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Full-Text Articles in Engineering

Spectral-Efficiency Of Multi-Antenna Links In Ad-Hoc Networks With Limited Tx Csi, Siddhartan Govindasamy, Daniel Bliss, David Staelin Dec 2012

Spectral-Efficiency Of Multi-Antenna Links In Ad-Hoc Networks With Limited Tx Csi, Siddhartan Govindasamy, Daniel Bliss, David Staelin

Siddhartan Govindasamy

An asymptotic expression is derived for the mean spectral efficiency of multi-antenna links randomly distributed on a plane in a uniform manner where transmitters (Tx) have Channel-State-Information (CSI) of the channels between themselves and their target receivers while receivers (Rx) have CSI between themselves and all transmitters. The mean per-link spectral efficiency in the network is found to increase if nodes transmit using a subset of their strongest channel modes instead of the link-optimal strategy of water-filling on all channel modes (Farrokhi et al.). For reasonable parameters, this system which requires limited Tx CSI, has approximately double the mean spectral …


Spectral Efficiency In Single-Hop Ad-Hoc Wireless Networks With Interference Using Adaptive Antenna Arrays, Siddhartan Govindasamy, Daniel Bliss, David Staelin Dec 2012

Spectral Efficiency In Single-Hop Ad-Hoc Wireless Networks With Interference Using Adaptive Antenna Arrays, Siddhartan Govindasamy, Daniel Bliss, David Staelin

Siddhartan Govindasamy

Receivers with N antennas in single-hop, ad-hoc wireless networks with nodes randomly distributed on an infinite plane with uniform area density are studied. Transmitting nodes have single antennas and transmit simultaneously in the same frequency band with power P that decays with distance via the commonly-used inverse-polynomial model with path-loss-exponent (PLE) greater than 2. This model applies to shared spectrum systems where multiple links share the same frequency band. In the interference-limited regime, the average spectral efficiency of a representative link E[C] (b/s/Hz/link) is found to grow as log(N) and linearly with PLE, and its variance decays as 1/N. The …


Cdf Of The Spectral-Efficiency Of A Simple Distributed Channel Assignment Algorithm In Spatially Distributed Wireless Networks, Siddhartan Govindasamy, Raghu Rangan, Elena Koukina, Ashley Lloyd Dec 2012

Cdf Of The Spectral-Efficiency Of A Simple Distributed Channel Assignment Algorithm In Spatially Distributed Wireless Networks, Siddhartan Govindasamy, Raghu Rangan, Elena Koukina, Ashley Lloyd

Siddhartan Govindasamy

The Cumulative-Distribution-Function (CDF) of the spectral efficiency of links in spatially distributed networks with orthogonal channels and a simple channel assignment algorithm is presented for constant link-lengths and nearest-neighbor links. Transmitters are randomly distributed on the plane with uniform probability, and receivers are either randomly distributed or at hexagonal lattice sites. This result includes random channel assignments as a special case. The CDF is used to find the spectral efficiency for a given, small outage probability which is used to optimize the number of channels to maximize the spectral efficiency. The optimum number of channels represents the best trade off …


On The Spectral Efficiency Of Links With Multi-Antenna Receivers In Non-Homogenous Wireless Networks, Siddhartan Govindasamy, Daniel Bliss Dec 2012

On The Spectral Efficiency Of Links With Multi-Antenna Receivers In Non-Homogenous Wireless Networks, Siddhartan Govindasamy, Daniel Bliss

Siddhartan Govindasamy

An asymptotic technique is developed to find the Signal-to-Interference-plus-Noise-Ratio (SINR) and spectral efficiency of a link with N receiver antennas in wireless networks with non-homogeneous distributions of nodes. It is found that with appropriate normalization, the SINR and spectral efficiency converge with probability 1 to asymptotic limits as N increases. This technique is applied to networks with power-law node intensities, which includes homogeneous networks as a special case, to find a simple approximation for the spectral efficiency. It is found that for receivers in dense clusters, the SINR grows with N at rates higher than that of homogeneous networks and …


The Performance Of Linear Multiple-Antenna Receivers With Interferes Distributed On A Plane, Siddhartan Govindasamy, Filip Antic, Daniel Bliss, David Staelin Dec 2012

The Performance Of Linear Multiple-Antenna Receivers With Interferes Distributed On A Plane, Siddhartan Govindasamy, Filip Antic, Daniel Bliss, David Staelin

