Scalable Array Transceivers with Wide Frequency Tuning Range for Next Generation Radios

Scalable array transceivers with wide frequency tuning range are attractive for next-generationradios. Key challenges for such radios include generation of LO signals with widefrequency tuning range, scalable synchronization between multiple array unit cells andtolerance to in-band and out-of-band interferers. This thesis presents approaches toaddress these challenges in commercial CMOS technologies.The first part focuses on a series resonant mode-switching VCO architecture thatachieves both state-of-art area and power efficiency with an octave frequency tuningrange from 6.4-14 GHz achieved 186-dB-188-dB Figure-of-Merit (FoM) in 65 nm CMOStechnology. The scalability of this approach towards achieving even larger FTR is alsodemonstrated by a triple-mode 2.2 GHz to 8.7 GHz (119% FTR) CMOS VCO.In the second part a scalable, single-wire coupled-PLL architecture for RF mm-wavearrays is presented. The proposed architecture preserves the simplicity of a daisy-chained LO distribution, compensates for phase offset due to interconnect, and provides phasenoise improvement commensurate to the number of coupled PLLs. Measurements on a28 GHz CMOS prototype demonstrate the feasibility of this scheme.The third part of this thesis presents filtering techniques for in-band blocker suppression.A spatial spectral notch filter design for MIMO digital beam forming arrays is proposedto relax the ADC dynamic range requirement. Orthogonal properties of Walsh functionsincorporated into passive N-path approach enables reconfigurable notches at multiplefrequencies and angles-of-incidence. A 0.3 GHz-1.4 GHz four-element array prototypeimplemented in 65 nm CMOS achieves > 15-dB notch filtering at RF input for twoblockers while causing < 3-dB NF degradation.Finally, a code-domain N-path receiver (RX) is proposed based on pseudo-random(PN) code-modulated LO pulses for simultaneous transmission and reception (STAR)applications. A combination of Walsh-Function and PN sequence is proposed to createcode-domain matched filter at the RF frontend which reflects unknown in-band blockersand rejects known in-band TX self-interference (SI) by using orthogonal codes at RXinput thereby maximizing the SNR of the received signals. The resulting prototype in65 nm is functional from 0.3 GHz-1.4 GHz with 35 dB gain and concurrently receivestwo code-modulated signals. Proposed transmitter (TX) SI mitigation approach resultsin 38.5 dB rejection for -11.8 dBm 1.46 Mb s QPSK modulated SI at RX input. TheRX achieves 23.7 dBm OP1dB for in-band SI, while consuming ∼35 mW and occupies0.31 mm2Keywords: Passive Mixers, dual band, TX self-Interferer, synchronisation, STAR, Code domain N-path receiver, mode switching, notch filter, Phase locked loops, Octave tuning range, CMOS, phase noise, VCO, large-scale 5G mm-wave arrays, resonator, Simultaneous transmit and receive, resonator band-switching, LO distribution, scalable coupled-PLL, N-path passive mixers, MIMO arrays, digital beamforming, CDMA, phased arrays, wide tuning range, Walsh Functio

Wideband Low Noise Oscillator suitable for Injection Locking

There is a growing need to design compact and low power transceiver circuits. The increasingly crowded frequency spectrum leads to increased challenges associated with transceiver design. In particular, it becomes imperative that the oscillator circuits have a low phase noise. RC oscillators have the ability to produce wideband oscillations with reduced area and low power consumption. However, a serious drawback is its high phase noise, which leads to poor circuit performance. To improve the performance of an RC oscillator, it is common for it to be integrated into a frequency synthesizer. The most common approach of a synthesizer is the Phase- Locked Loop (PLL). This approach leads to an increase in the area and complexity of the circuit. Another approach to a synthesizer is an Injection-Locked Oscillator (ILO), which achieves similar performances to a PLL without the disadvantages referred to above. In this thesis, an ILO based on an RC oscillator, using a Spin Torque Oscillator (STO) as a reference generator, is presented. The circuit is implemented in two different Complementary Metal-Oxide-Semiconductor (CMOS) technologies: 130 nm CMOS and 180 nm CMOS. The STO used as reference has characteristics similar to a nanometric device developed at the International Iberian Nanotechnology Laboratory (INL). In addition, the ILO operates in a wide frequency band ranging from 100 MHz to 3 GHz, has a power consumption ranging from 2.94 mW to 6.81 mW for 130 nm CMOS technology, whereas in 180nm CMOS technology it consumes between 4.86 mW and 13.96 mW. Thus, the work developed in the course of this thesis serves as proof of concept for the manufacture of a fully integrated hybrid ILO using the STO technology in conjunction with CMOS circuits

