Fully Integrated Phase Noise Extraction and Cancellation Technique for Ring-Oscillator Based Fractional-N PLLs

November 13, 2013
Mudd 227
Hosted by: Yannis Tsividis
Speaker: Bertan Bakkaloglu , Associate Professor, Arizona State University


Ring-oscillators (ROs) provide a low-cost digital VCO solution in fully integrated PLLs. However due to their supply noise sensitivity and high noise floor, their applications have been limited to low performance applications. The proposed architecture introduces an analog feed-forward adaptive phase noise cancellation architecture that extracts and suppresses phase noise of ring-oscillators outside the PLL bandwidth. The proposed technique can improve the phase noise at an arbitrary offset frequency and bandwidth, and after initial calibration for gain it is insensitive to process, voltage and temperature variations. An experimental fractional PLL, with a loop bandwidth of 200 kHz is utilized to demonstrate the active phase noise cancellation approach. The cancellation loop is designed to suppress the phase noise at 1 MHz offset by 12.5 dB and reference spur by 13 dB with less than 17% increase in the overall power consumption at 5.1 GHz frequency. The measured phase noise at 1 MHz offset after cancellation is -105 dBc/Hz.

Speaker Bio

Dr. Bakkaloglu received his PhD from Oregon State University in 1995 and joined Texas Instruments Inc. Mixed Signal Wireless Design Group, Dallas, TX, where he worked on analog, RF and mixed signal front ends for wireless and wireline communication ICs. He worked on system-on-chip designs with integrated battery management and RF, analog baseband functionality as a design leader. In 2004 he joined the Electrical Engineering Department at Arizona State University, Tempe, AZ, as an associate professor. His research interests include mixed signal circuit design for supply regulators, biomedical, chemical and MEMS sensor interface circuits, fractional-N frequency synthesizers, high speed data converters and built-in-self-diagnostic circuits for high reliability mixed signal circuits. Dr. Bakkaloglu has been associate editor for IEEE Transactions on Circuits and Systems and currently an associate editor for IEEE Transactions on Microwave Theory and Techniques. He is the Technical Program Committee Chair for 2014 RFIC Symposium.

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