Siddhartan Govindasamy

We find an asymptotic expression for the average signal to interference ratio (SIR) between a transmitter with a single isotropic antenna and a multi-antenna linear receiver in the presence of interferers with single isotropic transmit antennas distributed uniformly on an infinite plane. The channels are modeled as complex Gaussian random variables with average received power dependent on the distance separating nodes. We find that in large networks, the average SIR for a representative link depends primarily on the ratio of the number of receive antenna elements to the area density of interferers. Furthermore for our network model, the SIR grows …


Minimizing Hidden-Node Network Interference By Optimizing Siso And Mimo Spectral Efficiency, Daniel Bliss, Siddhartan Govindasamy Dec 2012

Minimizing Hidden-Node Network Interference By Optimizing Siso And Mimo Spectral Efficiency, Daniel Bliss, Siddhartan Govindasamy

Siddhartan Govindasamy

In this paper, the optimal spectral efficiency (data rate divided by the message bandwidth) that minimizes the probability of causing disruptive interference for ad hoc wireless networks or cognitive radios is investigated. Two basic problem constraints are considered: a given message size, or fixed data rate. Implicitly, the trade being optimized is between longer transmit duration and wider bandwidth versus higher transmit power. Both single-input single-output (SISO) and multiple-input multiple-output (MIMO) links are considered. Here, a link optimizes its spectral efficiency to be a “good neighbor.” The probability of interference is characterized by the probability that the signal power received …


Linear Mmse Receivers For Random Cdma In Wireless Networks With Equal Transmit Powers, Siddhartan Govindasamy, David Staelin Dec 2012

Linear Mmse Receivers For Random Cdma In Wireless Networks With Equal Transmit Powers, Siddhartan Govindasamy, David Staelin

Siddhartan Govindasamy

The performance of single-hop links in ad-hoc wireless systems using direct-sequence (DS) code-division-multiple-access (CDMA) with random signature sequences and linear minimum-mean-square-error (MMSE) receivers is investigated. Expressions for the average signal-to-interference-plus-noise-ratio (SINR) and spectral efficiency (b s-1 Hz-1 link-1) were derived for a representative link in the presence of interferers distributed randomly on a plane with uniform area density p interferers m-2. Nodes transmit with equal power P, which decays with distance r as r-alpha. An expression for the optimum spreading factor given system parameters is also provided. It is found that for …


Asymptotic Spectral Efficiency Of Multiantenna Links In Wireless Networks With Limited Tx Csi, Siddhartan Govindasamy, Daniel Bliss, David Staelin Dec 2012

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 …


Spectral Efficiency Of Wireless Networks With Multi-Antenna Base Stations And Spatially Distributed Nodes, Siddhartan Govindasamy, Daniel Bliss, David Staelin Dec 2012

Spectral Efficiency Of Wireless Networks With Multi-Antenna Base Stations And Spatially Distributed Nodes, Siddhartan Govindasamy, Daniel Bliss, David Staelin

Siddhartan Govindasamy

We analyze networks with wireless nodes distributed randomly in space, transmitting simultaneously in the same channel to their nearest base-stations using a simple power control algorithm. Base-stations are on a hexagonal grid and have N optimally-phased antennas. We derive the asymptotic mean upstream spectral efficiency(validated by simulation) as a function of N, wireless-node density, base-station separation, and path-loss-exponent which controls signal attenuation with distance. These results indicate that mean per-link spectralefficiency is constant if the number of receive antennas or density of base-stations is increased linearly withwireless node density. They also improve our understanding of systems like city-wide wireless Internet …


Vacuum Microelectronic Integrated Differential Amplifier, S. Hsu, W. Kang, J. Davidson, J. Huang, David Kerns, Jr. Aug 2012

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 …


A Physical Model For The Kink Effect In Inalas/Ingaas Hemt’S, Mark Somerville, Alexander Ernst, Jesus Del Alamo Jul 2012

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.


Degradation Uniformity Of Rf-Power Gaas Phemts Under Electrical Stress, Anita Villanueva, Jesus Del Alamo, Takayuki Hisaka, Kazuo Hayashi, Mark Somerville Jul 2012

Degradation Uniformity Of Rf-Power Gaas Phemts Under Electrical Stress, Anita Villanueva, Jesus Del Alamo, Takayuki Hisaka, Kazuo Hayashi, Mark Somerville

Mark Somerville

We have studied the electrical degradation of RF-power PHEMTs by means of in situ 2-D light-emission measurements. Electroluminescence originates in the recombination of holes that have been generated by impact ionization. The local light intensity, thus, maps the electric-field distribution at the drain side of the device. This allows us to probe the uniformity of electrical degradation due to electric-field-driven mechanisms. We find that electrical degradation proceeds in a highly nonuniform manner across the width of the device. In an initial phase, degradation takes place preferentially toward the center of the gate finger. In advanced stages of degradation, the edges …


Determining Dominant Breakdown Mechanisms In Inp Hemts, Mark Somerville, Chris Putnam, Jesus Del Alamo Jul 2012

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.