Resonance Over Resolution: Resisting Definition in Susan Howe, Nathaniel Mackey, and Ed Roberson's Post-1968 Poetics

In this dissertation on contemporary U.S. literature, I situate the poetry of Susan Howe, Nathaniel Mackey, and Ed Roberson within post-1968 leftist projects that share a common liberatory impulse. I mark the period of cultural production over the past fifty years by the term “post-1968” in order to evoke the popular imagination of “the sixties” as a time of revolutionary action that came to both real and imagined conclusions in 1968 in the U.S., France, China, Mexico, and elsewhere. In response, I argue, post-1968 writers developed a poetics based in cautiousness, wary of the double-edged danger of the tools we deploy toward social transformation. I insist that by doing so, their move from direct action to study represents a continuation rather than a departure from the liberatory projects that precede (and succeed) them, even as their political-aesthetic strategies shift from the certainty of resolute political visions toward the uncertainty of a politics of plurality. In the dissertation’s chapters, I excavate the ways Howe, Mackey, and Roberson’s post-1968 poetics draws on diverse cultural traditions to document American experience in ways that challenge formal convention—in their use of diction, syntax, and narrative, as well as historiography, literary study, and critical argument—while allowing multiple and often contradictory meanings to resonate with one another in cross-cultural relation, rather than resolve into single definitions that privilege one culture of meaning over another. Furthermore, by practicing a liberatory poetics with historical consciousness, they re-vision the American landscape as one haunted by the history of global capitalism, colonialism, and slavery during an age in which this history was increasingly obscured. By bringing Howe, Mackey, and Roberson’s work into literary-historical relation, I highlight a liberatory impulse and sensibility that was moving through the post-1968 period not otherwise accounted for by the existing narratives of innovative, experimental, avant-garde and oppositional poetry. By showing that what makes their individual work distinctive while charting a shared set of concerns and innovations, I make visible a wider field of liberatory poetic practice characterized by a commitment to resonance over resolution by resisting definition.Doctor of Philosoph

Synthetic and catalytic studies of Group 11 N-heterocyclic carbene complexes

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2006.Vita.Includes bibliographical references.This thesis presents the synthesis, structure and reactivity of two-coordinate Group 11 metal complexes, supported by N-heterocyclic carbene (NHC) ligands. The NHC ligand was found to stabilize monomeric, terminal fluoride complexes of copper, silver and gold, the last representing the first isolable gold(I) fluoride. These complexes were shown to be reactive synthons for new metal complexes. The ability of the NHC ligand to support unusual coordination environments for these metals inspired us to explore the chemistry of copper(I) bonded to various main group elements, leading to the development of new catalytic reactions. The first well-characterized copper(I) boryl complex was synthesized and shown to react with a variety of unsaturated organic substrates. This complex reacts rapidly with CO2 to form CO and a copper(I) borate complex. The boryl complex may be regenerated by treatment of the borate complex with the bis(pinacolato)diboron, (pin)B-B(pin), giving the stable byproduct (pin)B-O-B(pin). The use of a copper(I) alkoxide precatalyst and stoichiometric diboron reagent results in catalytic reduction of CO2, with high turnover numbers (1000 per Cu) and frequencies (100 per Cu in 1 hour) depending on supporting ligand and reaction conditions.(cont.) Carbon dioxide also inserts into the Cu-Si bond of a copper silyl complex. The resulting complex evolves CO to give a copper siloxide complex. Mesitaldehyde inserts cleanly and selectively into the Cu-B bond of (NHC)CuB(pin), to form a B-O and a copper-carbon bond. This complex reacts with bis(pinacolato)diboron to regenerate (NHC)CuB(pin) and produce an aldehyde diboration product, in which a diboron reagent has been added across the C=O bond of mesitaldehyde. A copper boryl complex with a smaller NHC supporting ligand proved to be a much more effective diboration catalyst and a wide range of aldehydes react cleanly with bis(pinacolato)diboron. The insertion of alkenes into an (NHC)copper(I) boryl affords isolable -boroalkyl complexes in high yields; competition experiments using substituted styrenes show that electron-donating substituents slow the reaction. Although the insertion products are stable at ambient temperature, a P-hydride elimination/reinsertion sequence affords a rearranged a-boroalkyl complex on heating.by David S. Laitar.Ph.D

