Showing papers on "Decoupling (electronics) published in 2015"

The decomposition of energy-related carbon emission and its decoupling with economic growth in China

Abstract: In order to find the efficient ways to reduce carbon emission intensity in China, we utilize the LMDI method to decompose the changes of China׳s carbon emissions and carbon emission intensity from 1996 to 2010, from the perspectives of energy sources and industrial structure respectively. Then we introduce the decoupling index to analyze the decoupling relationship between carbon emissions and economic growth in China. The results indicate that, on the one hand, economic growth appeared as the main driver of carbon emissions increase in the past decades, while the decrease of energy intensity and the cleaning of final energy consumption structure played significant roles in curbing carbon emissions; meanwhile, the secondary industry proved the principal source of carbon emissions reduction among the three industries and had relatively higher potential. On the other hand, when the decoupling relationship is considered, most years during the study period saw the relative decoupling effect between carbon emissions and economic growth, which indicated that the reduction effect of inhibiting factors of carbon emissions was less than the driving effect of economic growth, and the economy grew with increased carbon emissions; there appeared the absolute decoupling effect in 1997, 2000 and 2001, which implied that the economy grew while carbon emissions decreased; whereas no decoupling effect was identified in 2003 and 2004.

Decoupling of Fluctuating Power in Single-Phase Systems Through a Symmetrical Half-Bridge Circuit

Abstract: Single-phase ac/dc or dc/ac systems are inherently subject to the harmonic disturbance that is caused by the well-known double-line frequency ripple power. This issue can be eased through the installation of bulky electrolytic capacitors in the dc link. Unfortunately, such passive filtering approach may inevitably lead to low power density and limited system lifetime. An alternative approach is to use active power decoupling so that the ripple power can be diverted into other energy storage devices to gain an improved system performance. Nevertheless, all existing active methods have to introduce extra energy storage elements, either inductors or film capacitors in the system to store the ripple power, and this again leads to increased component costs. In view of this, this paper presents a symmetrical half-bridge circuit which utilizes the dc-link capacitors to absorb the ripple power, and the only additional components are a pair of switches and a small filtering inductor. A design example is presented and the proposed circuit concept is also verified with simulation and experimental results. It shows that at least ten times capacitance reduction can be achieved with the proposed active power decoupling method, and both the input current and output voltage of the converter can be well regulated even when very small dc-link capacitors are employed.

Power Decoupling Method for Single-Phase H-Bridge Inverters With No Additional Power Electronics

Abstract: An active method for double-frequency power ripple decoupling in single-phase inverters is presented in this paper, exhibiting the main advantage of not using additional power semiconductors besides the H-bridge. The proposed method requires only two capacitors placed between the midpoint and one end of each inverter leg. An original control solution of the inverter ensures the power ripple transfer toward the two decoupling capacitors without affecting the inverter output voltage. The simple design makes the proposed solution easy to adapt for single-phase inverters in H-bridge configuration. This paper focuses on the autonomous operation mode of the inverter, detailing its operating principle and the control analysis. The system performances, including the impact of the decoupling circuit on the inverter efficiency, are assessed by means of experimental results.

A Dual-Band Coupled Resonator Decoupling Network for Two Coupled Antennas

Abstract: A new decoupling scheme called dual-band coupled resonator decoupling network (CRDN) is presented. By properly designing the coupling coefficients between two pairs of coupled resonators, the network can effectively reduce the mutual couplings between two coupled dual-band antennas in two bands simultaneously. The new scheme is proved by a practical microstrip version of the device for two dual-band antennas working at 2.4 and 5.2 GHz frequency bands. A compact planar dual-band CRDN consisting of a pair of dual-band open-loop square ring resonators is proposed. The measured scattering parameters of two coupled antennas with and without the dual-band CRDN in free space (FS) and with hand phantom demonstrate that the isolation between the two antennas in both the low and high bands can be improved from 8 to 10 dB, respectively, to below 20 dB while maintaining a good matching performance. The total efficiency and envelop correlation coefficient for the decoupled antennas show a significant improvement as compared to the coupled antenna case. The proposed dual-band CRDN scheme is easy to be implemented in an integrated device, and is very attractive for practical multiple input and multiple output (MIMO) applications.

