Thesis (M. S.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008. / Committee Chair: Laskar Joy; Committee Member: Cressler John; Committee Member: Tentzeris Emmanouil

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references. Also available in electronic version.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

Abstract This thesis studies the level of performance achievable using today's standard IC processes in the integrated RF subcircuits of the modern GSM base station. The thesis concentrates on those circuit functions, i.e. I/Q modulators, variable gain amplifiers and frequency synthesizers, most relevant for integration in the base station environment as pinpointed by studying the receiver/transmitter architectures available today. Several RF integrated circuits have been designed, fabricated and their level of performance measured. All main circuits were fabricated in a standard double-metal double-poly 1.2 and 0.8 μm BiCMOS process. Key circuit structures and their measured properties are: 90° phase shifter with ±1° phase error with VCC = 4.5…5.5 V and T = -10…+85 °C, I/Q modulator suitable for operation at output frequencies from 100 MHz to 1 GHz and baseband frequencies from 60 to 500 kHz (2.0 mm × 2.0 mm, 100 mA, 5.0 V) with LO suppression of 38 dBc and image rejection of 41 dBc, temperature compensated DC to 1.5 GHz variable gain amplifier (1.15 mm × 2.00 mm, 100 mA, 5.0 V) with a linear 50 dB gain adjustment range, maximum gain of 18.5 dB and gain variation of 1 dB up to 700 MHz over the whole operating conditions range of VCC = 4.5…5.5 V and T = -10…+85 °C, a complete bipolar semicustom synthesizer (90…122 mA, 5.0 V) and two complete full-custom BiCMOS synthesizer chips including all building blocks of a PLL-based synthesizer except for the voltage controlled oscillator and the loop filter. The synthesizers include circuit structures such as ∼2 GHz multi-modulus divider and low-noise programmable phase detector/charge pump (18.7 pA/√Hz at Iout = 500 μA) and have an exemplar phase noise performance of -110 dBc/Hz at 200 kHz offset. One of the main problems of the integer-N PLL based synthesizer when used in a multichannel telecommunications system is the level of spurious signals at the output, when the synthesizer is optimised for fast frequency switching. Therefore, a method using only two current pulses to make the frequency step response of the loop faster, thus allowing a narrower loop bandwidth to be used for additional spur suppression, is proposed. The operation of the proposed speed-up method is analysed mathematically and verified by measurements of an existing RF-IC synthesizer operating at 800 MHz. Measurements show that simple current pulses can be used to speed up the channel switching of a practical RF synthesizer having a frequency step time in the tens of μs range. In the example, a 7.65 MHz frequency step was made seven times faster using the proposed method.

This thesis presents research into ultra-low noise photonic microwave synthesis and the development of a novel, frequency comb-based, fibre optic time transfer technique. The focus in the first area is on reducing the noise introduced in the optical-to- electrical conversion process using balanced optical-microwave phase detectors. Two mainly free-space and two mainly fibre-based devices were built and their performance was characterised. The phase noise of the optical-to-electrical conversion of the free-space device was -119 dBc Hz⁻¹ at 1 Hz and -143 dBc Hz⁻¹ at 20 kHz from an 8 GHz carrier which is the best performance reported for a free-space balanced-optical microwave phase detector. The improved fibre-based set-ups demonstrated a state-of-the-art amplitude-to-phase noise suppression of 60 dB and a phase noise of the optical-to-electrical conversion of -131 dBc Hz⁻¹ at 1 Hz and 148 dBc Hz⁻¹ at 20 kHz from an 8 GHz carrier. The novel time transfer technique developed in the second part superimposes timing information onto the optical pulse train of an ITU-channel-filtered frequency comb using an intensity modulation scheme. Time transfer over a 50 km long, delay-stabilised fibre spool produced a state-of-the-art time deviation of 300 fs and an accuracy of approximately 0.01 ns which is close to the best performance achieved using amplitude modulated cw lasers. Using this technique on a 159 km long installed fibre link between NPL and Reading, the same time deviation was achieved and an accuracy of approximately 0.08 ns was obtained, limited by uncertainty of the time interval counter. Using the same fibre link, microwave frequency transfer of the ITU-channel-filtered comb was demonstrated with a fractional frequency instability of 2x10⁻¹⁷ at 5000 s which is approximately at the same level as the best previously reported results which were obtained with a 30 nm wide optical frequency comb.

