Showing papers on "Stub (electronics) published in 2002"

Transmittivity through straight and stublike waveguides in a two-dimensional phononic crystal

Abstract: We study theoretically the propagation of acoustic waves through a linear waveguide, created inside a two-dimensional phononic crystal, along which a side branch (or stub) is attached The primary effect of this resonatoris to induce zeros of transmission in the transmission spectrum of the perfect waveguide The transmittivity exhibits very narrow dips whose frequencies depend upon the width and the length of the stub When a gap exists in the transmittivity of the perfect waveguide, the stub may also permit selective frequency transmission in this gap We have considered phononic crystals constituted by either fluid or solid constituents The calculations of the band structure and transmittivity are performed by a combination of finite-difference time domain and plane-wave expansion methods

Spin-current modulation and square-wave transmission through periodically stubbed electron waveguides

Abstract: Ballistic spin transport through waveguides, with symmetric or asymmetric double stubs attached to them periodically, is studied systematically in the presence of a weak spin-orbit coupling that makes the electrons precess. By an appropriate choice of the waveguide length and of the stub parameters injected spin-polarized electrons can be blocked completely and the transmission shows a periodic and nearly-square-type behavior, with values 1 and 0, with wide gaps when only one mode is allowed to propagate in the waveguide. A similar behavior is possible for a certain range of the stub parameters even when two modes can propagate in the waveguide and the conductance is doubled. Such a structure is a good candidate for establishing a realistic spin transistor. A further modulation of the spin current can be achieved by inserting defects in a finite-number stub superlattice. Finite-temperature effects on the spin conductance are also considered.

Multifrequency operation of microstrip-fed slot-ring antennas on thin low-dielectric permittivity substrates

Abstract: Operating frequencies and radiation patterns of microstrip-fed ring slot antennas are investigated. The microstrip feed is shown to strongly affect the operating frequencies of the slot antenna. As the length of the microstrip stub is increased to exceed half the guided wavelength of the first operating frequency, then multiple operating frequencies with broadside radiation patterns become available. By extending the single microstrip feed to couple to two slot locations, the antenna's operating frequency ratios and polarizations can be tuned. A number of multifrequency microstrip-fed slot ring antennas are demonstrated. Numerical analysis based on the moment method is compared with the experimental results. A dual-frequency antenna array is also reported.

Asymmetric-element reflect array antenna

Abstract: A reflect array antenna comprises a non-electrically conductive substrate with an array of antenna elements supported on the substrate. Each antenna element comprises a plurality of patch radiating elements arranged in rows and columns. Each patch radiating element comprises a plurality of notches formed in the element, the notches being angularly displaced around the circumference of the element. A plurality of stub short transmission lines are individually positioned in each of the plurality of notches and a plurality of switches individually couple one end of a notch to one of the plurality of stub short transmission lines.

Ballistic spin transport through electronic stub tuners: Spin precession, selection, and square-wave transmission

Abstract: Ballistic spin transport is studied through electronic tuners with double stubs attached to them. The spins precess due to the spin–orbit interaction. Injected polarized spins can exit the structure polarized in the opposite direction. A nearly square-wave spin transmission, with values 1 and 0, can be obtained using a periodic system of symmetric stubs and changing their length or width. The gaps in the transmission can be widened using asymmetric stubs. An additional modulation is obtained upon combining stub structures with different values of the spin–orbit strength.

Ballistic spin transport through electronic stub tuners: spin precession, selection, and square-wave transmission

Abstract: Ballistic spin transport is studied through electronic tuners with double stubs attached to them. The spins precess due to the spin-orbit interaction. Injected polarized spins can exit the structure polarized in the opposite direction. A nearly square-wave spin transmission, with values 1 and 0, can be obtained using a periodic system of symmetric stubs and changing their length or width. The gaps in the transmission can be widened using asymmetric stubs. An additional modulation is obtained upon combining stub structures with different values of the spin-orbit strength.

Pipe screw-connection

Abstract: A pipe screw-connection for connecting a pipeline having a connection end with a deformed annular bead, including a connection stub and a screw-connection coupling part, which can be screw-connected to the connection stub in order to retain the pipeline in a sealed manner is provided The connection stub has an accommodating opening with a radial step surface for axially supporting an end surface of the pipeline and with an inner cone which widens outward away from the step surface The pipeline can be clamped in, by way of the annular bead, with a form fit between the connection stub and a supporting ring, which is seated on the pipeline between the annular bead and the screw-connection part The supporting ring, with the annular bead, forms an abutment surface which is at an angle (α) considerably greater than 45° to the screw-connection axis

The equivalent circuit modeling of defected ground structure with spiral shape

Abstract: We proposed the newly etched DGS (Defected Ground Structure) with a spiral shape in metallic ground plane and the equivalent circuit modeling applied to a spiral DGS for the microstrip line. The proposed spiral DGS can provide steep rejection characteristics with the one and only spiral. The equivalent circuit for the spiral DGS Is derived by means of three-dimensional field analysis methods. To represent spurious resonance, the equivalent circuit of a spiral DGS is consisted of an Inductor and a shorted stub with step impedance. The circuit parameters are extracted from a simple circuit analysis method. Experimental results show excellent agreements with circuit simulation results in wide band and the validity of our circuit modeling for the spiral DGS.

