Materials with a strong spin Hall effect and Rashba-Edelstein effect have the potential to improve the efficiency of solid-state magnetic memory technologies and other magnetic logic devices. Heavy metals have been identified as having these properties, including the beta crystal phase of tungsten. In this work, we determine the strength...
Continuous Improvement (CI) of academic computing programs is a main requirement of accreditation. Academic computing programs must have a well-documented CI plan in order to be granted accreditation. Based on the existing literature, we developed a comprehensive CI (or 360-CI) model consisting of 8 components: course, curriculum, administration, faculty, research,...
This work demonstrates correlation of microwave signals encoded with 16-bit codes using the parametric interaction of spin waves. Signal processing correlators are devices that compare two signals, such as a reference code and a received code, where the output indicates the similarity between the signals. Correlators are used in communication...
Suspensions of particles in fluids are everywhere in our life, such as paints, pharmacies, food, etc. Suspensions can exhibit properties that common fluids do not possess. For example, the paint needs to flow well when brushing so that it can be smeared on the wall, which is aided by the...
Magnetic particle imaging (MPI) is a biomedical imaging technique which detects the presence of magnetic nanoparticles which have been introduced into the specimen prior to imaging. MPI has shown promise for real-time imaging with spatial resolution comparable to magnetic resonance imaging (MRI). MPI research has focused predominantly on the development...
The research presented herein focuses on electrical assessment of oxide thin films as insulators. The current density-electric field (J-E) characteristics of four insulators of dramatically different electrical quality are assessed in terms of their operative electronic conduction mechanisms. Conduction in the two high-quality insulators is dominated by Ohmic conduction and...
The trend towards higher resolution, faster refresh rate active-matrix liquid-crystal displays (AMLCDs) as well as the emergence of active-matrix organic light-emitting diode (AMOLED) displays is driving the demand for amorphous oxide semiconductor thin-film transistors (AOS TFTs) with higher mobility. A physics-based model for carrier transport in an amorphous semiconductor is...
Geomagnetically Induced Currents (GICs) are quasi-DC signals that are induced in the ground during geomagnetic disturbances (GMDs) and pose a large threat to power grid infrastructure. The power industry currently attempts to mitigate GIC effects by utilizing 1-D ground electrical conductivity based electric field predictions, though conductivity can vary in...
Spintronics is an emerging field of research wherein the electron spin instead of, or along with, the conventional electron charge may be utilized in developing next generation logic devices. One of the most promising aspects of spintronics is that information transfer may be achieved by spin waves in logic devices,...
It has been estimated that data traffic from the different mobile devices that range from smartphones to machine-to-machine (M2M) devices will exceed 15.9 exabyte per month by the year 2018. With this immense data growth, the current wireless communication systems suffer from the scarcity of the radio spectrum and eventually...
Inkjet printing offers a cost effective, highly customizable method for rapid manufacturing of functional devices with minimal material waste. Although this method has been used for a variety of composites, little work has been done in the area of 3D printing magnetic composites. Presented here is a process for inkjet...
In the past few decades, magnetic recording has been used as a dominant solution for massive data storage due to its large capacity, excellent reliability and low cost. Nowadays, exponentially increasing user-generated information is creating a huge demand as well as great challenges for high density data storage solutions. For...
The objective of the work reported herein is to explore the impact of decreasing channel thickness on radio-frequency (RF) sputtered amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) electrical performance through the evaluation of drain current versus gate voltage (I[subscript D] − V[subscript G]) transfer curves. For a fixed set of...
Illuminated contour lines, where line width and color are varied based on an angle of illumination, date back to the mid-nineteenth century, but their effectiveness compared to conventional contour lines has not been fully examined. Currently, illuminated contour lines are not widely used in computer-based cartography because they are not...
The aim of the research undertaken for this thesis was to develop a new high-performance amorphous oxide semiconductor (AOS) for use as a channel layer in a thin-film transistor (TFT). AOS TFTs offer higher electron mobility than the established amorphous silicon based technology. A new channel material comprised of aluminum...
The addition of thin-film alloy magnetic materials to integrated circuit processing enables a number of novel monolithic circuits. Examples include fully integrated magnetic field sensors, signal and power galvanic isolation circuits, and power supplies on chip (PwrSoC). There are several benefits to integrating these traditionally off-chip devices, including improved manufacturability,...
Spintronics is an emerging field of research dealing with devices that can potentially exploit the additional degree of freedom provided by the electron spin along with or instead of the conventional electronic charge. One of the most promising aspects of spintronics is the potential use of magnetostatic spin waves as...
In advanced integrated circuit (IC) processes, the metal fill inserted to meet foundry imposed density requirements degrades the performance of interconnects and passive components which ultimately affects the overall circuit performance. Accounting for this degradation through electromagnetic and equivalent circuit modeling is becoming a critical aspect of IC design. However,...
Ultra-high-speed (>10GS/s), medium-resolution (5~6bit), low-power (<50mW) analog-to-digital converter can find it application in the areas of digital oscilloscopes and next-generation serial link receivers. There are several challenges to enable a successful design, however. First, the time-interleaved architecture is required in order to achieve over 10GS/s sampling rate, with the trade-off...
Bees provide vital ecosystem services for cropping systems as well as natural landscapes. Declines in both both native bee and managed honey bee (Apis mellifera L.) populations has brought attention to the significance of their role as pollinators in managed and native ecosystems. As a result, conservation efforts have been...
