For today’s ubiquitous portable devices, innovative integrated circuits with high performance
yet very low power are necessary. As these devices are used to communicate and sense real world signals in the environment, analog-to-digital converters (ADC) and systems are the key interface circuits needed to digitize the sensed information and they...
The role of A-site non-stoichiometry was investigated in lead-free piezoelectric ceramics based on compositions in the 1-x(Bi₀.₅Na₀.₅TiO₃)-xBaTiO₃ system near the morphotropic phase boundary where x = 0.055, 0.06 and 0.07. The samples were prepared by a conventional solid state mixed oxide route with the A- site stoichiometry modified to incorporate...
Low-distortion architecture is widely used in wideband discrete-time switched-capacitor delta-sigma ADC design. However, it suffers from the power-hungry active adder and critical timing for quantization and dynamic element matching (DEM). To solve this problem, this dissertation presents a delta-sigma modulator architecture with shifted loop delays. In this project, shifted loop...
New amplifier architectures are presented using non-traditional methods of biasing. Time-based dynamic biasing and signal-based dynamic biasing are discussed in the context of new architectures. This includes a new form of ring amplification with a dynamic deadzone, allowing for a structure whose coarse path does not consume static power.
A new technique is developed to recover elemental tellurium (Te) from cadmium telluride (CdTe) which is abundantly available in photovoltaic semiconductor waste. The method is based on microchannel fluid flow with the use of a supported liquid membrane (SLM) between the donor (feed) and acceptor (strip) channels. A predictive theoretical...
The design of a preamplifier for use with a piezoelectric transducer is generally approached from the point of view that an extremely high input impedance is required to obtain low frequency response. However, piezoelectric transducers are essentially charge generators and this fact may be utilized in designing preamplifiers to be...
The release of the IEEE802.15.6 standard has led to increased interest in low-power technologies for wireless body-area-networks (WBANs). The power dissipation, supply voltage, and die area are some of the most important criteria for successful WBAN implementations. Digital-intensive RX architectures can potentially result in sub-1V operation with significant reductions in...
This thesis describes the adder to be used with the Galaxy computer, which is to be constructed at Oregon State University.
The need for faster, more reliable adders is discussed
along with previous adder designs related to the
Galaxy Fast Carry Adder.
Both the logical design and circuit design of...
Conventional bi-polar transistors are inherently low input
impedance devices. Transistor amplifiers have been designed
which will present high input impedance, but the frequency response
is limited to low frequencies, hundreds of kilocycles.
This thesis investigates both field effect transistors and
positive feedback as applied to high input impedance wide band...
Wideband tunnel-diode amplifiers using common-base
transistor stages for isolation were investigated for
stability criteria, frequency response, and the effects
of temperature and voltage supply fluctuations. For the
first time the full frequency spectrum of a tunnel-diode,
from d-c to the gigahertz (GHz) range, was able to be
utilized in an...