is secured to the web of stub beam (30).

Coplanar waveguide bandpass filter-a ribbon-of-brick-wall design

Abstract: This paper proposes a novel ribbon-of-brick-wall design of the coplanar waveguide bandpass filter which is built from cascading several sections of quarter wavelength open-end series stubs. The design originates from modeling the series stub as a system of two asymmetrically coupled transmission lines, which is then made equivalent to a basic filter element of admittance inverter. The relationship between the parameters of the coupled transmission lines and the admittance inverter is derived and the design charts are provided for the convenience of the designers. Systematic procedure is established to design the Chebyshev filter, which is also fabricated and measured. In addition, the quasistatic equivalent lumped circuit models of the discontinuities formed between two sections are evaluated and incorporated into the circuit simulation to get better prediction for the filter performance. The good agreement between simulation results and experimental data justifies the design procedure and validates the present analysis approach. >

Patch antenna assembly

Abstract: A laminar patch antenna comprises a ground plane element with a cross shaped aperture sandwiched between two dielectric layers with a patch radiator on one dielectric layer and a transmission line circuit on the other dielectric layer. The transmission line circuit has linear conductors overlying respective sectors between slots of the aperture, the conductors providing a feedline and stub projection with lines of similar type overlying opposite sectors of the cross and conductors of different type overlying adjacent sectors of the cross.

Miniature stub and filter designs using the microshield transmission line

Abstract: This paper presents new CPW-type stub and filter configurations which are useful approaches for compact microwave circuit design. It is shown that conventional open- and short-end quarter wavelength stubs can be shortened by a factor of three by folding the center conductor. Also, narrowband open-end stubs are demonstrated which have thin-film overlay capacitors integrated across the stub sections. In this work the circuits have been implemented using the microshield transmission line, a geometry in which a 1.4 /spl mu/m-thick dielectric membrane supports coplanar conducting lines virtually in free-space. The new stub configurations, however, are also suitable for standard substrate-supported CPW. >

New technique to measure transmission line attenuation

Abstract: A new technique using a quarter-wave open stub resonator was developed to measure a transmission line's attenuation coefficient. Transmission line attenuation was extracted from the Q-factor measurement of the open stub resonator. Equations were derived that relate the stub's two port S-parameters to transmission line attenuation. The new method's benefits include higher accuracy over other methods of attenuation measurement, less area required for the test structure, and easier test structure design. Applications include simple and accurate determination of the transmission line's loss characteristics and effective dielectric constant at very high frequencies. >

FM-CW radar transceiver

Abstract: An FM-CW radar transceiver comprising an oscillator connected to an input of a power divider having first and second terminal outputs. The first terminal output of the power divider is connected to an input of a first diode and a first shorted stub. The second terminal output of the power divider is connected to an input of a phase shifter with the output of the phase shifter connected to an input of a second diode and a second shorted stub. The outputs of the first and second diodes are each connected to inputs of first and second intermediate frequency (IF) filters and then through first and second IF blocking structures terminating at a common antenna port. An open stub is connected to the common antenna port with the outputs of the first and second IF filters each connected to an IF port or channel. In use, the FM-CW transceiver operates as a frequency multiplier for transmitting, and simultaneously as a subharmonically pumped "I/Q" mixer for reception.

Fuel injection valve

Abstract: In fuel injection valves which are already known, fuel filters are press-fitted into a fuel inlet stub and thereby fixed therein. This method of fixing gives rise to the risk of abraded particles and shavings, which can lead to malfunctioning of the fuel injection valve. In addition, holding collars for upper sealing rings are designed as separate components. The new fuel injection valve has a fuel filter (61) which is of one-piece configuration with a holding collar (60). The holding collar (60) extends radially beyond the fuel inlet stub (2) and has a protruberance (65) outside the fuel inlet stub (2). Together with the groove (66) on the outer circumference of the fuel inlet stub (2), the encircling protuberance (65) on the holding collar (60) forms a snap-in connection by means of which the fuel filter (61) is fixed in a defined manner. Between the main body (67) of the fuel filter (61) and the inner wall of the fuel inlet stub (2) there is only a clearance fit and any formation of shavings in the interior of the fuel injection valve is thus avoided. The fuel injection valve is suitable, in particular, for use in fuel injection systems of spark-ignition engines.

