Variations in ionospheric plasma density can cause large amplitude and phase changes in the radio waves passing through this region. Ionospheric weather can have detrimental effects on several communication systems, including radars, navigation systems such as the Global Positioning Sytem (GPS), and high-frequency communications. As a result, creating models of the ionospheric density is of paramount interest to scientists working in the field of satellite communication. Numerous empirical and theoretical models have been developed to study the upper atmosphere climatology and weather. Multiple measurements of plasma density over a region are of marked importance while creating these models. The lack of spatially distributed observations in the upper atmosphere is currently a major limitation in space weather research. A constellation of CubeSat platforms would be ideal to take such distributed measurements. The use of miniaturized instruments that can be accommodated on small satellites, such as CubeSats, would be key to acheiving these science goals for space weather. The accepted instrumentation techniques for measuring the electron density are the Langmuir probes and the Plasma Impedance Probe (PIP). While Langmuir probes are able to provide higher resolution measurements of relative electron density, the Plasma Impedance Probes provide absolute electron density measurements irrespective of spacecraft charging. The central goal of this dissertation is to develop an integrated architecture for the PIP that will enable space weather research from CubeSat platforms. The proposed PIP chip integrates all of the major analog and mixed-signal components needed to perform swept-frequency impedance measurements. The design's primary innovation is the integration of matched Analog-to-Digital Converters (ADC) on a single chip for sampling the probes current and voltage signals. A Fast Fourier Transform (FFT) is performed by an off-chip Field-Programmable Gate Array (FPGA) to compute the probes impedance. This provides a robust solution for determining the plasma impedance accurately. The major analog errors and parametric variations affecting the PIP instrument and its effect on the accuracy and precision of the impedance measurement are also studied. The system clock is optimized in order to have a high performance ADC. In this research, an alternative clock generation scheme using C-elements is described to reduce the timing jitter and reference spurs in phase locked loops. While the jitter performance and reference spur reduction is comparable with prior state-of-the-art work, the proposed Phase Locked Loop (PLL) consumes less power with smaller area than previous designs.

