Showing papers on "Decoupling (electronics) published in 1992"

Effectiveness of multiple decoupling capacitors

Abstract: The effectiveness of using the parallel combination of large-value and small-value capacitors to increase the frequency coverage of either one and overcome the effect of lead inductance is examined. Computed and experimental results are given that show this scheme is not significantly effective. The improvement at high frequencies is at most 6 dB over the use of only the large-value capacitance. >

Electrical interconnect device with interwoven power and ground lines and capacitive vias

Abstract: The invention relates to an electrical interconnect device with power and ground lines interwoven about signal line layers and capacitive vias between signal layers so as to make efficient use of otherwise undedicated area between signal lines and signal layers and to reduce or eliminate the need for separate power and ground layers while providing decoupling capacitance within the wiring structure.

Multiple loop coil with improved decoupling

Abstract: A quadrature coil for receiving NMR signals in magnetic resonance imaging employs as few as two substantially coplanar overlapping loops having sensitivity along perpendicular lines in a region of sensitivity. Each loop is sensitive to a fluctuating uniform magnetic field but is decoupled by a decoupling network. A common ground point shared between the two loops allows the combination of the signals produced by the two loops with a hybrid combiner without the coupling of the loops through the signal's grounds. A third loop may be added to the two loops to produce a third signal to further improve the signal-to-noise ratio of the coil.

Adaptive cross-directional decoupling control systems

Abstract: A method and apparatus for controlling a multiple-input, multiple-output (MIMO) system, such as a sheetmaking system, including identifying a decoupling gain matrix by comparing an actuator control vector against a measured output vector and processing an error vector to update the decoupling gain matrix. The dynamic components of one dynamic mode in the system are separated from that of other dynamic modes such that the input-output characteristic of the process may be treated as independent channels.

Cellular mobile communications antenna

Abstract: A mobile antenna system for use at frequencies in and above the 800 MHz band having a collinear radiator mounted on one surface of a dielectric such as the window of a vehicle. A coupling system is affixed to a second surface of the dielectric. The coupling system includes a counterpoise for coupling RF energy between the radiator and a transmission line connected to a suitable transceiver. Decoupling members connected to the counterpoise minimize coupling of radio frequency energy to defogger wires on the window.

Antenna system for a magnetic resonance imaging tomography apparatus

Abstract: In a magnetic resonance imaging tomography apparatus having a transmission antenna for exciting nuclear spins in an examination subject, and a reception antenna in the form of a local coil, the feeder for the local coil is provided with decoupling elements. The decoupling elements prevent a coupling of the electrical field of the transmission antenna with the feeder for the local coil.

Hydro-elastic engine mount

Abstract: An engine mount for motor vehicles having two enclosed chambers containing hydraulic fluid, which chambers are separated from each other by a partition containing a damping channel passing therethrough to permit hydraulic fluid to flow back and forth between the chambers to damp vibrations imparted to the mount. The engine mount is equipped with a decoupling unit within one of the hydraulic chambers for coupling and decoupling the damping action of the mount in response to varying driving conditions and engine performance. The decoupling unit has a rigid member forming a cavity into which a flexible diaphragm is deflected when vibrations occur when the decoupling unit is set in a decoupling mode to prevent fluid from being pumped back and forth through the damping channel.

A new approach to the decoupling problem of linear time-invariant systems

Abstract: A new approach to the input-output decoupling problem of linear time-invariant systems via proportional state and output feedback is presented. A major feature of the proposed approach is that it reduces the solution of the decoupling problem to that of solving a linear algebraic system of equations. This system of equations greatly facilitates the solution of the following four major aspects of the decoupling problem: necessary and sufficient conditions, general analytical expressions for the controller matrices, general analytical expressions for the diagonal elements of the closed-loop system, and the structural properties of the closed-loop system.