Adjustable monitor support assembly

Abstract: An adjustable monitor support assembly for a monitor is positioned under a transparent portion in the top surface member of a desk-like structure. The support assembly utilizes a shelf member that is supported by laterally outwardly extending associated stub shafts. A pair of rails is provided and each one thereof is located along a different lateral side of the shelf member. The stub shafts slidably engage the rails so that the shelf member is movable relative to the rails. Retaining members for holding the shelf member at a desired location along the rails are provided. Since the rails are parabolically curved, the monitor is movable with the front face being generally perpendicular to the eye levels of various seated users.

Tunable dual and triple frequency stub loaded rectangular microstrip antennas

Abstract: Dual band printed microstrip antennas using single layer and multilayer patches have been reported. Triple band performance has been reported for a square patch antenna using a spurline filter and the perturbation technique. This paper proposes the concept of tunable dual and triple band microstrip antennas with nearly quarter wavelength monolithic stubs loaded at the radiating edges of the rectangular or square patch.

FDTD modeling of microstrip‐line‐FED wide‐slot antenna

Abstract: Microstrip‐line‐fed wide‐slot antennas of different dimensions are analyzed using the finite‐difference‐time‐domain (FDTD) method. The numerical results are checked against experimental results and reasonable agreement is obtained. The antenna can be matched by adjusting the length of the matching stub. This happens when the trailing edge of the stub is within the width of the slot. In addition, it is found that the impedance bandwidth of the antenna can be improved by widening the slot. © 1995 John Wley & Sons, Inc. Copyright © 1995 Wiley Periodicals, Inc., A Wiley Company

Simulation of HF circuits with FDTD technique including non-ideal lumped elements

Abstract: An extension of the FDTD algorithm is devised, accounting for high-frequency models of lumped elements. Bipolar transistors, junction and Schottky diodes are considered, as well as their associated nonlinear capacitances. Several validation examples are given. In particular, a simple, yet complete, structure has been simulated, consisting of an L-band unbalanced mixer and including a microstrip stub, a microstrip to microstrip tee junction, a microstrip gap and a shielding package. Results favourably compare with alternative simulation techniques. >

Stub loaded microstrip reflectarrays

Abstract: Because of fabrication simplicity, design robustness, and planar form factor, a microstrip reflect array provides an attractive alternative to the common parabolic reflector. This paper discusses the design and analysis of a reflect array utilizing a stub loaded microstrip element as shown. The analytical technique discussed not only provides a theoretical framework for the design of microstrip reflect arrays in general, but also permits the prediction of reflect array performance over extended bandwidths.

LAN star connection using negative impedance for matching

Abstract: An impedance matched branch connection for local area networks (LANs). A stub or branch connection increases the number of computers that can connect to a LAN. A star connection is formed when several stub lines are connected at the same point. Stub connections introduce an impedance discontinuity in the line and this discontinuity causes signal reflections which interfere with normal data transmission. The impedance discontinuity is avoided by providing a negative impedance device at the star point which makes the impedance at each transmission line appear as though the stub lines were not added.

Characteristics of aperture-coupled rectangular dielectric resonator antenna

Abstract: Theoretical analysis of an aperture-coupled rectangular dielectric resonator antenna is presented. A model based on the modal expansion method and the spectral domain approach is developed. Numerical results for return losses and radiation patterns of the TE111y mode are compared with experimental data available in the literature and reasonable agreement between theory and experiment is obtained. This model is flexible as it enables studies to be made of the effects of parameters such as slot dimensions, slot displacement and stub length on input impedances.

The development of an 850 GHz waveguide receiver using tuned sis junctions on 1µm Si 3 N 4 membranes

Abstract: We report preliminary development work on a 850 GHz SIS heterodyne receiver employing a tuned niobium tunnel junction on a 1 µm Si3N4 supporting membrane. Since the mixer is meant to be operated well above the superconducting gap frequency of niobium (2δ/h њ 690 GHz) special care has been taken to minimize transmission line loss. We have therefore used junctions with an integrated radial stub RF matching network to tune out the large shunt susceptance of the junction and minimize the niobium film absorption loss. Scale model measurements of the waveguide embedding impedance have been made to aid in the design of the choke structure and RF matching network. Detailed Fourier Transform Spectrometer measurements of tuned junctions on both SiO2 and silicon nitride membranes show response up to 1100 GHz and indicate that the absorption loss in the niobium film is in the order of 4–7 dB at 850 GHz, in fairly good agreement with the theoretical loss calculated from the Mattis-Bardeen theory. The junctions have a center frequency of 800 GHz which presents a 6% downshift from the designed value.

