Design optimization for energy-efficient pulse-switching networks in carrier-injection based Si-photonics

We compare pulse-switching operations in MZI- and ring-switches both experimentally and based on large-signal circuit simulations. With a modification in switch design and with optimization of phase modulator lengths, we show high-speed switches with potential for an over 3 dB improvement in energy consumption

Analysis And Design Of Coplanar Waveguide For High-Speed Pulse Propagation On Printed Circuit Board

Tujuan tesis ini adalah untuk menyelidik struktur pandu gelombang sesatah (CPW) yang sesuai bagi kegunaan papan litar (PCB) untuk perambatan dedenyut berkelajuan tinggi, untuk menjalankan kajian menyeluruh mengenai ciri-ciri perambatan dan juga untuk membandingkan keupayaan dengan talian mikrostrip. The goals of this thesis are to investigate a suitable printed circuit board (PCB) coplanar waveguide (CPW) for high-speed signal propagation application, to conduct thorough analyses of its propagation characteristic and to compare its performance against the mainstream microstrip line

Estimating the availability of hydraulic drive systems operating under different functional profiles through simulation

Hydraulic drive systems are widely used in a variety of industrial applications where high torque and low speed rotational power are required. The advantages include maximum torque from zero speed, continuously variable speed within wide limits, high reliability and insensitivity to shock loads. A drive system consists of a hydraulic circuit, electric motors, hydraulic pumps, hydraulic motors and auxiliary components. The stress on the components, and hence wear and failure rate, varies with the torque and speed output by the drive. The reliability of a hydraulic drive system of a particular design can therefore vary significantly between installations operating in applications with different functional requirements. Predicting the availability of a drive system in a particular application is useful for several purposes such as optimising the system design and estimating support costs. This paper describes a simulation model, developed to estimate the availability of a hydraulic drive system in a given functional profile, consisting of output torque and speed time phase requirements. It outputs statistics on system availability and component failure rates. As an example, the simulation model is used to compare these statistics for a drive design operating under two distinct operational profiles

Options for Control of Reactive Power by Distributed Photovoltaic Generators

High penetration levels of distributed photovoltaic(PV) generation on an electrical distribution circuit present several challenges and opportunities for distribution utilities. Rapidly varying irradiance conditions may cause voltage sags and swells that cannot be compensated by slowly responding utility equipment resulting in a degradation of power quality. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We discuss and compare via simulation various design options for control systems to manage the reactive power generated by these inverters. An important design decision that weighs on the speed and quality of communication required is whether the control should be centralized or distributed (i.e. local). In general, we find that local control schemes are capable for maintaining voltage within acceptable bounds. We consider the benefits of choosing different local variables on which to control and how the control system can be continuously tuned between robust voltage control, suitable for daytime operation when circuit conditions can change rapidly, and loss minimization better suited for nighttime operation.Comment: 8 pages, 8 figure

Ancient Vedic Multiplication Based Optimized High Speed Arithmetic Logic

Here, we deal with most effective Vedic multiplication method dependent 4*4 bit arithmetic logic unit having high speed. In this paper, we will perform ALU operations. ALU is a development of research work that has been done for years so we have chosen this topic. Normally ALU is a heart of digital processor, central processing unit, microprocessor and micro controller. Every digital domain based technology has to depend on the performance of ALU. Hence, there is a necessity of ALU which generates high speeds which depends on the speed of multiplier. Therefore, we go for designing a 4-bit multiplier. To generate high speeds, multiplier is employed which is one of the important blocks of the hardware unit and also an important initiation of delay in the path. We have studied many algorithms for multiplication technique but research says that Vedic multiplication is most effective of all in terms of speed. The algorithm contains 16 sutra, out of which we are employing URDHVA TIRYAKBHYAM and the code is written in Very High Speed Integrated Circuit Hardware Description. Our supporting synthesizing and simulating tools are Xilinx ISE9.2i and model sim-altra6.3g-pi (Quartus II) respectively. At last, we will compare 4-bit ALU with 4-bit Array ALU.    &nbsp

Analog Computing for Molecular Dynamics

Modern analog computers are ideally suited to solving large systems of ordinary differential equations at high speed with low energy consumtion and limited accuracy. In this article, we survey N-body physics, applied to a simple water model inspired by force fields which are popular in molecular dynamics. We demonstrate a setup which simulate a single water molecule in time. To the best of our knowledge such a simulation has never been done on analog computers before. Important implementation aspects of the model, such as scaling, data range and circuit design, are highlighted. We also analyze the performance and compare the solution with a numerical approach.Comment: 9 pages, 9 figures, submitted to Emerging Topics in Computing, IEEE Tran

A new robust handshake for asymmetric asynchronous micro-pipelines

[[abstract]]In this paper, a new handshake methodology to enhance the performance of the asynchronous micro-pipeline systems is proposed. The proposed handshake methodology has more flexibilities to design an asymmetric asynchronous micro-pipeline system. The proposed handshake methodology also has some advantages, like latch free, robust, high throughput, very short pre-charge time, less transistors, and more flexibility in asymmetry data path. A technique that combines a single-rail dynamic circuit with a dual-rail dynamic circuit was proposed and used to design in the data path. In the critical delay data paths, the dual-rail dynamic circuits were used to improve the operating speed. Others, the single-rail dynamic circuits were used. It brings some advantages that reduce power consumption and die area while maintaining the calculation speed. An asynchronous micro-pipeline array multiplier was designed and implemented by the new robust handshake methodology. Based on the TSMC 0.35μm CMOS technology, the simulation results show that the proposed new handshake methodology has shortest latency and more robust property as compare with other handshake methodologies.[[conferencetype]]國際[[conferencedate]]20030525~20030528[[booktype]]紙本[[conferencelocation]]Bangkok, Thailan

High-Level Optimization by Combining Retiming and Shannon Decomposition

Applying Shannon decomposition can reshape sequential circuits and improve opportunities for retiming. Both Shannon decomposition and retiming only rely on limited information about combinational blocks (timing estimates), so both techniques are suitable for high-level synthesis. We describe an efficient algorithm to preprocess a circuit using Shannon decomposition to increase retiming efficacy. It assembles complex chains of Shannon decompositions while carefully avoiding parallel ones in order to limit the area overhead due to logic duplication. We compare a traditional retiming flow with the same flow augmented with our algorithm. Although our algorithm provides no improvement on half of our benchmarks, for the other half we obtain a 25% speed-up on average (7% to 61%), while only increasing area by 5% (3% to 12%)

Considerations for Magnetic-Field Coupling Resulting in Radiated EMI

Parasitic inductance in printed circuit board geometries can worsen the EMI performance and signal integrity of high-speed digital designs. Partial-inductance theory is a powerful tool for analyzing inductance issues in signal integrity. However, partial inductances may not adequately model magnetic flux coupling to EMI antennas because the EMI antennas are typically open loops. Therefore, partial inductances may not always accurately predict radiated EMI from noise sources, unless used in a full-wave analysis such as PEEC. Partial inductances can be used, however, to estimate branch inductances, which can be used to predict EMI. This paper presents a method for decomposing loop or self inductances into branch inductances. Experimental as well as analytical investigations are used to compare branch- and partial-inductances