1. There is a crisis in economics. The discipline evolved in nineteenth century Europe and is difficult to adapt to modern conditions, even in the West, and particularly in alien cultures. Application of conventional economic analysis to economic activity in a culture as alien as traditional China highlights the biases in assumptions of the paradigm. 2. The concepts, models and vocabulary evolved over one hundred years ago predate important developments in the natural sciences. It is now necessary for economists to concede no goods can ever be 'produced', and they are not 'consumed' either. In clear terms matter is transformed, but is not created or destroyed (First Law of Thermodynamics). 3. When people transform matter, in lay language we say energy is 'used'. In a simple cottage industry, 'raw material' is transformed into a commodity in front of our eyes by the use of human energy and the release of energy from a 'fuel'. In modem complex economic activity, it is difficult or impossible to keep track of the processes from raw matter to transformed 'product' although the principle is the same. 4. The Second Law of Thermodynamics states that in any transformation, energy is not created or destroyed, but becomes 'less available'. In short, entropy increases. This appears to work well for pure physics and chemistry, but its application to analysis of economic activity has only been notional. 5. There is a reason why economists borrowing terms from hard science experience difficulty. It is because physicists and chemists have addressed specific laboratory and engineering problems, but not the broader economic issues. The hypothesis gradually evolved in this research program that not only economic concepts and terms needed reworking, but those in physics as well. The definitions of energy as 'ability to do works and of entropy as 'unavailable energy' jar the logic of our commonsense. 6. The notion of 'available energy' was traced back to the phenomenon in physical chemistry known as exothermicity, or the release of energy during a chemical reaction. It was reasoned that while scientists had focussed on this phenomenon and measured it carefully they saw no need to ask where the energy came from, or to measure its transformation. From the perspective of analysing economic activity, the question was important. 7. It was hypothesised that the energy released from a fuel as electromagnetic radiation (mainly heat) was the residual of the set of coulombic forces within atoms that maintain the structure of shells of electrons around the protons. This idea in turn came from the presumption that molecular bonding is a residual of vectors of the set of coulombic forces within atoms, and the likelihood that in an exothermic reaction, after the reactants are said (by scientists) to 'seek equilibrium', product molecules have a portion of the coulombic forces 'left over' and not required to maintain their structures. An estimate was made of the coulombic forces extant in various fuels, and compared with the known data for their release of energy. 8. The idea was developed in detail. The concept we call in economics, 'production', and should call 'transformation' can only occur when forces locked within atoms are released as electromagnetic forces. (Gravitational forces exist because matter has been put 'there' by electromagnetic radiation). When 100 grams of dry grass fuel is burnt, about 2 megajoules of electromagnetic radiation are released. It was estimated that the coulombic forces between each electron and proton in that amount dry grass total 150 gigajoules (or giganewtons, since the reference is to forces). 9. Within the boundary of a simple economic activity, the ratio of aggregated coulombic forces locked up within atoms to the electromagnetic forces radiated out was estimated at the beginning of the activity, and then after a duration. The ratio of forces always tends towards 'evening out'. This measurement captures the entropy phenomenon which has been said by Georgescu-Roegen to be the basis of all economic activity. 10. At the roots of the economic paradigm founded by Adam Smith is the premise that the material world, as a set of substances, is a stage on which economic actors 'add value', bid prices up and down, and by their rational perception manage their livelihoods and surroundings well. From the findings of this research program it is contended that the surroundings of economic actors can be classed into two categories: locked up (coulombic) electromagnetic forces, and radiated electromagnetic forces. The former has a tendency to convert to the latter. All action, including all economic activity, and all life can be traced to a point in space and time where this conversion is (naturally) occurring. The phenomenon is analogous to a slope where water cascades, and gravitational potential energy converts to other (either useless or useful) forms of energy. To appreciate the nature of this phenomena, and to attempt to fathom its dimensions, sets our perceptions of ourselves as economic actors in a quite different and very humbling context.

It is relatively straightforward to establish equilibrium inmagnetically confined plasmas, but the plasma is frequentlysucceptible to a variety of instabilities that are driven bythe free energy in the magnetic field or in the pressuregradient. These unstable modes exhibit effects that affect theparticle, momentum and heat confinement properties of theconfiguration. Studies of the dynamics of several of the mostimportant modes are the subject of this thesis. The studies arecarried out on plasmas in the reversed field pinch (RFP)configuration. One phenomenon commonly observed in RFPs is mode walllocking. The localized nature of these phase- and wall lockedstructures results in localized power loads on the wall whichare detrimental for confinement. A detailed study of the walllocked mode phenomenon is performed based on magneticmeasurements from three RFP devices. The two possiblemechanisms for wall locking are investigated. Locking as aresult of tearing modes interacting with a static field errorand locking due to the presence of a non-ideal boundary. Thecharacteristics of the wall locked mode are qualitativelysimilar in a device with a conducting shell system (TPE-RX)compared to a device with a resistive shell (Extrap T2). Atheoretical model is used for evaluating the threshold valuesfor wall locking due to eddy currents in the vacuum vessel inthese devices. A good correlation with experiment is observedfor the conducting shell device. The possibility of succesfully sustaining discharges in aresistive shell RFP is introduced in the recently rebuiltdevice Extrap T2R. Fast spontaneous mode rotation is observed,resulting in low magnetic fluctuations, low loop voltage andimproved confinement. Wall locking is rarely observed. The lowtearingmode amplitudes allow for the theoretically predictedinternal nonresonant on-axis resistive wall modes to beobserved. These modes have not previously been distinguisheddue to the formation of wall locked modes. The internal andexternal nonresonant resistive wall modes grow on the timescale of the shell penetration time. These growth rates dependon the RFP equilibrium. The internal nonresonant resistive wallmodes dominate in Extrap T2R, especially for shallow reverseddischarges. The external nonresonant modes grow solely in deepreversal discharges. <b>Keywords</b>Nuclear fusion, reversed field pinch, resistiveinstabilities, wall locked modes, tearing modes, resistiveshell modes, field errors, EXTRAP-T2, EXTRAP-T2R, TPE-RX

