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Full-Text Articles in Engineering
Parallel Recording Of Neurotransmitters Release From Chromaffin Cells Using A 10 X 10 Cmos Ic Potentiostat Array With On-Chip Working Electrodes, Brian Kim, Adam Herbst, Sung Kim, Bradley Minch, Manfred Lindau
Parallel Recording Of Neurotransmitters Release From Chromaffin Cells Using A 10 X 10 Cmos Ic Potentiostat Array With On-Chip Working Electrodes, Brian Kim, Adam Herbst, Sung Kim, Bradley Minch, Manfred Lindau
Bradley Minch
Neurotransmitter release is modulated by many drugs and molecular manipulations. We present an active CMOS-based electrochemical biosensor array with high throughput capability (100 electrodes) for on-chip amperometric measurement of neurotransmitter release. The high-throughput of the biosensor array will accelerate the data collection needed to determine statistical significance of changes produced under varying conditions, from several weeks to a few hours. The biosensor is designed and fabricated using a combination of CMOS integrated circuit (IC) technology and a photolithography process to incorporate platinum working electrodes on-chip. We demonstrate the operation of an electrode array with integrated high-gain potentiostats and output time-division …
Asymptotic Spectral Efficiency Of Multiantenna Links In Wireless Networks With Limited Tx Csi, Siddhartan Govindasamy, Daniel Bliss, David Staelin
Asymptotic Spectral Efficiency Of Multiantenna Links In Wireless Networks With Limited Tx Csi, Siddhartan Govindasamy, Daniel Bliss, David Staelin
Siddhartan Govindasamy
An asymptotic technique is presented for finding the spectral efficiency of multiantenna links in spatially distributed wireless networks where transmitters have channel-state-information (CSI) corresponding to their target receiver. Transmitters are assumed to transmit independent data streams on a limited number of channel modes which limits the rank of transmit covariance matrices. An approximation for the spectral efficiency in the interference-limited regime as a function of link-length, interferer density, number of antennas per receiver and transmitter, number of transmit streams, and path-loss exponent is derived. It is found that targeted-receiver CSI, which can be acquired with low overhead in duplex systems …
A Physical Model For The Kink Effect In Inalas/Ingaas Hemt’S, Mark Somerville, Alexander Ernst, Jesus Del Alamo
A Physical Model For The Kink Effect In Inalas/Ingaas Hemt’S, Mark Somerville, Alexander Ernst, Jesus Del Alamo
Mark Somerville
We present a new model for the the kink effect in InAlAs/InGaAs HEMTs. The model suggests that the kink is due to a threshold voltage shift which arises from a hole pile-up in the extrinsic source and an ensuing charging ofthe surface and/or the buffer-substrate interface. The model captures many of the observed behaviors of the kink, including the kink's dependence on bias, time, temperature, illumination, and device structure. Using the model, we have developed a simple equivalent circuit, which reproduced well the kink's dc characteristics, its time evolution in the nanosecond range, and its dependence on illumination.
Determining Dominant Breakdown Mechanisms In Inp Hemts, Mark Somerville, Chris Putnam, Jesus Del Alamo
Determining Dominant Breakdown Mechanisms In Inp Hemts, Mark Somerville, Chris Putnam, Jesus Del Alamo
Mark Somerville
We present a new technique for determining the dominant breakdown mechanism in InAlAs-InGaAs high-electron mobility transistors. By exploiting both the temperature dependence and the bias dependence of different physical mechanisms, we are able to discriminate impact ionization gate current from tunneling and thermionic field emission gate current in these devices. Our results suggest that the doping level of the supply layers plays a key role in determining the relative importance of these two effects.
