Electronic Devices and Semiconductor Manufacturing Commons^™

Capacitor Voltage Control Techniques Of The Z-Source Inverter: A Comparative Study, Omar Ellabban, Joeri Van Mierlo, Philippe Lataire

Omar Ellabban

The Z-source inverter (ZSI) is a recently proposed single-stage power conversion topology. It adds voltage boost capability for complementing the usual voltage buck operation of a traditional voltage source inverter (VSI) with improved reliability. In this paper, a single-loop and dual-loop capacitor voltage control techniques for the ZSI are digitally designed based on a third order small signal model of the ZSI, implemented using a digital signal processor (DSP) and compared. Simulation and experimental results of a 30 kW ZSI during input voltage changes, load disturbances and steady state operations are presented and compared. The results show that the dual-loop …

Topics On Light-Emitting-Diode Driver Research, Jaber Hasan

Graduate Theses and Dissertations

In this dissertation, light-emitting-diode (LED) drivers are investigated for efficiency issues related to driving Red-Green-Blue (RGB) pixels and multiple LED strings in parallel. A high-efficiency digitally controlled RGB LED driver was designed for driving a 3x3 RGB LED display panel. A multiplexer was used to sense the voltage drop across the current controllers. This driver maintained a minimum drive voltage across the RGB LED pixels required to keep it in regulation leading to a reduction of unwanted power losses in the RGB LED pixels by selecting the minimum drop across the current-controllers as the reference voltage of the digital controller. …

The Development And Packaging Of A High-Density, Three-Phase, Silicon Carbide (Sic) Motor Drive, Jared Hornberger

Graduate Theses and Dissertations

Technology advances within the power electronics field are resulting in systems characterized by higher operating efficiencies, reduced footprint, minimal form factor, and decreasing mass. In particular, these attributes and characteristics are being inserted into numerous consumer applications, such as light-emitting diode lighting, compact fluorescent lighting, smart phones, and tablet PCs, to industrial applications that include hybrid, electric, and plug-in electric vehicles and more electric aircraft. To achieve the increase in energy efficiency and significant reduction in size and mass of these systems, power semiconductor device manufacturers are developing silicon carbide (SiC) semiconductor technology.

In this dissertation, the author discusses the …

Multi-Hole Waveguide Directional Couplers, Mahmoud Moghavvemi, Hossein Ameri Mahabadi, Farhang Alijani

Hossein Ameri Mahabadi

1. Introduction The directional couplers are inherently assumed as four-port devices, which consisted of two transmission lines that are electromagnetically coupled to each other. The first port is named as input, and the second one as output or transmitted, the third one as sampling or coupled and the fourth one as isolated or terminated. By using a special design the input power is divided between output and coupled port in a certain ratio named coupling factor. The required value for coupling factor P1/P3 defines the range of applications for directional couplers. Based on the application, coupling factor could be any …

Is Tech M&A Value-Additive?, Ani Deshmukh

Undergraduate Economic Review

Given rising M&A deal volume across all high-tech subsectors, the ability to measure post-acquisition performance becomes critical. Despite this growth, the relevant academic literature is severely lacking (Kohers and Kohers 2000). Using an event-study approach, I find that acquirers and targets both realize statistically significant day-0 abnormal returns (1.23% [p<0.1] and 8.1% [p<0.01], respectively). As positive stock returns signal positive growth prospects in a semi-strong efficient market, AR regressions found that firms' technological relatedness, deal financing, purchase price premiums, and the relative book to market ratio, explained most variance. Overall, high-tech transactions are value-additive for both targets and acquirers.

Recovery Time Of The Schottky-Pin Limiter, Chin-Leong Lim

Chin-Leong Lim

The Schottky-PIN limiter has a ~8dB lower limiting threshold than the self-biased PIN limiter. Following the cessation of overdrive, the limiter requires some time to return to a low-loss state. This transitory state, which is known as the recovery time or blind/dead time, disrupts communication and causes information loss. Unlike the self-biased PIN limiter, there is a dearth of information pertaining to the recovery time of the PIN-Schottky limiter. This work characterizes the most popular form of the PIN-Schottky limiter and also proposes a simple modification to speed up its recovery time. We measured recovery times of >2000uS and 130uS …

Reduce Losses In Rf Schottky-Pin Limiter Circuits, Chin-Leong Lim

Chin-Leong Lim

Limiters can protect wireless receivers from physical damage and information loss. The Schottky-PIN limiter is especially protective because its limiting threshold is ~10dB lower than that of the self-biased PIN limiter. Unfortunately, the limiter diodes have parasitic capacitances that create insertion loss. Moreover, the extra diode in the Schottky-PIN limiter increases its loss over that of the PIN diode-only limiter. Techniques to minimize the parasitic capacitances include using bare chip, air cavity packaging, diode stacking, mesa construction, isolating the Schottky diode from the signal path and connecting the diodes to a low impedance node. But the aforementioned techniques either sacrifice …