This thesis describes the design, implementation and testing of a UHF frequency synthesizer. The synthesizer is designed to provide a sine wave output programmable from 400 MHz to 500 MHz in 0.1 MHz increments. The synthesis technique utilized is Digital Coherent Indirect Synthesis. This technique uses phase locking to provide a range of stable output frequencies all derived from a single crystal reference. Component design and system level analysis are presented in detail.

by C.Y. Ho. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1989. / Bibliography: leaves [147]-[148]

The need for clean and powerful signal generation is ubiquitous, with applications spanning the spectrum from RF to mm-Wave, to into and beyond the terahertz-gap. RF applications including mobile telephony and microprocessors have effectively harnessed mixed-signal integration in CMOS to realize robust on-chip signal sources calibrated against adverse ambient conditions. Combined with low cost and high yield, the CMOS component of hand-held devices costs a few cents per part per million parts. This low cost, and integrated digital processing, make CMOS an attractive option for applications like high-resolution imaging and ranging, and the emerging 5-G communication space. RADAR techniques when expanded to optical frequencies can enable micrometers of resolution for 3D imaging. These applications, however, impose upto 100x more exacting specifications on power and spectral purity at much higher frequencies than conventional RF synthesizers. This generation of applications will present unconventional challenges for transistor technologies - whether it is to squeeze performance in the conventionally used spectrum, already wrung dry, or signal generation and system design in the relatively emptier mm-Wave to sub-mmWave spectrum, much of the latter falling in the ``Terahertz Gap". Indeed, transistor scaling and innovative device physics leading to new transistor topologies have yielded higher cut-off frequencies in CMOS, though still lagging well behind SiGe and III-V semiconductors. To avoid multimodule solutions with functionality partitioned across different technologies, CMOS must be pushed out of its comfort zone, and technology scaling has to have accompanying breakthroughs in design approaches not only at the system but also at the block level. In this thesis, while not targeting a specific application, we seek to formulate the obstacles in synthesizing high frequency, high power and low noise signals in CMOS and construct a coherent design methodology to address them. Based on this, three novel prototypes to overcome the limiting factors in each case are presented. The first half of this thesis deals with high frequency signal synthesis and power generation in CMOS. Outside the range of frequencies where the transistor has gain, frequency generation necessitates harmonic extraction either as harmonic oscillators or as frequency multipliers. We augment the traditional maximum oscillation frequency metric (fmax), which only accounts for transistor losses, with passive component loss to derive an effective fmax metric. We then present a methodology for building oscillators at this fmax, the Maximum Gain Ring Oscillator. Next, we explore generating large signals beyond fmax through harmonic extraction in multipliers. Applying concepts of waveform shaping, we demonstrate a Power Mixer that engineers transistor nonlinearity by manipulating the amplitudes and relative phase shifts of different device nodes to maximize performance at a specific harmonic beyond device cut-off. The second half proposes a new architecture for an ultra-low noise phase-locked loop (PLL), the Reference-Sampling PLL. In conventional PLLs, a noisy buffer converts the slow, low-noise sine-wave reference signal to a jittery square-wave clock against which the phase of a noisy voltage-controlled oscillator (VCO) is corrected. We eliminate this reference buffer, and measure phase error by sampling the reference sine-wave with the 50x faster VCO waveform already available on chip, and selecting the relevant sample with voltage proportional to phase error. By avoiding the N-squared multiplication of the high-power reference buffer noise, and directly using voltage-mode phase error to control the VCO, we eliminate several noisy components in the controlling loop for ultra-low integrated jitter for a given power consumption. Further, isolation of the VCO tank from any varying load, unlike other contemporary divider-less PLL architectures, results in an architecture with record performance in the low-noise and low-spur space. We conclude with work that brings together concepts developed for clean, high-power signal generation towards a hybrid CMOS-Optical approach to Frequency-Modulated Continuous-Wave (FMCW) Light-Detection-And-Ranging (LIDAR). Cost-effective tunable lasers are temperature-sensitive and have nonlinear tuning profiles, rendering precise frequency modulations or 'chirps' untenable. Locking them to an electronic reference through an electro-optic PLL, and electronically calibrating the control signal for nonlinearity and ambient sensitivity, can make such chirps possible. Approaches that build on the body of advances in electrical PLLs to control the performance, and ease the specification on the design of optical systems are proposed. Eventually, we seek to leverage the twin advantages of silicon-intensive integration and low-cost high-yield towards developing a single-chip solution that uses on-chip signal processing and phased arrays to generate precise and robust chirps for an electronically-steerable fine LIDAR beam.