Exhaust gas recirculation valve for an internal combustion engine

Abstract: An exhaust gas recirculation valve which comprises a stub pipe which protrudes into a pipe and with whose opening a valve element interacts, which valve element is moved by an actuator, the actuator being connected to the stub pipe by means of a connecting part in such a way that the above mentioned parts can be jointly inserted through a first opening into the pipe, a closing part of the stub pipe closing a second opening of the pipe, at which location an outwardly protruding end of the stub pipe is connected to an exhaust gas recirculation conduit. The connecting part advantageously also serves to relay measurements of a measurement recording device, recorded at the stub pipe to the analysis device of the measuring device.

Noise measurements of microwave transistors using an uncalibrated mechanical stub tuner and a built-in reverse six-port reflectometer

Abstract: This paper describes a novel noise parameter measurement technique using a nonrepeatable and uncalibrated mechanical stub tuner and a built-in reverse six-port reflectometer. The main advantages of this approach are: (1) avoiding the use of an automated repeatable mechanical tuner or thermally controlled electronic tuner, (2) the noise and S-parameter characterization of the tuner is not required, (3) the convenience to change the measurement reference plane, without need of further tuner calibration, and (4) the relatively low cost of the test set, compared to a commercial system. Measurements are obtained for the NE 76184 general-purpose GaAs FET and compared to the noise figure calculated using the data provided by the manufacturer for different source impedance values. >

Protective shield for fire hydrant

Abstract: A protective shield for a fire hydrant operating stub is provided which allows direct access to the operating stub by standard authorized tools without requiring the removal of any portion of the shield. The shield includes an inner ring with a peripheral groove which carries a snap ring. A cylindrical outer ring is carried on the snap ring and rotates freely on the snap ring without causing the operating stub to rotate. The outer ring preferably has two recesses formed in its surface to allow placement of authorized tools directly on the operating stub without removing any portion of the shield and the recesses are formed to prevent placement of standard pipe wrenches on the operating stub.

Rectangular microstrip antennas with stub along the non-radiating edge for dual band operation

Abstract: A rectangular microstrip antenna with a half wavelength short circuited stub placed along the radiating edge exhibits dual frequency operation. Dual frequency operation is obtained with quarter wavelength open circuited stubs also. Two unequal stubs of nearly /spl lambda//4 length placed along both the radiating edges yield triple frequency operation. This paper describes the effect of a /spl lambda//4 open ended stub placed along the nonradiating edge of the square or rectangular patches for dual frequency operation. These antennas have been analyzed based on the multiport network model using a segmentation method with the Green's functions approach.

Ballistic electronic stub tuner for potential use in analog‐to‐digital conversion

Abstract: Electron transmission in the fundamental transverse mode of an asymmetric double‐stub electronic stub tuner (ADEST) in the ballistic regime is theoretically shown to be a symmetric, almost sine wavelike, periodic function of an offset parameter d, where d is a measure of the stub asymmetry and is the distance between the lines that bisect the stub and the main wire. The periodic pattern remains quite robust at finite temperatures (≊5 K). This unique multiple folding output characteristic of a single ADEST may conceivably be used for fast, high binary bits analog‐to‐digital conversion.

A CMOS gate array with dynamic-termination GTL I/O circuits

Abstract: A 530 kG gate array with novel GTL I/O circuits has been developed using 0.5 /spl mu/m CMOS triple-metal-layer process technology. The I/O circuit of a push-pull output driver and a dynamic termination receiver can transmit 250 Mb/s data through a long stub line which is connected to a terminated bus line. IDDQ testability is designed for the differential receiver without any delay time overheads.

Antenna for radio equipment

Abstract: PURPOSE: To obtain an inverted-F shaped antenna for a radio equipment which is light and rigid and not breakable by a deep notch and whose resonance frequency is adjusted simply after the manufacturing process. CONSTITUTION: The antenna is made up of a printed circuit board 2 with a radiation element mounted thereon, a spacer 8 used to set the printed circuit board 2 at a prescribed interval in parallel with respect to the ground of a printed circuit board 1 of a portable radio equipment, a feeding point 3 for feeding power to the radiation element, and a short stub 4 interconnecting the ground and the radiation element. The radiation element is made up of a copper foil pattern on which slit patterns 9, 10 are formed to adjust the resonance frequency of the antenna for the radio equipment before and after the manufacture. COPYRIGHT: (C)1996,JPO

Liquid-ring gas pump with a silencing element in the discharge space

Abstract: Disclosed is a liquid-ring gas pump comprising a discharge space, a discharge stub connected to the top of the discharge space, and a removable tubular silencing element having one end extending downwardly through the discharge stub into the discharge space.