TDRSS telecommunications study. Phase 1: Final report

A parametric analysis of the telecommunications support capability of the Tracking and Data Relay Satellite System (TDRSS) was performed. Emphasis was placed on maximizing support capability provided to the user while minimizing impact on the user spacecraft. This study evaluates the present TDRSS configuration as presented in the TDRSS Definition Phase Study Report, December 1973 to determine potential changes for improving the overall performance. In addition, it provides specifications of the user transponder equipment to be used in the TDRSS

Synthesis and reactivity of N-heterocyclic carbine stabilised ruthenium and rhodium hydride complexes

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

High-frequency gas-discharge breakdown

"July 25, 1955." "This report is identical with material prepared for Handbuch der Physik, Volume XXII, 1955."Includes bibliographical references.Army Signal Corps Contract DA36-039 sc-42607 Project 132B Dept. of the Army Project 3-99-12-022Sanborn C. Brown

National Geodetic Satellite Program, Part 1

The work performed by individual contributors to the National Geodetic Satellite Program is presented. The purpose of the organization, the instruments used in obtaining the data, a description of the data itself, the theory used in processing the data, and evaluation of the results are detailed for the participating organizations

Broad-band microwave amplifier design considerations

Broad-band microwave integrated circuit (MIC) amplifier design is a complex, multi-disciplinary process. This work focuses on three important aspects: the behaviour of microstrip transmission lines, discontinuities, and related structures; the accurate measurement of components and devices mounted in microstrip circuits; and the circuit design methodology. Techniques for microstrip quasi-static analysis are reviewed in order to identify methods suitable for extension to deal with the effects of substrate anisotropy. An integral equation method is described and the anisotropic Green's function derived using an extension to the method of partial images. Proposed transform methods are assessed and the preferred option implemented by adaption of a microstrip analysis computer program. A method, by which accurate measurements of microstrip properties may be made, is developed. Involving measurements of the resonant behaviour of half-wavelength short circuit resonators with two arbitrary coupling conditions, this technique allows the unloaded properties to be deduced. Results for microstrip on a sapphire substrate concur with the analysis. A pragmatic but effective approach to the calculation of the capacity component of microstrip discontinuities, and some other three dimensional MIC structures, is described and developed to allow existing data for isotropic substrates to be applied to the anisotropic situation. The computer corrected network analyser (CCNA) is a widely used microwave measurement tool. Weaknesses in popular correction strategies are identified and remedies developed. In particular, revised calibration equations that better accommodate test port mismatch variation with s-parameter selection, and a model for quadrature error are presented. A 2-port calibration scheme suitable for use with MIC transmission lines, using only simple standards, is described. The standards are partially self-calibrating;the values of propagation constant, loss, and end effect are deduced in the calibration process. An effective jig for use with microstrip is described and the results of measurements on microwave transistors presented. Conventionally microwave amplifiers are designed using reactive components both to achieve good port matches and compensate the frequency dependent gain of the active devices. The problems associated with this approach are enumerated and the alternatives reviewed. A methodology which combines the benefits of frequency dependant dissipative networks with the elegance of reactive network synthesis is described. The device gain slope is compensated by simple lumped or distributed circuits incorporating a resistive element to produce a composite `device' with a specififed (flat) maximum available gain frequency response. Reactive matching networks are then used to interface these gain blocks. By this structured approach the amplifier gain breakdown can be defined at the outset and preserved through the design process. Other advantages stemming from the use of dissipative compensation include improved tolerance to device parameter and component value scatter, reduced group delay variations and enhanced reverse isolation. The method is demonstrated by the design and characterisation of 4 to 9 GHz amplifier having a representative specification. The close conformance of the performance of the untrimmed amplifier to that predicted by computer simulation testifies to the inherent accuracy of the design method, the microstrip (and related structures) analysis techniques and the CCNA MIC calibration scheme