Recent advances in voltage-controlled oscillator (VCO) design and the trend of CMOS processing indicate that the oscillator control is quickly becoming one of the forefront problems in high-frequency and low-phase-noise phase-locked loop (PLL) design. This control centric study explores the limitations and challenges in high-performance analog charge-pump PLLs when they are extended to multiple gigahertz applications. Several problems with performance enhancement and precise oscillator control using analog circuits in low-voltage submicron CMOS processes, coupled with the fact that analog (or semi-digital) oscillators having various advantages over their digitally controlled counterparts, prompted the proposal of the digitally-controlled phase-locked loop. This research, then, investigates a class of otherwise analog PLLs that use a digital control path for driving a current-controlled oscillator. For this purpose, a novel method for control digitization is described where trains of pulses code the phase/frequency comparison information rather than the duration of the pulses: Pulse-Stream Coded Phase-Locked Loop (psc-PLL). This work addresses issues significant to the design of future PLLs through a comparative study of the proposed digital control path topology and improved cutting-edge charge-pump PLLs.

The study for surfaced-immobilized nucleic acid probes in nanometer region in response to hybridization and to discrimination ofdifferent target nuclei acids. The hairpin locked nucleic acid (LNA-HP) isselected to be the probe molecule, and target molecules include perfect complementary (PC) and single mismatch (1MM). The self-assembledLNA-HP molecular nanospot is successfully prepared by liquid phaseAFM (Atomic Force Microscope)-based nanolithography technique, then in situ hybridization is carried out by using different targets (PC/1MM).To obtain the information of structure change, we use AFM to analyze therelative heights in the process of hybridization. The experimental results point out that (1) the structure changes of surface probe molecules maycorrelate with the AFM signal when target sequence hybridizes to the probe, (2) miniaturization of the size of the nucleic acid probe may promote hybridization efficiency and enhance the discrimination between PC and 1MM. Studies on whether the different chemical impetus in solution can affect conformation of the human telomeric DNA of sequence is conducted. A human talomeric DNA composed of ( 5¡¦-TTAGGG-3¡¦:5¡¦-CCCTAA-3¡¦ ) repeats, with a 100-200 nt ( T2AG3 ) repetitive unit overhang at 3¡¦ ends is chosen. This extended single-stranded sequence is called G-rich DNA, which forms the special G-quadruplex structure in solution containing sodium ions or potassium ions. The single-stranded sequence composed of ( C3TA2 ) repetitive units called C-rich DNA displays the i-motif folded structure in the low pH environment. These biomimetic DNA¡¦s are thiol-modified to self-assemble on gold surfaces. Separate measurements with AFM (the molecular thickness and rootmean- square roughness of the self-assembly monolayer of DNA ) and CD( circular dichroism ) ( structure characterization ) confirm the conformational changes of G-rich and C-rich DNA¡¦s on gold surface are indeed dependent of the presence of cations and protons.