Film Thickness Constraints For Manufacturable Strained Silicon Cmos, J. Fiorenza, G. Braithwaite, C. Leitz, M. Currie, J. Yap, F. Singaporewala, V. Yang, T. Langdo, J. Carlin, Mark Somerville, A. Lochtefeld, H. Badawi, M. Bulsara Jul 2012

Film Thickness Constraints For Manufacturable Strained Silicon Cmos, J. Fiorenza, G. Braithwaite, C. Leitz, M. Currie, J. Yap, F. Singaporewala, V. Yang, T. Langdo, J. Carlin, Mark Somerville, A. Lochtefeld, H. Badawi, M. Bulsara

Mark Somerville

This paper studies the effect of the strained silicon thickness on the characteristics of strained silicon MOSFETs on SiGe virtual substrates. NMOSFETs were fabricated on strained silicon substrates with various strained silicon thicknesses, both above and below the strained silicon critical thickness. The low field electron mobility and subthreshold characteristics of the devices were measured. Low field electron mobility is increased by about 1.8 times on all wafers and is not significantly degraded on any of the samples, even for a strained silicon thickness far greater than the critical thickness. From the subthreshold characteristics, however, it is shown that the …


Physical Mechanisms Limiting The Manufacturing Uniformity Of Millimeter-Wave Power Inp Hemt's, Sergei Krupenin, Roxann Blanchard, Mark Somerville, Jesus Del Alamo, K. Duh, Pane Chao Jul 2012

Physical Mechanisms Limiting The Manufacturing Uniformity Of Millimeter-Wave Power Inp Hemt's, Sergei Krupenin, Roxann Blanchard, Mark Somerville, Jesus Del Alamo, K. Duh, Pane Chao

Mark Somerville

We have developed a methodology to diagnose the physical mechanisms limiting the manufacturing uniformity of millimeter-wave power InAlAs/InGaAs HEMT's on InP. A statistical analysis was carried out on dc figures of merit obtained from a large number of actual devices on an experimental wafer. Correlation studies and principal component analysis of the results indicated that variations in Si delta-doping concentration introduced during molecular-beam epitaxy accounted for more than half of the manufacturing variance. Variations in the gate-source distance that is determined by the electron-beam alignment in the gate formation process were found to be the second leading source of manufacturing …


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 Jul 2012

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 …


Fully Depleted N-Mosfets On Supercritical Thickness Strained Soi, Isaac Lauer, T. Langdo, Z.-Y. Cheng, J. Fiorenza, G. Braithwaite, M. Currie, C. Leitz, A. Lochtefeld, H. Badawi, M. Bulsara, Mark Somerville, Dimitri Antoniadis Jul 2012

Fully Depleted N-Mosfets On Supercritical Thickness Strained Soi, Isaac Lauer, T. Langdo, Z.-Y. Cheng, J. Fiorenza, G. Braithwaite, M. Currie, C. Leitz, A. Lochtefeld, H. Badawi, M. Bulsara, Mark Somerville, Dimitri Antoniadis

Mark Somerville

Strained silicon-on-insulator (SSOI) is a new material system that combines the carrier transport advantages of strained Si with the reduced parasitic capacitance and improved MOSFET scalability of thin-film SOI. We demonstrate fabrication of highly uniform SiGe-free SSOI wafers with 20% Ge equivalent strain and report fully depleted n-MOSFET results. We show that enhanced mobility is maintained in strained Si films transferred directly to SiO2 from relaxed Si0.8Ge0.2 virtual substrates, even after a generous MOSFET fabrication thermal budget. Further, we find the usable strained-Si thickness of SSOI significantly exceeds the critical thickness of strained Si/SiGe without deleterious leakage current effects typically …


On An Orthogonal Space-Time-Polarization Block Code, Beata Wysocki, Tadeusz Wysocki, Sarah Adams Jul 2012

On An Orthogonal Space-Time-Polarization Block Code, Beata Wysocki, Tadeusz Wysocki, Sarah Adams