Strained Si On Insulator Technology: From Materials To Devices, T. Langdo, M. Currie, Z.-Y. Cheng, J. Fiorenza, M. Erdtmann, G. Braithwaite, C. Leitz, C. Vineis, J. Carlin, A. Lochtefeld, M. Bulsara, Isaac Lauer, Dimitri Antoniadis, Mark Somerville
Strained Si On Insulator Technology: From Materials To Devices, T. Langdo, M. Currie, Z.-Y. Cheng, J. Fiorenza, M. Erdtmann, G. Braithwaite, C. Leitz, C. Vineis, J. Carlin, A. Lochtefeld, M. Bulsara, Isaac Lauer, Dimitri Antoniadis, Mark Somerville
Mark Somerville
SiGe-free strained Si on insulator (SSOI) is a new material system that combines the carrier transport advantages of strained Si with the reduced capacitance and improved scalability of thin film silicon on insulator (SOI). We demonstrate fabrication of 20% Ge equivalent strain level SSOI substrates with Si thicknesses of 100 and 400 Å by hydrogen-induced layer transfer of strained Si layers from high quality graded SiGe virtual substrates. The substrate properties are excellent: wafer scale strained Si film thickness uniformities are better than 8%, strained Si surface roughnesses are better than 0.5 nm RMS, and robust tensile strain levels are …
An Autozeroing Floating-Gate Amplifier, Paul Hasler, Bradley Minch, Chris Diorio
An Autozeroing Floating-Gate Amplifier, Paul Hasler, Bradley Minch, Chris Diorio
Bradley Minch
We have developed a bandpass floating-gate amplifier that uses tunneling and pFET hot-electron injection to set its dc operating point adaptively. Because the hot-electron injection is an inherent part of the pFET's behavior, we obtain this adaptation with no additional circuitry. Because the gate currents are small, the circuit exhibits a high-pass characteristic with a cutoff frequency less than 1 Hz. The high-frequency cutoff is controlled electronically, as is done in continuous-time filters. We have derived analytical models that completely characterize the amplifier and that are in good agreement with experimental data for a wide range of operating conditions and …
Multiple-Input Translinear Element Networks, Bradley Minch, Paul Hasler, Chris Diorio
Multiple-Input Translinear Element Networks, Bradley Minch, Paul Hasler, Chris Diorio
Bradley Minch
We describe a new class of translinear circuits that accurately embody product-of-power-law relationships in the current signal domain. We call such circuits multiple-input translinear element (MITE) networks. A MITE is a circuit element, which we defined recently that produces an output current that is exponential in a weighted sum of its input voltages. We describe intuitively the basic operation of MITE networks and provide a systematic matrix technique for analyzing the nonlinear relationships implemented by any given circuit. We also show experimental data from three MITE networks that were fabricated in a 1.2-μm double-poly CMOS process.
A Second-Order Section Built From Autozeroing Floating-Gate Amplifiers, Paul Hasler, Theron Stanford, Bradley Minch
A Second-Order Section Built From Autozeroing Floating-Gate Amplifiers, Paul Hasler, Theron Stanford, Bradley Minch
Bradley Minch
We introduce the autozeroing floating-gate (AFGA) secondorder section. We built this second-order filter where the corner frequency and Q are electronically tunable based on a classic filter topology and principles of operational transconductance amplifiers. We built this second order filter using three AFGAs—our floating-gate amplifier that sets its operating point by the interaction of hot-electron injection and electron tunneling.
Low-Cost Stereo Vision On An Fpga, Chris A. Murphy, Daniel Lindquist, Ann Marie Rynning, Thomas Cecil, Sarah Leavitt, Mark L. Chang
Low-Cost Stereo Vision On An Fpga, Chris A. Murphy, Daniel Lindquist, Ann Marie Rynning, Thomas Cecil, Sarah Leavitt, Mark L. Chang
Mark L. Chang
We present a low-cost stereo vision implementation suitable for use in autonomous vehicle applications and designed with agricultural applications in mind. This implementation utilizes the Census transform algorithm to calculate depth maps from a stereo pair of automotive-grade CMOS cameras. The final prototype utilizes commodity hardware, including a Xilinx Spartan-3 FPGA, to process 320times240 pixel images at greater than 150 frames per second and deliver them via a USB 2.0 interface.