As demand for higher bandwidth I/O grows, the front end design of serial link becomes significant to overcome stringent timing requirements on noisy and bandwidthlimited channels. As a clock reconstructing module in a receiver, the recovered clock quality of Clock and Data Recovery is the main issue of the receiver performance. However, from unknown incoming jitter, it is difficult to optimize loop dynamics to minimize steady-state and dynamic jitter. In this thesis a 10 Gb/s adaptive loop bandwidth clock and data recovery circuit with on-chip loop filter is presented. The proposed system optimizes the loop bandwidth adaptively to minimize jitter so that it leads to an improved jitter tolerance performance. This architecture tunes the loop bandwidth by a factor of eight based on the phase information of incoming data. The resulting architecture performs as good as a maximum fixed loop bandwidth CDR while tracking high speed input jitter and as good as a minimum fixed bandwidth CDR while suppressing wide bandwidth steady-state jitter. By employing a mixed mode predictor, high updating rate loop bandwidth adaptation is achieved with low power consumption. Another relevant feature is that it integrates a typically large off-chip filter using a capacitance multiplication technique that employs dual charge pumps. The functionality of the proposed architecture has been verified through schematic and behavioral model simulations. In the simulation, the performance of jitter tolerance is confirmed that the proposed solution provides improved results and robustness to the variation of jitter profile. Its applicability to industrial standards is also verified by the jitter tolerance passing SONET OC-192 successfully.

In this thesis, we present a new continuously variable high frequency standing wave oscillator and demonstrate its use in generating the phase locked clock signal of a digital IC. The ring based standing wave resonant oscillator is implemented with a plurality of wires connected in a mobius configuration, with a cross coupled inverter pair connected across the wires. The oscillation frequency can be modulated by coarse and fine tuning. Coarse modification is achieved by altering the number of wires in the ring that participate in the oscillation, by driving a digital word to a set of passgates which are connected to each wire in the ring. Fine tuning of the oscillation frequency is achieved by varying the body bias voltage of both the PMOS transistors in the cross coupled inverter pair which sustains the oscillations in the resonant ring. We validated our PLL design in a 90nm process technology. 3D parasitic RLCs for our oscillator ring were extracted with skin effect accounted for. Our PLL provides a frequency locking range from 6 GHz to 9 GHz, with a center frequency of 7.5 GHz. The oscillator alone consumes about 25 mW of power, and the complete PLL consumes a power of 28.5 mW. The observed jitter of the PLL is 2.56 percent. These numbers are significant improvements over the prior art in standing wave based PLLs.

High-speed serial data links are quickly gaining in popularity and replacing the conventional parallel data links in recent years when the data rate of communication exceeds one gigabits per second. Compared with parallel data links, serial data links are able to achieve higher data rate and longer transfer distance. This dissertation is focused on the design of CMOS integrated phase-locked loops (PLLs) and relevant building blocks used in multi-gigabits serial data link transceivers. Firstly, binary phase-locked loops (BPLLs, i.e., PLLs based on binary phase detectors) are modeled and analyzed. The steady-state behavior of BPLLs is derived with combined discrete-time and continuous-time analysis. The jitter performance characteristics of BPLLs are analyzed. Secondly, a 10 Gbps clock and data recovery (CDR) chip for SONET OC- 192, the mainstream standard for optical serial data links, is presented. The CDR is based on a novel referenceless dual-loop half-rate architecture. It includes a binary phase-locked loop based on a quad-level phase detector and a linear frequency-locked loop based on a linear frequency detector. The proposed architecture enables the CDR to achieve large locking range and small jitter generation at the same time. The prototype is implemented in 0.18 μm CMOS technology and consumes 250 mW under 1.8 V supply. The jitter generation is 0.5 ps-rms and 4.8 ps-pp. The jitter peaking and jitter tolerance performance exceeds the specifications defined by SONET OC-192 standard. Thirdly, a fully-differential divide-by-eight injection-locked frequency divider with low power dissipation is presented. The frequency divider consists of a four-stage ring of CML (current mode logic) latches. It has a maximum operating frequency of 18 GHz. The ratio of locking range over center frequency is up to 50%. The prototype chip is implemented in 0.18 μm CMOS technology and consumes 3.6 mW under 1.8 V supply. Lastly, the design and optimization techniques of fully differential charge pumps are discussed. Techniques are proposed to minimize the nonidealities associated with a fully differential charge pump, including differential mismatch, output current variation, low-speed glitches and high-speed glitches. The performance improvement brought by the techniques is verified with simulations of schematics designed in 0.35 μm CMOS technology.