Sarah Spence Adams

Over the past several years, diversity methods such as space, time, and polarization diversity have been successfully implemented in wireless communications systems. Orthogonal space-time block codes efficiently combine space and time diversity, and they have been studied in detail. Polarization diversity has also been studied, however it is usually considered in a simple concatenation with other coding methods. In this paper, an efficient method for incorporating polarization diversity with space and time diversity is studied. The simple yet highly efficient technique is based on extending orthogonal space-time block codes into the quaternion domain and utilizing a description of the dual-polarized …


Novel Constructions Of Improved Square Complex Orthogonal Designs For Eight Transmit Antennas, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins, Sarah Adams Jul 2012

Novel Constructions Of Improved Square Complex Orthogonal Designs For Eight Transmit Antennas, Le Chung Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins, Sarah Adams

Sarah Spence Adams

Constructions of square, maximum rate complex orthogonal space-time block codes (CO STBCs) are well known, however codes constructed via the known methods include numerous zeros, which impede their practical implementation. By modifying the Williamson and Wallis-Whiteman arrays to apply to complex matrices, we propose two methods of construction of square, order-4n CO STBCs from square, order-n codes which satisfy certain properties. Applying the proposed methods, we construct square, maximum rate, order-8 CO STBCs with no zeros, such that the transmitted symbols are equally dispersed through transmit antennas. Those codes, referred to as the improved square CO STBCs, have the advantages …


An Extension Of The Channel-Assignment Problem: L(2, 1)-Labelings Of Generalized Petersen Graphs, Sarah Adams, Jonathan Cass, Denise Troxell Jul 2012

An Extension Of The Channel-Assignment Problem: L(2, 1)-Labelings Of Generalized Petersen Graphs, Sarah Adams, Jonathan Cass, Denise Troxell

Sarah Spence Adams

The channel-assignment problem involves assigning frequencies represented by nonnegative integers to radio transmitters such that transmitters in close proximity receive frequencies that are sufficiently far apart to avoid interference. In one of its variations, the problem is commonly quantified as follows: transmitters separated bythe smallest unit distance must be assigned frequencies that are at least two apart and transmitters separated by twice the smallest unit distance must be assigned frequencies that are at least one apart. Naturally, thischannel-assignment problem can be modeled with vertex labelings of graphs. An L(2, 1)-labeling of a graph G is a function f from the …


Quaternion Orthogonal Designs From Complex Companion Designs, Sarah Adams, Jennifer Seberry, Nathaniel Karst, Jonathan Pollack, Tadeusz Wysocki Jul 2012

Quaternion Orthogonal Designs From Complex Companion Designs, Sarah Adams, Jennifer Seberry, Nathaniel Karst, Jonathan Pollack, Tadeusz Wysocki

Sarah Spence Adams

The success of applying generalized complex orthogonal designs as space–time block codes recently motivated the definition of quaternion orthogonal designs as potential building blocks for space–time-polarization block codes. This paper offers techniques for constructing quaternion orthogonal designs via combinations of specially chosen complex orthogonal designs. One technique is used to build quaternion orthogonal designs on complex variables for any even number of columns. A second related technique is applied to maximum rate complex orthogonal designs to generate an infinite family of quaternion orthogonal designs on complex variables such that the resulting designs have no zero entries. This second technique is …


The Final Case Of The Decoding Delay Problem For Maximum Rate Complex Orthogonal Designs, Sarah Adams, Nathaniel Karst, Mathav Murugan Jul 2012

The Final Case Of The Decoding Delay Problem For Maximum Rate Complex Orthogonal Designs, Sarah Adams, Nathaniel Karst, Mathav Murugan

Sarah Spence Adams

Complex orthogonal space-time block codes (COSTBCs) based on generalized complex orthogonal designs (CODs) have been successfully implemented in wireless systems with multiple transmit antennas and single or multiple receive antennas. It has been shown that for a maximum rate COD with 2m-1 or 2m columns, a lower bound on decoding delay is (m-1 2m) and this delay is achievable when the number of columns is congruent to 0, 1 , or 3 modulo 4. In this paper, the final case is addressed, and it is shown that when the number of columns is congruent to 2 modulo 4, the lower …


An Autozeroing Floating-Gate Amplifier, Paul Hasler, Bradley Minch, Chris Diorio Jul 2012

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 Jul 2012

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.


