Architectures and Enhanced Frequency Synthesizer
نویسندگان
چکیده
Oscillator Architectures and Enhanced Frequency Synthesizer. (December 2009) Sang Wook Park, B.S., Yonsei University, Korea; M.S., Yonsei University, Korea Chair of Advisory Committee: Dr. Edgar Sánchez-Sinencio A voltage controlled oscillator (VCO) that generates a periodic signal whose frequency is tuned by a voltage is a key building block in any integrated circuit system. A sine wave oscillator can be used for a built-in self testing where high linearity is required. A bandpass filter (BPF) based oscillator is a preferred solution, and high quality factor (Q-factor) is needed to improve the linearity. However, a stringent linearity specification may require very high Q-factor, and is not practical to implement. To address this problem, a frequency harmonic shaping technique is proposed. It utilizes a finite impulse response filter improving the linearity by rejecting certain harmonics. A prototype SC BPF oscillator with an oscillating frequency of 10 MHz is designed and measurement results show that linearity is improved by 20 dB over a conventional oscillator. In radio frequency area, preferred oscillator structures are an LC oscillator and a ring oscillator. An LC oscillator exhibits good phase noise but an expensive cost of an inductor is disadvantageous. A ring oscillator can be built in standard CMOS process, but suffers due to a poor phase noise and is sensitive to supply noise. An RC BPF
منابع مشابه
Digital Fractional Frequency Synthesizer Based on Counters
This paper describes the architecture of a new pure digital frequency synthesizer based on pulse generators, counters and a register. The technique described here is much simpler than other methods. The synthesizer presented is suitable for the design of VLSI architectures or for programmable large-scale integration circuits.
متن کاملA Digitally-enhanced Delta-sigma Fractional-N Synthesizer
Recent advances in frequency synthesizer architectures have formed the groundwork for a very exciting and active area of research. On the one hand, the need for a wider-bandwidth fractional-N synthesizer has inspired researchers to develop phase noise cancellation techniques to avoid tradeoffs between noise performance and synthesizer bandwidth [1], as shown in Figure 1. On the other hand, the ...
متن کاملA New Architecture of Digital Frequency Synthesizer
Frequency synthesis has many applications in today’s commercial electronic and telecommunications system design. Some techniques exist which can be used to generate a frequency that is an integer or fractional multiple of a reference frequency. This paper describes architecture a new pure digital frequency synthesizer based on generators, counters and a register. The technique described here is...
متن کاملPll Based Frequency Synthesizer Implemented with an Active Inductor Oscillator
High costs, bulkiness, and larger power consumption makes transceiver integration and miniaturization a desired option to discretely implemented transceivers. Furthermore, a frequency synthesizer forms an important part of high-frequency transceivers. In this paper, the design of a fully-integrated dual loop frequency synthesizer is detailed. Previously, frequency synthesizers have already been...
متن کامل