A Component-Minimized Single-Phase Active Power Decoupling Circuit With Reduced Current Stress to Semiconductor Switches

Abstract: This letter proposes a novel circuit topology which can realize the power decoupling function without adding additional active switches into the circuit. The dc-link capacitor of a full bridge rectifier is split into two identical parts and the midpoint is connected to one leg through a filter inductor. With such a configuration, this leg can control the current going into the two output capacitors connected in series for power decoupling, and the other leg can control the line current according to active and reactive power requirement. The proposed topology does not require additional passive component, e.g., inductors or film capacitors for ripple energy storage because this task can be accomplished by the dc-link capacitors, and therefore its implementation cost can be minimized. Another unique feature of the proposed topology is that the current stress of power semiconductors can be reduced as compared to other existing active power decoupling circuits. This feature becomes more obvious when the converter operates with capacitive load, e.g., for grid voltage support. The operational principle of the proposed circuit is discussed, and experimental results are presented to show the effectiveness of the proposed circuit concept.

Wide-Angle Scanning Phased Array Using an Efficient Decoupling Network

Abstract: The active impedance of each element in a phased array changes substantially with scan angle due to mutual coupling. Therefore, a key challenge in the design of wide-angle scanning phased array is to achieve wide-angle impedance matching (WAIM). In this communication, an efficient decoupling network is developed to reduce the mutual coupling between adjacent elements for this purpose. A complete scattering matrix analysis of the decoupling network is given and the design procedure is summarized. A ${1} \times {16}$ linear microstrip phased array has been designed and fabricated for experimental verification. Good agreement is obtained between measured and simulated results. The measured mutual coupling between adjacent elements is reduced to lower than $- {35}\; \text{dB}$ at the center frequency. Due to the reduced mutual coupling, the array can experimentally scan to 66° with a gain reduction of only 3.04 dB.

Robust dynamical decoupling sequences for individual-nuclear-spin addressing

Abstract: We propose the use of non-equally-spaced decoupling pulses for high-resolution selective addressing of nuclear spins by a quantum sensor. The analytical model of the basic operating principle is supplemented by detailed numerical studies that demonstrate the high degree of selectivity and the robustness against static and dynamic control-field errors of this scheme. We exemplify our protocol with a nitrogen-vacancy-center-based sensor to demonstrate that it enables the identification of individual nuclear spins that form part of a large spin ensemble.

An Efficient Decoupling Feeding Network for Microstrip Antenna Array

Abstract: An efficient decoupling feeding network is proposed in this letter. It is composed of two directional couplers and two sections of transmission line for connection use. By connecting the two couplers, an indirect coupling with controlled magnitude and phase is introduced, which can be used to cancel out the direct coupling caused by space waves and surface waves between array elements. To demonstrate the method, a two-element microstrip antenna array with the proposed network has been designed, fabricated and measured. Both simulated and measured results have simultaneously proved that the proposed method presents excellent decoupling performance. The measured mutual coupling can be reduced to below $-58 ~\hbox{dB}$ at center frequency. Meanwhile it has little influence on return loss and radiation patterns. The decoupling mechanism is simple and straightforward which can be easily applied in phased array antennas and MIMO systems.

Decomposing the decoupling indicator between the economic growth and energy consumption in China

Abstract: The decoupling theory is an appropriate tool to study the relationship between economic growth and energy consumption (or environment pollution) But the underlying causes of the states of decoupling are difficult to find Based on the Log–Mean Divisia Index (LMDI) theory, this paper provides a new way to find the nature of the factors governing the changes in the state of decoupling between the economic growth and energy consumption in China Our results show that only four states of decoupling occurred during the period 1991–2012: weak decoupling, expansive coupling, expansive negative decoupling, and strong decoupling The economic activity effect made a negative impact on the decoupling in the study period The energy intensity effect played a positive role in the development of decoupling except in 2003, 2004, and 2008 The economic structure effect only played a positive role in the development of decoupling in several years However, the energy structure effect plays a relative small role in the development of decoupling

Power decoupling techniques for single-phase power electronics systems — An overview

Abstract: The well-known double line frequency ripple power is a critical issue for single-phase power electronics systems, because it may lead to reduced system reliability and efficiency in many applications, e.g. photovoltaic (PV), light-emitting-diode (LED), fuel cell, and battery charger systems. In this paper, recently proposed state-of-the-art power decoupling techniques for ripple power reduction in these systems are presented and classified into different groups for performance comparison. The pros and cons of these techniques are discussed and identified, and the conclusions drawn will be useful for choosing suitable power decoupling topologies and control algorithms according to specific applications from a practical point of view. The future development trends and potentials on this research topic are also discussed.