Multiband antenna having reverse-fed pifa

Abstract: A multiband antenna includes a 5-6 GHz PIFA surrounded on two or three sides by a 2.4 GHz RFPIFA. The PIFA and RFPIFA are tunable by removing fingers from the PIFA and either removing portions of or creating at least one area in the RFPIFA where inductance may be added. The RFPIFA contains an inductive meanderline. An out-of-plane matching stub is provided between the feed and the ground plane to impedance match the antenna. The PIFA/RFPIFA is supported by a plastic mesa tabletop whose legs are mounted directly to the ground plane of a PCB at the corner of the PCB. Electronic components on the PCB can be mounted underneath the multiband antenna.

Opening device for can

Abstract: The present invention relates to an opening device for a can, which is constructed such that the contents of the can flow out and exterior air is simultaneously introduced into the can. The opening device of the present invention comprises first and second opening portions 122 and 124 through which the contents flow out and the exterior air is introduced into the can upon opening thereof, respectively, and which are disposed to be opposite to each other at both sides of the top surface 110 of the can and defined by incision lines 122a and 124a so that a part of each of the opening portions is attached to the top surface; and a tab 140 mounted on the top surface of the can by means of a first rivet stub Ra installed outside of the first opening portion and a second rivet stub Rb installed within the second opening portion. The second opening portion is opened while being lifted together with the second rivet stub Rb, the first opening portion is opened while being pressed by a pressing portion 144 around the first rivet stub, and the second rivet stub is formed to be closer to a grip 172 of the tab 170 than the first rivet stub.

Antenna matching circuit

Abstract: A matching circuit for use with radio frequency identification tag antennas configured for modulated backscatter, the circuit including a stub circuit coupled to a detector diode and an antenna and sized and shaped to match a predetermined frequency. The stub circuit is also designed to couple to the antenna such that a resulting phase is seen at the output, preferably 180° from that seen at the input. In addition, the stub circuit is structured to perform as an antenna, thus increasing the sensitivity of the overall circuit and maximizing efficiency and performance.

A dual-L antenna with a novel tuning technique for dual frequency applications

Abstract: A planar dual-L antenna with a novel tuning technique is presented for an integrated GPS/PCS dual-band application. The tuning structure is made of a metal stub attached to one of the shorting plates of the dual-L, antenna, and thus facilitates the independent tuning for lower frequency bands. Simulation and measurements were performed and dual bands of 1565.19 MHz-1585.65 MHz and 1850 MHz-1990 MHz with a return loss better than -10 dB were achieved.

Impedance matching device

Abstract: In an impedance matching device having at least two stubs serially provided to a main coaxial tube so as to be separated from each other with a predetermined interval in a tube axial direction, each stub is composed of a variable capacity capacitor to be jointed to an inner conductor of the main coaxial tube, an electrically conductive capacitor cover to be jointed to an outer conductor of the main coaxial tube so as to cover a surrounding of the variable capacity capacitor, and a drive motor arranged on an outside of the capacitor cover so as to drive a movable side electrode of the variable capacity capacitor. The movable side electrode of the variable capacity capacitor is driven directly by the drive motor so that the impedance matching device is made to be compact and response of impedance matching to a fluctuation of a load impedance such as a behavior of a plasma load is improved, and the life is lengthened and degrees of freedom of installation is widened.

Ferromagnetic composite-based and magnetically-tunable microwave devices

Abstract: This article deals with a new generation of tunable microwave devices using ferromagnetic materials. The sensitivity of the device cut-off frequency to the dc magnetic field was investigated for two filtering resonators (stub resonator and Stepped Impedance Resonator). The stub resonator exhibited a frequency tunability of nearly 40% for a dc magnetic field strength of 250 Oe, whereas the linewidth remained unchanged. A 12.2% tunability of the SIR device was reached under 250 Oe applied.

