| Summary: | 碩士 === 國立臺灣大學 === 電機工程學研究所 === 88 === The goal of this work is to use standard CMOS processes to implement a RF frequency synthesizer which employs an monolithic LC-tank voltage-controlled oscillator. This thesis is divided into two parts. The first part includes Chapter 2 and Chapter 3, in which the operation mechanisms and related analysis of phase-locked loops (PLL''s) and voltage-controlled oscillators (VCO''s) are presented. Chapter 4 and Chapter 5 consistute the second part and present the implementations of monolithic LC-tank VCO''s and a RF frequency synthesizer, respectively.
PLL-based frequency synthesizers are introduced in Chapter 2. The design procedures of charge-pump PLL''s are presented thereafter. Architecture simulation with MATLAB is introduced, too.
The implementations of monolithic VCO''s are the most challenging tasks in this work and thus Chapter 3 introduces the most common types of VCO: the ring oscillator, the relaxation oscillator and LC-tank oscillator. Phase noise performances of these three kinds of VCO are analyzed and compared.
Chapter 4, which presents the implementations of LC-tank VCO''s, is divided into four sections. The first section introduces some basic ideas of high-frequency device characterization. The second and third section present the key devices in LC-tank VOC''s: spiral inductors and varactors, respectively. The four VCO''s implemented and measured are presented in the last section.
The implementation of the frequency synthesizer is presented in Chapter 5. While the employed VCO is discussed previously in Chapter 4, the rest building blocks including phase/frequency detector, charge pump, loop filter, prescaler and feedback divider are discussed here. Achieving higher operating frequencies and lower power consumption, a new prescaler is presented in comparison with the conventional one. Since it employs the idea of fractional division, it is called the fractional prescaler. The measurement results of the fractional prescaler reveal some problems, which are corrected in the second version. Finally, a complete frequency synthesizer with an on-chip VCO is designed, implemented and measured.
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