Decoupling between the Interfacial and Core Molecular Dynamics of Salol in 2D Confinement

Abstract: Dielectric spectroscopy and differential scanning calorimetry (DSC) were applied to study the molecular dynamics and thermal properties of a low-molecular-weight glass-forming liquid, salol (phenyl...

An LTCC Coupled Resonator Decoupling Network for Two Antennas

Abstract: An integrated low-temperature co-fired ceramic (LTCC) coupled resonator decoupling network (CRDN) for two coupled antennas is proposed in this paper By virtue of LTCC technology, a second-order CRDN is realized by two tightly coupled lumped-element resonators in a volume of ${\hbox{32}}\times {\hbox{25}}\times {\hbox{12}}\ {\hbox{mm}}^{3}$ Theoretical analysis has revealed that a wide range of mutual admittance of a CRDN can be realized by choosing appropriate I/O coupling elements while the coupled resonators can be consolidated in an LTCC device This “one-fit-all” feature allows for decoupling a wide range of coupled antennas with different form factors for a given frequency band To prove the concept, two LTCC CRDNs for decoupling different forms of antennas working in the 245-GHz band are designed, fabricated, and tested Measurement results have demonstrated that significant improvement in isolation can be achieved within a wide operating frequency range in all cases The presented design theory and circuit topology are general and can be applied to both symmetric and asymmetric two-element antenna arrays

A novel flexure-based vertical nanopositioning stage with large travel range

Abstract: This paper presents the design of a novel flexure-based vertical (or Z-axis) nanopositioning stage driven by a piezoelectric actuator (PZT), which is capable of executing large travel range. The proposed stage consists mainly of a hybrid displacement amplification mechanism (DAM), a motion guiding mechanism, and a decoupling mechanism. The hybrid DAM with amplification ratio of 12.1 is developed to transfer the transverse motion of the PZT actuator into the vertical motion. The motion guiding mechanism is introduced to avoid cross coupling at the output end. The decoupling mechanism can significantly reduce the cross coupling at the driving end to protect the PZT. The stiffness and dynamics of the proposed stage are improved by these mechanisms. Analytical modeling and finite element analysis (FEA) are then adopted to optimize dimensions of the stage. Finally, a prototype of the stage is fabricated and tested for verification. The results of static and dynamic tests show that the proposed stage is capable of vertical travel range of 214 μm with resolution of 8 nm, and the first two resonance frequencies are 205 Hz and 1206 Hz, respectively. Cross coupling tests under various lateral loads (0 g-1000 g) show that the maximum variances of the lateral and angular cross couplings are less than 0.78 μm and 95 μrad, respectively, indicating good decoupling capability. In addition, the low-profile structure of the stage is well suited to be used in limited vertical space.

An inverse Prandtl–Ishlinskii model based decoupling control methodology for a 3-DOF flexure-based mechanism

Abstract: A modified Prandtl–Ishlinskii (P–I) hysteresis model is developed to form the feedforward controller for a 3-DOF flexure-based mechanism. To improve the control accuracy of the P–I hysteresis model, a hybrid structure that includes backlash operators, dead-zone operators and a cubic polynomial function is proposed. Both the rate-dependent hysteresis modeling and adaptive dead-zone thresholds selection method are investigated. System identification was used to obtain the parameters of the newly-developed hysteresis model. Closed-loop control was added to reduce the influence from external disturbances such as vibration and noise, leading to a combined feedforward/feedback control strategy. The cross-axis coupling motion of the 3-DOF flexure-based mechanism has been explored using the established controller. Accordingly, a decoupling feedforward/feedback controller is proposed and implemented to compensate the coupled motion of the moving platform. Experimental tests are reported to examine the tracking capability of the whole system and features of the controller. It is demonstrated that the proposed decoupling control methodology can distinctly reduce the coupling motion of the moving platform and thus improve the positioning accuracy and trajectory tracking capability.