Device for attachment of an engine onto an aircraft nacelle stub

Abstract: This device is designed to transmit lateral and vertical forces generated by the engine to the nacelle stub ( 10 ), together with the engine torque, and comprises a main attachment structure and an emergency attachment structure ( 38 ). The main attachment structure includes two half-fittings ( 18 a, 18 b ), connecting rods ( 20 a, 20 c ) connecting the two half-fittings to the engine and attachment devices for the half-fittings on the nacelle stub. The emergency attachment structure transmits forces between one of the two half-fittings and the nacelle stub when the other half-fitting or its devices for attachment to the nacelle stub are defective. For example, it comprises a hinge pin ( 42 ) supported by the nacelle stub and passing through a hole ( 44 ) formed in the half-fittings with a clearance.

Optical fiber plug

Abstract: An optical fiber connector plug for an optical fiber connection comprises a connecting portion including a rear entry at a first end and a first fiber stub exit opening to a first fiber stub channel. The first fiber stub exit is parallel to a second fiber stub exit opening to a second fiber stub channel. The first and second fiber stub exits are formed opposite the first end. The rear entry divides at a junction into a first fiber groove and a second, diverging fiber groove. The connecting portion includes crimp elements each having an open-ended bore. Each crimp element contains an optical fiber stub. A molded top attached to the connecting portion includes a substantially rectangular opening. The opening contains a compression element that moves to form splices by capturing a stripped optical fiber and an optical fiber stub in each of the crimp elements. A bend relief boot encloses the connecting portion at one end, while a shroud releasably engages it at the other end.

Spin-depedent transmission of holes through periodically modulated diluted magnetic semiconductor waveguides

Abstract: We study spin transport of holes through stubless or stubbed waveguides modulated periodically by diluted magnetic semiconductor (DMS) sections of width b1 . Injected holes of up (down) spin feel a periodically modulated barrier (well) potential in the DMS sections and have different transmission (T) coefficients. T oscillates with b1 for spin-down and decreases fast for spin-up holes while the relative polarization Pr depends nearly periodically on the stub height. Using asymmetric stubs leads to a nearly square-wave pattern in T and to wide plateaus in Pr . T oscillates with the length between the DMS sections. With two DMS sections per unit, T shows periodically wide gaps for spin-down holes when a DMS width is varied. The results can be used to create efficient spin filters.

Method and structure for stub tunable resonant cavity for photonic crystals

Abstract: Using a micro-electromechanical actuator, tuning stubs may be actuated for tuning cavities in photonic crystal lattice structures. An actuated tuning stub can be used to tune cavities in both two and three dimensional photonic crystal lattice structures

Comparative investigation on numerical de-embedding techniques for equivalent circuit modeling of lumped and distributed microstrip circuits

Abstract: A so-called "short-open calibration" (SOC) technique is applied together with two existing numerical de-embedding techniques for equivalent circuit modeling of microstrip circuits based on a full-wave method-of-moments (MoM) algorithm A stub-loaded microstrip line discontinuity with both electrically short (lumped) and long (distributed) stub lengths is extensively studied in terms of its Z-matrix circuit model Our obtained results show that the SOC scheme allows an accurate calibration of all the potential error terms out of the core circuit network, thereby avoiding numerical noise-related behaviors regardless of either lumped or distributed circuits, which are nevertheless observed for the two existing techniques

Cartridge bearing including a stub shaft and an electrically conductive axle and method of using cartridge bearing

Abstract: The invention is particularly useful for coacting with roller tubes of conveyor apparatus. A cartridge bearing including a stub axle with a tip of greater hardness than the surface circumscribing the aperture receiving the stub axle is inserted into an end of a conveyor roller tube. Along with being electrically conductive, the stub axle can be provided with a damper for reducing vibration. The stub axle engages an electrically conductive stub shaft and moves axially with respect to the stub shaft to operatively interlock with the aperture of the fixed structure. Use of the cartridge bearing provides for the grounding of static charge that can accumulate during operation of conveyor roller tubes.

Microwave measurements of stub tuners in two-dimensional photonic crystal waveguides

Abstract: The transmission spectra of photonic crystal stub-tuned waveguides created in the microwave region are measured. The photonic crystal is a two-dimensional square lattice of dielectric rods. The waveguides are formed by removing rods along a line or by creating a line of coupled cavities. Additional stub-tuning cavities are formed by removing rods or by replacing them with different diameter rods to stub tune the transmission properties of the waveguides. Depending on the cavity geometry, certain wavelengths can be reflected from the stub tuner creating a notch in the waveguide transmission with measured quality factors as high as 488.

Mechanical splice optical fiber connector having a sliding actuator

Abstract: A connector for a fiber optic cable includes: a sliding actuator; an inner housing having a first end and an inner channel, the sliding actuator is engaged with the inner housing; and a ferrule assembly having a first side and a second side, the first side is mounted to the first end of the inner housing, the ferrule assembly includes a fiber stub extending from the second side, the fiber stub extends within the inner channel.