Speed Sensorless Torque Control Of An Ipmsm Drive With Online Stator Resistance Estimation Using Reduced Order Ekf, Emad Gameil Shehata E. G. Shehata

Emad Gameil Shehata E. G. Shehata

Speed sensorless control of an interior permanent magnet synchronous motor (IPMSM) based on direct torque control (DTC) is proposed in this paper. The rotor speed and position of the IPMSM are estimated based on an active flux concept, where, the active flux vector position is identical to the rotor position. The proposed algorithm does not require neither high frequency injection signal nor complicated schemes even at vary low speed operation. Torque/ flux sliding mode controller (SMC) combined with space vector modulation is proposed to improve the performance of the classical DTC. Stator resistance value is required for a stator flux …

Digital Control Of Three Phase Three-Stage Hybrid Multilevel Inverter, Saad Mekhilef

Saad Mekhilef

Three-stage 18-level hybrid inverter design with novel control method is presented. The inverter consists of main high-, medium-, and low-voltage stages connected in series from the output side. The high-voltage stage is a three-phase, six-switch conventional subinverter. Themedium- and low-voltage stages are made of three-level subinverters constructed by H-bridge units. The proposed control strategy assumes a reference input voltage vector and aims to approximate it to the nearest inverter vector. The control concept is based on holding the high-voltage state as long as it is feasible to do so. The reference voltage vector has been represented in a 60 -spaced …

Vacuum Microelectronic Integrated Differential Amplifier, S. Hsu, W. Kang, J. Davidson, J. Huang, David Kerns, Jr.

David V. Kerns

Reported is a novel vacuum field emission transistor (VFET) differential amplifier (diff-amp) utilising nanocrystalline diamond emitters with self-aligned gate partitions. The integrated VFET diff-amp was fabricated by a dual-mask self-aligned mould transfer method in conjunction with chemical vapour deposited nanodiamond. Identical pairs of devices with well-matched field emission transistor characteristics were obtained, realising a negligible common-mode gain, high differential-mode gain, and large common-mode rejection ratio (CMRR) of 55 dB. The emission current was validated by a modified Fowler-Nordheim equation in transistor configuration, and the CMRR was modelled by an equivalent half-circuit with the calculated result found to agree well with …

Free Standing Gan Nano Membrane By Laser Liftoff Method, Liang Tang, Yuefeng Wang, Gary Cheng, Michael Manfra, Timothy Sands

Yuefeng Wang

In this work, we present a method able to fabricate thin GaN nanomembranes fit for device applications. Starting from commercial GaN on sapphire substrates, MBE was used to deposit a sacrificial layer, which comprises of a superlattice of InN/InGaN, after which thin a GaN film of hundreds of nanometers thickness was grown on top. Pulsed laser irridiation with photon energy of 2.3eV gives rise to the controlled decomposition of the sacrificial intermediate layer, which can be followed by easy separation of the top GaN membrane from the substrate. This process can be used to manufacture GaN membranes with low defect …

Modeling Of Power Semiconductor Devices, Tanya Kirilova Gachovska

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

One of the requirements for choosing a proper power electronic device for a converter is that it must possess a low specific on-resistance. The specific on-resistance of a bipolar device is related to the base width and doping concentration of the lightly doped drift region. This means that the doping concentration and the width of the low-doped base region in a bipolar device must be carefully considered to achieve a desired avalanche breakdown voltage and on-resistance. In order to determine the technological parameters of a semiconductor device, a one dimensional analysis is used to calculate the minimum depletion layer width, …

Terahertz And Microwave Detection Using Metallic Single Wall Carbon Nanotubes, Enrique Carrion

Enrique A Carrion

Carbon nanotubes (CNTs) are promising nanomaterials for high frequency applications due to their unique physical characteristics. CNTs have a low heat capacity, low intrinsic capacitance, and incredibly fast thermal time constants. They can also exhibit ballistic transport at low bias, for both phonons and electrons, as evident by their fairly long mean free paths. However, despite the great potential they present, the RF behavior of these nanostructures is not completely understood. In order to explore this high frequency regime we studied the microwave (MW) and terahertz (THz) response of individual and bundled single wall nanotube based devices. This thesis is …

Characterization And Implementation Of An Injection Locked Frequency Divider Based On Relaxation Oscillator, Kai Zhu

Doctoral Dissertations

There has been a dramatic increase in wireless awareness among the user community in the past few years. As the wireless communication devices require more integration in terms of both hardware and software, the low-power integrated circuit (IC) solution has gained higher dedication and will dominate in the future radio-frequency IC (RFIC) design. Complementary Metal-Oxide Semiconductor (CMOS) process is extremely attractive for such applications because of its low cost and the possibility to integrate baseband and high frequency circuits on the same chip. The transceiver is often the most power-hungry block in a wireless communication system. The frequency divider (prescaler) …

Cmos Characterization, Modeling, And Circuit Design In The Presence Of Random Local Variation, Benjamin A. Millemon Sr.