A Self‐Aligned High‐Mobility Graphene Transistor: Decoupling the Channel with Fluorographene to Reduce Scattering

Abstract: The conduction channel of a graphene field-effect transistor (FET) is decoupled from the parasitic charge impurities of the underlying substrate. Fluorographene as a passivation layer is fabricated between the oxide substrate and channel, and a self-aligned gate-terminated FET is also fabricated. This approach significantly reduces the scattering and, as a result, the mobility increases ten fold.

Application of the Optimized Decoupling Methodology for the Construction of a Skeletal Primary Reference Fuel Mechanism Focusing on Engine-Relevant Conditions

Abstract: For the multi-dimensional simulation of the engines with advanced compression-ignition combustion strategies, a practical and robust chemical kinetic mechanism is highly demanded. Decoupling methodology is effective for the construction of skeletal mechanisms for long-chain alkanes. To improve the performance of the decoupling methodology, further improvements are introduced based on recent theoretical and experimental works. The improvements include: (1) updating the H2/O2 sub-mechanism; (2) refining the rate constants in the HCO/CH3/CH2O sub-mechanism; (3) building a new reduced C2 sub-mechanism; and (4) improving the large-molecule sub-mechanism. With the improved decoupling methodology, a skeletal primary reference fuel (PRF) mechanism is developed. The mechanism is validated against the experimental data in shock tubes, jet-stirred reactors, premixed and counterflow flames for various PRF fuels covering the temperature range of 500–1450 K, the pressure range of 1–55 atm, and the equivalence ratio range of 0.25¬–1.0. Finally, the skeletal mechanism is coupled with a multi-dimensional computational fluid dynamics model to simulate the combustion and emission characteristics of homogeneous charge compression ignition (HCCI) engines fueled with iso-octane and PRF. Overall, the agreements between the experiment and prediction are satisfactory.

A high-efficiency high energy density buffer architecture for power pulsation decoupling in grid-interfaced converters

Abstract: A high-efficiency high-energy-density buffer architecture is proposed for power pulsation decoupling in power conversion between DC and single phase AC. We present an active decoupling solution that yields improved efficiency and reduced circuit complexity compared to existing solutions. By connecting a buffer converter in series with the main decoupling capacitor, the main capacitor is allowed larger ripple for improved energy utilization (and thus much reduced volume), while the DC bus voltage is maintain close to ripple free. The buffer converter has low voltage stress and is only processing a small fraction of the total power of the entire architecture, allowing a very small active circuit volume and very high system efficiency. A control scheme is proposed to exploit the small remaining bus ripple to compensate the power loss in the power converter and balance the power cycle of the buffer architecture. A 2 kW hardware prototype has been built to demonstrate the benefit of the proposed solution. The hardware prototype achieves 20 times capacitance reduction and 2 times overall volume reduction compared to the conventional passive decoupling solution. An energy density of 110 W/inch3 and an efficiency above 98.7% across a wide load range has been experimentally verified.

Single-phase current source converter with power decoupling capability using a series-connected active buffer

Abstract: This study proposes a new power decoupling circuit applied to the single-phase current source converter (SCSC). Differing from the existing power decoupling technologies, the proposed power decoupling circuit could be viewed as a controlled voltage source in series with the DC inductor, and work with SCSC independently. That facilitates the separate design of the modulation schemes and the control algorithms for the power decoupling circuit and SCSC, and reduces the operation restrictions imposed by requirements. The fundamental principle of the proposed converter is analysed, and the voltage reference requirement for the buffer capacitor is investigated. To guarantee high input current quality of SCSC, a control method, where the input current is treated as a virtual control input, is proposed. Finally the effectiveness of this topology is verified by the simulations and experimental results.

Light-matter decoupling and A2 term detection in superconducting circuits

Abstract: The spontaneous and stimulated emission of a superconducting qubit in the presence of propagating microwaves originates from an effective light-matter interaction that, similarly to the case of the atomic case, can contain a diamagnetic term proportional to the square vector potential A(2). In the present work we prove that an increase in the strength of the diamagnetic term leads to an effective decoupling of the qubit from the electromagnetic field, and that this effect is observable at any range of qubit-photon coupling. To measure this effect we propose to use a transmon suspended over a transmission line, where the relative strength of the A(2) term is controlled by the qubit-line separation. We show that the spontaneous emission rate of the suspended transmon onto the line can, at short distances, increase with such a separation, instead of decreasing.