Isolating signal divider/combiner and method of combining signals of first and second frequencies

Abstract: A signal divider/combiner (11) and method combines first and second frequency signals received by microstrip patch antennas (58, 48). A first transmission line stub (28) blocks the second frequency signals on the first signal receiving path, and a second transmission line stub (20) blocks the first frequency signals on the second signal receiving path providing increased signal levels at a receiver input (10). In one embodiment, the transmission line stubs are open-circuit stubs and are positioned a quarter-wavelength from a combining junction (12) formed from stripline transmission lines (14, 32, 50). The transmission line stubs (28, 20) also reduce radiation of the first frequency signal by the second antenna as well as radiation of the second frequency signal by the first antenna. In one embodiment, the first and second frequency signals are the L1 and L2 signals provided by the Global Positioning System.

Optical fiber plug including fiber positioning holder

Abstract: An optical fiber connector plug comprises a connecting portion including a rear entry at a first end and a first fiber stub exit opening to a first fiber stub channel. The first fiber stub exit is parallel to a second fiber stub exit opening to a second fiber stub channel. The first and second fiber stub exits are formed opposite the first end of the connecting portion. An optical fiber connector plug also includes a holder that fits into the rear entry of the connecting portion for permanent retention of at least one stripped, cleaved and polished optical fiber. First and second crimp elements, in the connecting portion, each have an open-ended bore coaxial with the fiber stub channels. Each crimp element contains an optical fiber stub. A molded top attached to the connecting portion includes an opening containing a compression element that forms splices by capturing a stripped, cleaved and polished end portion of an optical fiber and an optical fiber stub in each crimp element. A bend relief boot encloses the connecting portion at one end, while a shroud releasably engages it at the other end.

Low-driving-voltage band-operation LiNbO/sub 3/ modulator with lightwave reflection and double-stub structure

Abstract: A reflection-type Mach-Zehnder LiNbO3 optical modulator with a double-stub structure that can modulate both forward and backward lightwave to achieve low-driving-voltage optical modulation for band-operation is developed. Using optical reflection the modulation efficiency is doubled. The halfwave-voltage of the fabricated modulator was 2.9 V at 7 GHz.

Resonance type optical modulator using symmetric or asymmetric electrode

Abstract: A resonance type optical modulator includes an optical path having electro-optical effect characteristics, a modulation electrode formed along the optical path for applying an electric field to the optical path, a common electrode formed in opposition to the modulation electrode, a feeding line that is connected to the modulation electrode and stubs connected to the feeding line, wherein the feeding line, stubs and common electrode are provided on one side of a region that is divided by the modulation electrode. A specific example is a resonance type optical modulator using a symmetric or an asymmetric electrode, that includes an optical path having electro-optical effect characteristics, a first stub (an open stub) (an open-ended asymmetric coplanar waveguide) or a short stub (a short-ended asymmetric coplanar waveguide), a second stub (an open or short stub) connected to the first stub, a feeding line connected to the first and second stubs and a common electrode, wherein the first and second stubs are formed along a single optical path to comprise a modulation electrode for applying an electric field to the optical path. As a result, the modulator has a configuration easy to fabricate without damaging the effective modulation field strength applied to the optical path, making it possible to realize high modulation efficiency with a low level of electric power.

A frequency-reduction scheme for spiral slot antenna

Abstract: We present a new technique to reduce the initial resonant frequency, enhance the bandwidth, and miniaturize the antenna size for microstrip-feeding spiral slot antennas. Two spiral slot antennas were fabricated and measured to demonstrate the capability of lowering the initial resonant frequency by adding a circular capacitive stub at the end of the feedline. According to results, the initial resonant frequency of the proposed antenna has been shifted from 1.58 to 1.28 GHz; in other words, the antenna size can be reduced by 20%, approximately. The radiation patterns are simulated and measured at 1.3 GHz and 3 GHz to examine the excitation mode. The variations of the initial resonant frequency versus the radius of the circular stub are also shown to find the optimum radius of the stub.

Reflection loss suppression circuit

Abstract: An object is to suppress a reflection loss in any desired frequency band outside a required band, without affecting circuit characteristics in the required frequency band. The output impedance of a circuit in a specified frequency band is transformed into a high impedance by a transmission line 15 . A resistance grounding circuit 18 having a frequency selectivity is connected in parallel. The resistance grounding circuit 18 is constructed of a resistor 16 which has a resistance close to a load resistance, a capacitance C which is selected so as to satisfy an equation Im[tan h{γ(λ/2−δ)}]=−ω 0 CZ 0 at an angular frequency ω 0 included in the frequency band, and a (λ/2−δ)-long end-open stub.