Synthesis Of Static And Dynamic Multiple-Input Translinear Element Networks, Bradley Minch Jul 2012

Synthesis Of Static And Dynamic Multiple-Input Translinear Element Networks, Bradley Minch

Bradley Minch

In this paper, we discuss the process of synthesizing static and dynamic multiple-input translinear element (MITE) networks systematically from high-level descriptions given in the time domain, in terms of static polynomial constraints and algebraic differential equations. We provide several examples, illustrating the process for both static and dynamic system constraints. Although our examples will all involve MITE networks, the early steps of the synthesis process are equally applicable to the synthesis of static and dynamic translinear-loop circuits.


Integration Of Chemical Sensing And Electrowetting Actuation On Chemoreceptive Neuron Mos (Cνmos) Transistors, Nick Shen, Zengtao Liu, Blake Jacquot, Bradley Minch, Edwin Kan Jul 2012

Integration Of Chemical Sensing And Electrowetting Actuation On Chemoreceptive Neuron Mos (Cνmos) Transistors, Nick Shen, Zengtao Liu, Blake Jacquot, Bradley Minch, Edwin Kan

Bradley Minch

An integration of chemical sensors and electrowetting actuators based on the chemoreceptive neuron MOS (CνMOS) transistors has brought forth a novel system-on-chip approach to the microfluidic system. The extended floating-gate structure of the CνMOS transistors enables monolithic sensing and actuating schemes. The sensors with generic chemical receptive areas have been characterized with various fluids, and have demonstrated a high sensitivity from the current differentiation and a large dynamic range from threshold-voltage shifts in sensing polar and electrolytic liquids. The actuators have illustrated valve functions based on contact-angle modification by nonvolatile charge injection into the channel wall. Electrochemical models for sensing …


A Second-Order Section Built From Autozeroing Floating-Gate Amplifiers, Paul Hasler, Theron Stanford, Bradley Minch Jul 2012

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.


Hysteretic Threshold Logic And Quasi-Delay Insensitive Asynchronous Design, Mark Neidengard, Bradley Minch Jul 2012

Hysteretic Threshold Logic And Quasi-Delay Insensitive Asynchronous Design, Mark Neidengard, Bradley Minch

Bradley Minch

We introduce the class of hysteretic linear-threshold (HLT) logic functions as a novel extension of linear threshold logic, and prove their general applicability for constructing state-holding Boolean functions. We then demonstrate a fusion of HLT logic with the quasi-delay insensitive style of asynchronous circuit design, complete with logical design examples. Future research directions are also identified.


A Physical Compact Model Of Dg Mosfet For Mixed-Signal Circuit Applications - Part I: Model Description, Gen Pei, Weiping Ni, Abhishek Kammula, Bradley Minch, Edwin Kan Jul 2012

A Physical Compact Model Of Dg Mosfet For Mixed-Signal Circuit Applications - Part I: Model Description, Gen Pei, Weiping Ni, Abhishek Kammula, Bradley Minch, Edwin Kan

Bradley Minch

To use double-gate (DG) MOSFET for mixed-signal circuit applications, especially for circuits in which the two gates are independently driven, such as in the case of dynamic-threshold and fixed-potential-plane operations, physical compact models that are valid for all modes of operations are necessary for accurate design and analysis. Employing physically rigorous current-voltage (I-V) relationship in subthreshold and above-threshold regions as asymptotic cases, we have constructed a model that joins the two operating regions by using carrier-screening functions. We have included consistently source/drain series resistance, low drain-field mobility, and small-geometry effects of drain-induced barrier lowering (DIBL), MOS interface mobility, velocity saturation …


Charge-Based Chemical Sensors: A Neuromorphic Approach With Chemoreceptive Neuron Mos (Cvmos) Transistors, Nick Shen, Zengtao Liu, Chungho Lee, Bradley Minch, Edwin Kan Jul 2012

Charge-Based Chemical Sensors: A Neuromorphic Approach With Chemoreceptive Neuron Mos (Cvmos) Transistors, Nick Shen, Zengtao Liu, Chungho Lee, Bradley Minch, Edwin Kan

Bradley Minch

A novel chemoreceptive neuron MOS (CνMOS) transistor with an extended floating-gate structure has been designed with several individual features that significantly facilitate system integration of chemical sensing. We have fabricated CνMOS transistors with generic molecular receptive areas and have characterized them with various fluids. We use an insulating polymer layer to provide physical and electrical isolation for sample fluid delivery. Experimental results from these devices have demonstrated both high sensitivity via current differentiation and large dynamic range from threshold voltage shifts in sensing both polar and electrolytic liquids. We have established electrochemical models for both steady-state and transient analyses. Our …