Automatic tuning method and device for plasma generating microwave circuit

Abstract: PURPOSE:To perform automatic variable value control on a desired operational condition value by a stub adjuster to drive slidably a directional coupler, an E surface stub and an H surface stub on respective two driving shafts by a motor in a wave guide. CONSTITUTION:The tip surfaces of an E surface stub and an H surface stub are adjusted to the same plane with the inner wall surfaces 6e and 6h (reference surface) of a wave guide 6. A silicon wafer as a dummy or a standard material is inserted as a load in a bell jar 8a of a plasma generating chamber 8. Constant power is made incident on the load from a microwave generator 3. At this time, though incident electric power in the wave guide 6 and load impendance are not adjusted to each other, the incident electric power and reflected electric power are measured by a directional coupler 5, and are sent to a controller through a power meter 9. The controller calculates reflectance, and stores it in respective coordinates on a RAM10b. Only by determining desirable incident electric power and reflectance and setting them in a controller when they are used, the controller tunes them automatically to a vicinity value.

Compact stubs for micromachined coplanar waveguide

Abstract: This paper presents the characteristics of compact stub configurations which are suitable for coplanar waveguide implementation. The motivation behind this work is based on recent results which demonstrate that micromachined, membrane-supported transmission lines are a high-performance medium for microwave and millimeter-wave circuit design. Since the effective permittivity of the substrate is very close to 1, however, circuit dimensions can become relatively large, particularly at the low mm-wave frequencies. It is therefore desirable to reduce the component size, and a technique for accomplishing this with CPW-type series tuning stubs is described herein.

Microwave integrated circuit

Abstract: PURPOSE:To miniaturize a circuit by connecting the microstrip line for the input/output matching circuit to the signal transmission line of an active element, connecting other terminal to the electrode layer of an MIM capacitor and forming a short stub for matching. CONSTITUTION:The source terminal of an active element 1 on a semiconductor substrate is connected to the electrode layer of the surface of the substrate and is electrically connected to the ground electrode on the rear through a via hole 4. On the electrode layer of the surface of the substrate, MIN capacitors 9 and 10 which use the electrode layer as lower part electrode are integrally formed on the via hole 4 and power source lines 7 and 8 for the active element 1 are connected to the upper part electrode (a third electrode layer). Microstrip lines 11 and 12 for input/output matching circuit are connected to the signal transmission lines 2 and 3 of the active element 1; other terminals of these lines 11, 12 are connected to the third electrode layers of the MIM capacitors 9 and 10; and each of short stub for matching is formed. Therefore, the microstrip lines 11 and 12 have both function as the matching circuit and the function as a bias circuit.

Broadband monopole antenna in uniplanar printed circuit technology and transmit- and/or receive device with such an antenna

Abstract: The antenna includes a feed line (2) which is positioned on the first surface of a substrate. A conductor (3) is positioned on the second surface to form a ground plane (4) for the RF feed. A radiating stub (6) extends at least partially along the length of the side of the ground plate. A coupling slot (7) is formed between the stub and the plate. The coupling slot crosses the supply line at a crossing point beyond which the supply line has a series stub of a first adaptable length and the slot forms a parallel stub of a second adaptable length. The slot can be rectangular and the stub have variable width.

Efficient material‐gain models for the transmission‐line laser model

Abstract: Transmission-line laser models (TLLMs) are time-domain models suitable for the simulation of complex phenomena in semiconductor lasers. TLLMs include time-domain filters based on transmission-line stubs to model the spectral dependence of the material gain. In this paper, numerical simulations are presented which show that the accuracy of these gain models is dependent on the model's iteration timestep. Analytical formulae are derived that relate the accuracy of the filters to the timestep, filter centre frequency, and filter bandwindth. A new wideband stub filter which allows the material gain to be modelled using a larger timestep is presented. This is equivalent to a digital infinite-impulse-response filter, which is more computationally efficient than finite-impulse-response filters, and is unconditionally stable. The new gain model can improve the computational speed for simulating for multimode Fabry-Perot lasers by a factor of 10–100.