The decoupling of generalized state-space systems via state feedback

Abstract: The input-output decoupling problem of generalized state-space systems (GSS) via proportional state feedback is studied. The following three major issues are resolved: the necessary and sufficient conditions for the problem to have a solution, the general analytical expressions of the controller matrices, and the general analytical expressions of the diagonal elements of the closed-loop system. It is concluded that the approach presented seems to be a quite powerful tool for solving several feedback design problems for GSS systems. Using this method, problems such as decoupling and simultaneous pole assignment and decoupling via output feedback are successfully studied. >

Self protective decoupling capacitor structure

Abstract: An integrated circuit decoupling capacitor is divided into a plurality of discrete segments. The segments are connected electrically in parallel and are redundant to an extent that if one segment (or if desired more than one segment) fails, the remaining segments have sufficient capacitance to provide the required decoupling function. Each decoupling capacitor segment has a fuse connected in series with it. The fuse opens in response to a fault in a decoupling capacitor segment that would otherwise cause that segment to short the power supply to ground.

Some aspects of the energy function approach to angle and voltage stability analysis in power systems

Abstract: Both Angle and voltage stability are discussed in the context of the energy function approach. It is shown that complete decoupling of the two phenomena is not possible in general, particularly in stressed systems. It is demonstrated that the UEP (unstable equilibrium point) concept is a valid one for both types of stability analysis. >

A 6-axes Motion Control Method for Parallel-Linkage-Type Fine Motion Stage.

Abstract: This paper describes a position control method and a control system configuration for newly developed fine motion stage using parallel linkage mechanism. A new static decoupling control method is proposed to compensate interference characteristics of 6-axes stage, including compensation of machine and actuator accuracy. Its decoupling parameters (Jacobian matrix) are calibrated by iterative process, and as a result total decoupling accuracy of 5% is obtained. The control algorithm, which requires complicated matrix calculation, could be executed within 250μs by parallel processing method using multi transputers. By experimental results of step response for each degree of freedom, it is confirmed that proposed decoupling method is more effective than conventional one. Consequently positioning resolution of 0.01μm (x, y), 0.123μrad (θz), response of 30-40 Hz, and dynamic rigidity of more than 12.3 N/μm (x-direction, frequency <40 Hz) are obtained.

Performance characterization of a high power factor power supply with a single power stage

Abstract: A single high-frequency full-bridge power stage produces two outputs. One is connected in series with the rectified AC line to boost the bus voltage, and the other is the desired DC output. The boosting stage, implemented as a series-resonant power converter, is frequency controlled over the 120 Hz cycle to maintain the bus constant at an optimum fraction above the peak line voltage. This provides adequate wave shaping of the line current to maintain the high input power factor. Regulation of the main DC output is achieved by phase shifting the inverter pole voltages. Independent control of the two outputs provides the strong decoupling necessary, and hence good transient response. The soft switching nature of the converter improves performance and allows reduction in size/weight at frequencies in the hundreds of kilohertz. Experimental results show a power factor above 95% from 100% to 20% load, with peak efficiencies in the range of 85-86%. >

Actuation strain decoupling through enhanced directional attachment in plates and aerodynamic surfaces

Abstract: Three methods of decoupling and one method of increasing actuator strain throughenhanced directional attachment (EDA) are presented. Directionally attached piezoelectric(DAP) elements are laminated to an uncoupled plate to generate 44°/m in bending without twistand 31°/m of twist without bending. The strains are enhanced 5 to 12% when the elements aretransversely stiffened. Analytical EDAP models are presented with experiment and theory inclose agreement. A comparison of EDA to current laminating techniques demonstrates 50 to 1000%higher strain rates in twist. Data from a wing using EDAP elements is also briefly summarized.