In this dissertation, the development of the first 60 GHz-standard compatible fully integrated 4-channel phase-locked loop (PLL) frequency synthesizer has been presented. The frequency synthesizer features third-order single loop architecture with completely integrated passive loop filter that does not require any additional external passive component. Two possible realizations of fully integrated clock and data recovery (CDR) circuits suitable for 60 GHz-standard compliant base band signal processing have been presented for the first time as well. The two CDRs have been optimized for either high data rate (3.456 Gb/s) or very low power consumption (5 mW) and they both work with a single 1 V supply. The frequency synthesizer is intended to generate a variable LO frequency in a fixed-IF heterodyne transceiver architecture. In such configuration the channel selection is implemented by changing the LO frequency by the required frequency step. This method avoids quadrature 50 GHz up/down-conversion thereby lowering the LO mixer design complexity and simplifying the LO distribution network. The measurement results show the PLL locking correctly on each of the four channels while consuming 60 mW from a 1 V power supply. The worst case phase noise is measured to be -80.1 dBc/Hz at 1 MHz offset from the highest frequency carrier (56.16 GHz). The output spectrum shows a reference spur attenuation of -32 dBc. The high data rate CDR features a maximum operating data rate in excess of 3.456 Gb/s while consuming 30 mW of power. The low power CDR consumes only 5 mW and operates at a maximum data rate of 1.728 Gb/s. Over a 1.5 m 60 GHz wireless link, both CDRs allow 95% reduction of the pulse shaping generated input peak-to-peak jitter from 450 ps down to 50 ps.

<p>It is relatively straightforward to establish equilibrium inmagnetically confined plasmas, but the plasma is frequentlysucceptible to a variety of instabilities that are driven bythe free energy in the magnetic field or in the pressuregradient. These unstable modes exhibit effects that affect theparticle, momentum and heat confinement properties of theconfiguration. Studies of the dynamics of several of the mostimportant modes are the subject of this thesis. The studies arecarried out on plasmas in the reversed field pinch (RFP)configuration.</p><p>One phenomenon commonly observed in RFPs is mode walllocking. The localized nature of these phase- and wall lockedstructures results in localized power loads on the wall whichare detrimental for confinement. A detailed study of the walllocked mode phenomenon is performed based on magneticmeasurements from three RFP devices. The two possiblemechanisms for wall locking are investigated. Locking as aresult of tearing modes interacting with a static field errorand locking due to the presence of a non-ideal boundary. Thecharacteristics of the wall locked mode are qualitativelysimilar in a device with a conducting shell system (TPE-RX)compared to a device with a resistive shell (Extrap T2). Atheoretical model is used for evaluating the threshold valuesfor wall locking due to eddy currents in the vacuum vessel inthese devices. A good correlation with experiment is observedfor the conducting shell device.</p><p>The possibility of succesfully sustaining discharges in aresistive shell RFP is introduced in the recently rebuiltdevice Extrap T2R. Fast spontaneous mode rotation is observed,resulting in low magnetic fluctuations, low loop voltage andimproved confinement. Wall locking is rarely observed. The lowtearingmode amplitudes allow for the theoretically predictedinternal nonresonant on-axis resistive wall modes to beobserved. These modes have not previously been distinguisheddue to the formation of wall locked modes. The internal andexternal nonresonant resistive wall modes grow on the timescale of the shell penetration time. These growth rates dependon the RFP equilibrium. The internal nonresonant resistive wallmodes dominate in Extrap T2R, especially for shallow reverseddischarges. The external nonresonant modes grow solely in deepreversal discharges.</p><p><b>Keywords</b>Nuclear fusion, reversed field pinch, resistiveinstabilities, wall locked modes, tearing modes, resistiveshell modes, field errors, EXTRAP-T2, EXTRAP-T2R, TPE-RX</p>