Decoupled current control and sensor fault detection with second-order sliding mode for induction motor

Abstract: This study proposes a new decoupled control method for induction motor (IM) based on higher order sliding mode (HOSM) controller. The proposed controller serves dual purpose by offering decoupled control and sensor fault detection. In this scheme, the decoupled control of d − q currents does not require the knowledge of the speed. The HOSM controllers play the same role as the compensation voltages produced by a decoupling compensator. From the compensation voltages, the speed can be estimated accurately through algebraic calculations. The estimated and actual speeds are then employed for fault detection algorithm to detect the fault. Simulations on a 1/4-hp three-phase IM in the presence of random measurement noise highlights the performance of the proposed approach for decoupling current control and robust sensor fault detection.

A Hardware-Based Countermeasure to Reduce Side-Channel Leakage: Design, Implementation, and Evaluation

Abstract: Side-channel attacks are one of the major concerns for security-enabled applications as they make use of information leaked by the physical implementation of the underlying cryptographic algorithm. Hence, reducing the side-channel leakage of the circuits realizing the cryptographic primitives is amongst the main goals of circuit designers. In this paper, we present a novel circuit concept, which decouples the main power supply from an internal power supply that is used to drive a single logic gate. The decoupling is done with the help of buffering capacitances integrated into semiconductor. We also introduce—compared to the previously known schemes—an improved decoupling circuit which reduces the crosstalk from the internal to the external power supply. The result of practical side-channel evaluation on a prototype chip fabricated in a 150nm CMOS technology shows a high potential of our proposed technique to reduce the side-channel leakages.

Light-matter decoupling and $A^2$ term detection in superconducting circuits

Abstract: We study the spontaneous emission of a qubit interacting with a one-dimensional waveguide through a realistic minimal-coupling interaction. We show that the diamagnetic term $A^2$ leads to an effective decoupling of a single qubit from the electromagnetic field. This effects is observable at any range of qubit-photon couplings. For this we study a setup consisting of a transmon that is suspended over a transmission line. We prove that the relative strength of the $A^2$ term is controlled with the qubit-line separation and show that, as a consequence, the spontaneous emission rate of the suspended transmon onto the line can increase with such separation, instead of decreasing.

Empirical study on the environmental pressure versus economic growth in China during 1991–2012

Abstract: Since adoption of the policy of reform and opening-up in 1978, China has achieved spectacular success in economic growth, which mainly driven by abundant consumption of natural resources and resulted in serious environmental problems. Based on Emergy approach and Rescaled Range analysis, this paper aims to examine the decoupling condition in economic growth nexus environmental pressure both at specific and aggregate level and track the changing trend and the corresponding socio-economic cost in decoupling process. The results show that: the decoupling performance of waste emission (includes waste water, SO2 and solid waste) is better than energy consumption at a specific level which implies that the policies focused on end-of-pipe treatment has been succeeded in meeting the targets of emission reduction. But at aggregate level, the situation is opposite which suggest that China need more efforts in life-cycle management. The weak decoupling condition of resource use and waste water discharge may continue in the future, so as the strong decoupling condition of SO2 and solid waste, but for the aggregate environmental pressure induced by waste emission, the decoupling performance may be getting worse in the future. The investment cost of decoupling increased, whilst the job-cost of decoupling decreased. The decoupling performance can be influenced by environmental policies substantially, such as the polices of circular economy, rigorous emission reduction and waste recycling which have brought about the strong decoupling of SO2 emission and solid waste discharge from economic growth, whereas the less rigorous policies on resource exploitation and waste water discharge didn’t achieve the same result. Therefore, China needs to intensify the unity among various environmental policies.

Article of Footwear with Decoupled Upper

Abstract: An article of footwear including a connecting member is disclosed. The connecting member provides partial decoupling between the upper and the sole structure. The connecting member can include an upper layer and a lower layer that are attached at a central attachment portion.