Omar Abdel Fattah
Published: 2016
Total Pages:
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"Frequency synthesizers based on phase-locked loop (PLL) are ubiquitous components in RF communication systems. Frequency synthesizer PLLs must comply with the stringent requirements of RF systems such as noise, linearity, locking time, stability, and power consumption. The continuous shrinkage of the technology dimensions and power supply values exacerbated the situation and made the design more daunting especially at high frequencies. Integrability and long-life batteries have become extremely important targets in modern life. The ability to incorporate multiple standards in one device has recently stimulated a great deal of interest and brought to existence applications such as software-defined radio (SDR) and cognitive radio (CR). Such applications require very wide tuning range frequency synthesizers to cover multiple standards. The ability to cover this wide range with a single frequency synthesizer PLL is very desirable in terms of cost, area, and power. In this thesis, we tackle high frequency synthesis in light of the challenges imposed by modern CMOS technologies. More specifically, we tackle two design challenges. The first challenge is the need for wide tuning-range frequency synthesizer PLLs; and the second challenge is the need for analog circuits, including frequency synthesizer PLLs, that can operate from supply voltages below 0.6 V as predicted by semiconductor roadmaps for the next decade. In response to these technology demands, we provide three different IC implementations with measurement results to verify the theoretical findings. We demonstrate two frequency synthesizer PLLs in 65 nm CMOS technology. The first PLL focuses on wide tuning-range for applications such as SDR and CR, while operating from a supply voltage as low as 1.2 V. A continuous frequency range from 156.25 MHz to 10 GHz is achieved using a single frequency synthesizer PLL. The second PLL focuses on sub-1 V operation to generate a low-noise output. This PLL operates from a 0.55 V power supply and consumes 3 mW of power. The designed PLLs show comparable performance with the state-of-the-art PLLs in the literature in CMOS and other technologies. Furthermore, a third IC implementation of an ultra-low-voltage operational-transconductance-amplifier (OTA) is presented. The OTA combines different low-voltage techniques along with a novel biasing technique that allows operation from a supply voltage as low as 0.35 V. The ultra-low-voltage OTA can be used as a building block for the design of other biasing circuitry at low voltage such as bandgap references and voltage regulators." --