Combined modal and singular perturbation approach to decentralized control

Abstract: A method is presented for the systematic design of decentralized controllers for large-scale interconnected dynamical systems. The design method employs modal and singular perturbation techniques to affect decoupling of the interconnection into its subsystem components. Once the decoupling is achieved, local controllers for each subsystem are designed individually to place the closed-loop poles of each subsystem in some prespecified locations in the complex plane. The resulting controllers are then used to generate local control inputs, using local information only. A dynamical system comprising four interconnected subsystems is taken as example. Simulation results show that the decentralized controller obtained by the proposed method is comparable to that obtained by conventional global controller design methods.

Globally convergent multivariable adaptive decoupling controller and its application to a binary distillation column

Abstract: This paper describes a new multivariable adaptive decoupling controller combining a decoupling compensator with a generalized minimum variance technique. The controller can completely decouple closed-loop systems both dynamically and in the steady state. It can control an unstable and/or non-minimum phase system and it can control the process with an arbitrary time delay structure. The proof of global convergence for the algorithm is also given. Successful experimental results of the adaptive decoupling control for a pilot-scale binary distillation column demonstrate the effectiveness of the proposed adaptive decoupling algorithm.

Anti-roll mechanism for motor vehicle - uses hydraulic cylinder to connect anti-roll bar to suspension and computer control of coupling between chambers of cylinder

Abstract: The anti-roll mechanism has a hydraulic cylinder connected between the end of the anti-roll bar and an arm of the wheel suspension. The two chambers (16,17) of the cylinder can be interconnected by a hydraulic circuit (25) so that it operates as a damper. A second hydraulic circuit (27) opens or closes under the pressure of fluid in a chamber of the cylinder to ensure return of the piston (15) to a predetermined position. The coupling between the two chambers is controlled by a three-way solenoid valve (23) that is controlled by a computer (32), which operates the valve in response to transverse acceleration, steering angle and speed of rotation of steering wheel, or the speed of the vehicle. ADVANTAGE - Provides automatic 'decoupling' of anti-roll bar to adapt to vehicle operating conditions.

Bilinear Decoupling Control and Its Industrial Application

Abstract: In this paper, the state feedback decoupling control for bilinear systems is discussed. The sufficient condition for the existence of decoupling controller and the design procedure are given. A real world example, the headbox control of a paper machine, demonstrates the efficiency of the proposed method.

Microprocessor for selectively configuring pinout by activating tri-state device to disable internal clock from external pin

Abstract: A microprocessor has a plurality of input/output pins and processing coupled to the input/output pins. Circuitry is provided for selectively decoupling the processing circuitry with one or more of the input/output pins such that pins associated with enhanced features may be decoupled to provide compatibility with a desired microprocessor architecture.

Evidence for aridity-driven dust flux to the northwest Arabian Sea and for decoupling of the dust and upwelling systems

Abstract: Abstract Late Quaternary records of dust grain size, dust flux (mass accumulation rate; MAR) and dust mineralogy from ODP Site 722 on the Owen Ridge, northwest Arabian Sea, have been used to: (1) infer environmental conditions in the continental source areas; (2) determine the spectral response (frequency and phase relationships) of dust MAR and mineralogy to environmental changes associated with global ice volume variations and orbital insolation patterns and (3) evaluate potential associations between the continental (dust) and marine (upwelling) systems over the past 800 ky. The terrigenous dust component is composed of smectite, illite, palygorskite, kaolinite, chlorite, quartz, plagioclase feldspar and dolomite. This is consistent with the composition of source areas currently supplying sediment to the Arabian Sea. An R-mode factor analysis identifies four mineral assemblages: three reflect arid continental source conditions and one reflects more humid conditions. Total dust MAR, two of the three ‘arid’ factor assemblages, and six of the seven minerals associated with the ‘arid’ factors are coherent with the marine isotopic record of global ice volume over at least one primary orbital frequency, with input maxima during glacial (arid) hemicycles. In contrast, wind strength and upwelling intensity indicators exhibit maxima during the interglacial (humid) hemicycles, indicating a decoupling of the continental (dust MAR) and monsoon-driven upwelling systems.