Evaluation And Design Optimization Of Piezoresistive Gauge Factor Of Thick-Film Resistors, Sherra E. Kerns, David V. Kerns, C Song, J. L. Davidson, W. P. Kang
Evaluation And Design Optimization Of Piezoresistive Gauge Factor Of Thick-Film Resistors, Sherra E. Kerns, David V. Kerns, C Song, J. L. Davidson, W. P. Kang
Sherra E. Kerns
On the basis of the analysis of all the thick- film design methodologies, the authors designed a test sample on which four different length-over-width ratios of resistors were designed. They found that the length-over-width ratio will substantially affect the gauge factor in some cases, in contrast to prior research. This can be modeled to generate a linear predictive model, The sensors designed on the insulator and the sensors underneath the insulator were also studied in order to simulate the multilayer hybrid technology and study the effects of insulator-resistor-substrate surface interaction. It is demonstrated that design techniques can affect the strain …
Single-Event Charge Enhancement In Soi Devices, David Kerns, Sherra Kerns, L Massengill, M Alles
Single-Event Charge Enhancement In Soi Devices, David Kerns, Sherra Kerns, L Massengill, M Alles
Sherra E. Kerns
Studies are presented of single-particle ion effects in body-tied CMOS/silicon-on-insulator (SOI) devices. It is shown that two mechanisms can contribute to SOI soft-error rates: a direct ion-induced photocurrent and a local lateral bipolar current. The total amount of charge collected is sensitive to the relative locations of the ion strike and the body-to-source tie.
Measurement Of Metal Migration On Thick Film Piezoresistors And Their Termination, David V. Kerns, C Song, J L. Davidson, D L. Kinser
Measurement Of Metal Migration On Thick Film Piezoresistors And Their Termination, David V. Kerns, C Song, J L. Davidson, D L. Kinser
David V. Kerns
Metal migration from the thick-film termination can affect not only the electrical characteristics but also the gauge factor or piezoresistive coefficient of thick-film sensors. Four sets of sensors with different ratios were designed to test the influence of the terminal metal migration effects on the gauge factors and resistivity of thick-film resistors. In all the cases, the shortest resistors have a lower gauge factor and a large deviation ofresistances. The longer resistors will have better electrical parameters. SEM (scanning electron microscope) studies showed this interaction at the interface between the terminal and the resistor. The same distance of terminal diffusion …
Evaluation And Design Optimization Of Piezoresistive Gauge Factor Of Thick-Film Resistors, Sherra E. Kerns, David V. Kerns, C Song, J. L. Davidson, W. P. Kang
Evaluation And Design Optimization Of Piezoresistive Gauge Factor Of Thick-Film Resistors, Sherra E. Kerns, David V. Kerns, C Song, J. L. Davidson, W. P. Kang
David V. Kerns
On the basis of the analysis of all the thick- film design methodologies, the authors designed a test sample on which four different length-over-width ratios of resistors were designed. They found that the length-over-width ratio will substantially affect the gauge factor in some cases, in contrast to prior research. This can be modeled to generate a linear predictive model, The sensors designed on the insulator and the sensors underneath the insulator were also studied in order to simulate the multilayer hybrid technology and study the effects of insulator-resistor-substrate surface interaction. It is demonstrated that design techniques can affect the strain …
Single-Event Charge Enhancement In Soi Devices, David Kerns, Sherra Kerns, L Massengill, M Alles
Single-Event Charge Enhancement In Soi Devices, David Kerns, Sherra Kerns, L Massengill, M Alles
David V. Kerns
Studies are presented of single-particle ion effects in body-tied CMOS/silicon-on-insulator (SOI) devices. It is shown that two mechanisms can contribute to SOI soft-error rates: a direct ion-induced photocurrent and a local lateral bipolar current. The total amount of charge collected is sensitive to the relative locations of the ion strike and the body-to-source tie.
Exoerience With The Analysis Of Small Signal Stability In Longitudinal Power Systems: A Case Study With The Mexican Interconnected System, Arturo Roman Messina
Exoerience With The Analysis Of Small Signal Stability In Longitudinal Power Systems: A Case Study With The Mexican Interconnected System, Arturo Roman Messina
A. R. Messina
In this paper a fundamental study of the small signal stability characteristics of a longitudinal system representing a major equivalent of the Mexican power system is presented. The special characteristics of the Mexican system are emphasized and a number of studies regarding the nature and sources of low frequency oscillations are discussed. These studies reveal the emergence of an undamped swing mode #tvolving the interaction of several machines and their controllers spread out over a large geographical area. The influence of system structure and loading, load effect and the
"Power System Frequency Deviation Measurement Using An Electronic Bridge, Mukhtar Ahmad
"Power System Frequency Deviation Measurement Using An Electronic Bridge, Mukhtar Ahmad
Mukhtar Ahmad
No abstract provided.
A Digital Tachometer For Measurement Of Low Speeds, Mukhtar Ahmad
A Digital Tachometer For Measurement Of Low Speeds, Mukhtar Ahmad
Mukhtar Ahmad
No abstract provided.