Boise State University Theses and Dissertations

Random local variation in CMOS transistors complicates characterization procedures, modeling efforts, simulation tools, and circuit design methodologies in highly scaled CMOS devices. Mismatch is not only a concern for closely matched device pairs in analog circuits; digital circuit designers also have to consider the effects of random variation. Device characterization, modeling, process development, and circuit design engineers have to work together to mitigate the impact of random local variation. This thesis outlines the primary challenges of CMOS characterization, modeling, and circuit design in the presence of random local variation and offers guidelines and solutions to help mitigate and model the …

Fabrication And Characterization Of Thermomechanically Processed Sulfur And Boron Doped Amorphous Carbon Films, Lonnie Carlson

Department of Chemical and Biomolecular Engineering: Theses and Student Research

Small scale, high power density, reliable, and long-life power supplies would be useful or even critical for space missions or the growing number of microdetectors, microsensors, and miniature vehicles. Alpha or beta particle voltaic devices could satisfy these requirements but have been shown to degrade quickly due to radiation damage. Amorphous carbon (a-C) PN junctions or PIN devices could provide radiation hardness and sufficiently high efficiency. As the range of alpha and beta particles in a-C is ~20-120μm, much thicker films than are typical are needed to maximize collection of the particle energy.

In this work, the fabrication of thermomechanically …

Delay Insensitive Ternary Logic Utilizing Cmos And Cntfet, Ravi Sankar Parameswaran Nair

Graduate Theses and Dissertations

As digital circuit design continues to evolve due to progress of semiconductor processes well into the sub 100nm range, clocked architectures face limitations in a number of cases where clockless asynchronous architectures require substantially less power, generate less noise, and produce less electromagnetic interference (EMI). This dissertation develops the Delay Insensitive Ternary Logic (DITL) asynchronous design paradigm that combines the designs aspects of similar Dual-Rail asynchronous paradigms and Boolean logic to create a single wire per bit, three voltage signaling and logic scheme.

DITL is designed at the transistor level using multi-threshold CMOS and carbon nanotube (CNT) FETs to develop …

A Silicon Carbide Linear Voltage Regulator For High Temperature Applications, Javier Antonio Valle Mayorga

Graduate Theses and Dissertations

Current market demands have pushed the capabilities of silicon to the edge. High temperature and high power applications require a semiconductor device to operate reliably in very harsh environments. This situation has awakened interests in other types of semiconductors, usually with a higher bandgap than silicon's, as the next venue for the fabrication of integrated circuits (IC) and power devices. Silicon Carbide (SiC) has so far proven to be one of the best options in the power devices field.

This dissertation presents the first attempt to fabricate a SiC linear voltage regulator. This circuit would provide a power management option …

Investigations Of Conduction Mechanisms Of Ion-Conducting, Bridging Memory Devices (Cbram/Pmc/Ecm), Kyle Bradley Campbell

Boise State University Theses and Dissertations

Electron storage memory devices are approaching the minimum dimensions that are physically possible due to the onward march of Moore’s law. To continue to enable the increased memory densities needed for today’s applications, especially low power and size constrained mobile devices, new memory solutions are needed. Several candidates are emerging in this space. Metal ion-conducting memory devices are being investigated due to excellent scalability, speed, and low power. These devices are part of a memory class called resistive memory. In the literature, they are referred to as CBRAM (conductive bridge random access memory), PMC (programmable metallization cell), ECM (electrochemical metallization …

Power Mems And Microengines, Alan Epstein, Stephen Senturia, G. Ananthasuresh, Arturo Ayon, Kenneth Breuer, Kuo-Shen Chen, Fredric Ehrich, Gautam Gauba, Reza Ghodssi, C. Groshenry, Stuart Jacobson, Jeffrey Lang, Chuang-Chia Lin, Amit Mehra, José Oscar Mur-Miranda, Steve Nagle, D. Orr, Ed Piekos, Martin Schmidt, Gregory Shirley, Mark Spearing, Choon Tan, Sheng-Yang Tzeng, Ian Waitz

José Oscar Mur-Miranda

MIT is developing a MEMS-based gas turbine generator. Based on high speed rotating machinery, this 1 cm diameter by 3 mm thick SiC heat engine is designed to produce 10-20 W of electric power while consuming 10 grams/hr of H2. Later versions may produce up to 100 W using hydrocarbon fuels. The combustor is now operating and an 80 W micro-turbine has been fabricated and is being tested. This engine can be considered the first of a new class of MEMS device, power MEMS, which are heat engines operating at power densities similar to those of the best large scale …