A comprehensive and scalable solution for high-performance switched capacitor amplification is presented. Central to this discussion is the concept of ring amplification. A ring amplifier is a small modular amplifier derived from a ring oscillator that naturally embodies all the essential elements of scalability. It can amplify with accurate rail-to-rail...
Indium-gallium-zinc oxide (IGZO) and zinc-tin oxide (ZTO) are investigated for thin-film transistor (TFT) applications. Negative bias illumination stress (NBIS) is employed for electrical stability assessment. Unpassivated IGZO and ZTO TFTs suffer from severe NBIS instabilities. Zinc-tin-silicon oxide is found to be an effective passivation layer for IGZO and ZTO TFTs,...
Short-range wireless communications continually attract interest from both industry and academia, and it is changing our life in every aspect in the last decade. The design of wireless transceivers is the bottleneck for variety applications, due to RF modeling inaccuracy, stringent FCC regulations over the transmitted power spectrum, interference, multi-path...
High speed and high resolution analog-to-digital converter is a key building block for broadband wireless communications, high definition video applications, medical images and so on. By leveraging the down scaling of the latest CMOS technology and the noise shaping properties, delta-sigma (ΔΣ) ADCs are able to achieve wide-band operation and...
With increasing transistor operating frequencies, interconnects and passive devices are becoming performance limiters in integrated circuit (IC) designs. To combat this, the interconnect layers above the active silicon are trending toward low-κ dielectrics and Cu metallization. The use of these new materials has popularized chemical mechanical polishing (CMP) to planarize...
Magnetically programmable surface acoustic wave (MP SAW) devices were designed, fabricated and characterized in this thesis using integrated giant magnetoresistive (GMR) bits with interdigital reflectors. This provides a proof of concept of a novel storage element on radio frequency identification tags. Interdigital transducers (IDTs) on a piezoelectric substrate are used...
A class of inorganic thin-film transistor (TFT) semiconductor materials has emerged involving oxides composed of post-transitional cations with (n-1)d¹⁰ns⁰ (n≥4) electronic configurations. This thesis is devoted to the pursuit of topics involving the development of these materials for TFT applications: Deposition of zinc oxide and zinc tin oxide semiconductor
layers...
This research work focuses on the mechanism of 1/f noise in GaAs
resistors on semi-insulating substrates and 1/f noise due to temperature
fluctuations in heat conduction in resistors, diodes, and bipolar transistors. The
goal of this research is to generate accurate models to explain physical origin of 1/f
noise in...
Enabled by continued device scaling in CMOS technology, more and more functions that were previously realized in separate chips are getting integrated on a single chip nowadays. Integration on silicon has opened the door to new portable wireless applications, and initiated a widespread use of these devices in our common...
Multiple-input multiple-output (MIMO) communication systems have recently been considered as one of the most significant technology breakthroughs for modern wireless communications, due to the higher spectral efficiency and improved link reliability. The sphere decoding algorithm (SDA) has been widely used for maximum likelihood (ML) detection in MIMO systems. It is...
The aim of this dissertation is to develop oxide semiconductors by radio-frequency
sputtering for thin-film transistor (TFT) applications. A variety of oxide semiconductors
are used as the TFT channel layer, including indium gallium oxide (IGO), zinc tin
oxide (ZTO), and indium gallium zinc oxide (IGZO). The variety of materials used...
High performance multi-cell delta-sigma modulators are a preferred choice in applications which require programmability. Multi-cell delta-sigma modulators with M unit cells provide 10log10(M) SQNR improvement for the same thermal noise and bias power due to the uncorrelated quantization noises of the M unit ADCs. This concept is used in this...
This dissertation presents a dual-path 2-0 MASH (Multi-stAge-noise -SHaping) ADC with two verified digital corrections of DAC mismatch error and quantization noise leakage. By using these two techniques, the requirements for the analog circuits are greatly relaxed. The dual-path structure generates two outputs, one only composed of conversion errors, the...
The primary objective of the thesis research is to study novel schemes of on-chip crosstalk suppression employing magnetic films at microwave frequencies. Since extraction of various material properties of the magnetic films is essential for successful application of the proposed method, the research also involves development of a new material...
Orthogonal frequency division multiplexing (OFDM), which has been very attractive for future high rate wireless communications, is very robust to channel multipath fading effect while providing high transmission data rate with high spectral efficiency.
Multiple antennas can be combined with OFDM to increase diversity gain and to improve spectral efficiency...
Surface acoustic wave (SAW) sensors are versatile devices that can be configured to sense a variety of measurands such as temperature and pressure. The potential use of surface acoustic wave devices for magnetic field detection is explored in this study. Compared to current magnetic field sensors, a sensor based on...
Ultra-wideband (UWB) radio is the transmission of data using an extremely wide bandwidth and very low power spectral density. In this thesis, the mereits and challenges of UWB architectures versus conventional narrowband architectures will be compared. Pulsed UWB systems can be implemented with very simple architectures. These advantages make UWB...
Spacecrafts experience radiation in the course of their operation
and all electronic equipment on board these spacecrafts has to
be designed to withstand the effects of this radiation.
This thesis describes the effects of total ionization dose (TID)
and single event transients (SET) in phase-locked loops - an
important circuit...