Ng Chong Chon. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 100-103). / Abstract in English and Chinese. / 摘要 --- p.iii / Acknowledgments --- p.iv / Contents --- p.vi / List of Figures --- p.ix / List of Tables --- p.xii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Thesis Organization --- p.4 / Chapter Chapter 2 --- DMP Architecture --- p.6 / Chapter 2.1 --- Conventional DMP --- p.6 / Chapter 2.1.1 --- Operating Principle --- p.7 / Chapter 2.1.2 --- Disadvantages --- p.10 / Chapter 2.2 --- Pre-processing Clock Architecture --- p.10 / Chapter 2.2.1 --- Operating Principle --- p.11 / Chapter 2.2.2 --- Advantages and Disadvantages --- p.12 / Chapter 2.3 --- Phase-switching Architecture --- p.13 / Chapter 2.3.1 --- Operating Principle --- p.13 / Chapter 2.3.2 --- Advantages and Disadvantages --- p.14 / Chapter 2.4 --- Summary --- p.15 / Chapter Chapter 3 --- Full-Speed Divider Design --- p.16 / Chapter 3.1 --- Introduction --- p.16 / Chapter 3.2 --- Working Principle --- p.16 / Chapter 3.3 --- Design Issues --- p.18 / Chapter 3.4 --- Device Sizing --- p.19 / Chapter 3.5 --- Layout Considerations --- p.20 / Chapter 3.6 --- Input Sensitivity --- p.22 / Chapter 3.7 --- Modeling --- p.24 / Chapter 3.8 --- Review on Different Divider Designs --- p.28 / Chapter 3.8.1 --- Divider with Dynamic-Loading Technique --- p.28 / Chapter 3.8.2 --- Divider with Negative-Slew Technique --- p.30 / Chapter 3.8.3 --- LC Injection-Locked Frequency Divider --- p.32 / Chapter 3.8.4 --- Dynamic True Single Phase Clock Frequency Divider --- p.34 / Chapter 3.9 --- Summary --- p.42 / Chapter Chapter 4 --- 3V 900MHz Low Noise DMP --- p.43 / Chapter 4.1 --- Introduction --- p.43 / Chapter 4.2 --- Proposed DMP Topology --- p.46 / Chapter 4.3 --- Circuit Design and Implementation --- p.49 / Chapter 4.4 --- Simulation Results --- p.51 / Chapter 4.5 --- Summary --- p.53 / Chapter Chapter 5 --- 1.5V 2.4GHz Low Power DMP --- p.54 / Chapter 5.1 --- Introduction --- p.54 / Chapter 5.2 --- Proposed DMP Topology --- p.56 / Chapter 5.3 --- Circuit Design and Implementation --- p.59 / Chapter 5.3.1 --- Divide-by-4 stage --- p.59 / Chapter 5.3.2 --- TSPC dividers --- p.63 / Chapter 5.3.3 --- Phase-selection Network --- p.63 / Chapter 5.3.4 --- Mode-control Logic --- p.64 / Chapter 5.3.5 --- Duty-cycle Transformer --- p.65 / Chapter 5.3.6 --- Glitch Problem --- p.66 / Chapter 5.3.7 --- Phase-mismatch Problem --- p.70 / Chapter 5.4 --- Simulation Results --- p.70 / Chapter 5.5 --- Summary --- p.74 / Chapter Chapter 6 --- 1.5V 2.4GHz Wideband DMP --- p.75 / Chapter 6.1 --- Introduction --- p.75 / Chapter 6.2 --- Proposed DMP Architecture --- p.75 / Chapter 6.3 --- Divide-by-4 Stage --- p.76 / Chapter 6.3.1 --- Current-switch Combining --- p.76 / Chapter 6.3.2 --- Capacitive Load Reduction --- p.77 / Chapter 6.4 --- Simulation Results --- p.81 / Chapter 6.5 --- Summary --- p.83 / Chapter Chapter 7 --- Experimental Results --- p.84 / Chapter 7.1 --- Introduction --- p.84 / Chapter 7.2 --- Equipment Setup --- p.84 / Chapter 7.3 --- Measurement Results --- p.85 / Chapter 7.3.1 --- 3V 900GHz Low Noise DMP --- p.85 / Chapter 7.3.2 --- 1.5V 2.4GHz Low Power DMP --- p.88 / Chapter 7.3.3 --- 1.5V 2.4GHz Wideband DMP --- p.93 / Chapter 7.3 --- Summary --- p.96 / Chapter Chapter 8 --- Conclusions and Future Works --- p.98 / Chapter 8.1 --- Conclusions --- p.98 / Chapter 8.2 --- Future Works --- p.99 / References --- p.100 / Publications --- p.104