PhD Alumni

Madoglio Paolo

Present position: Research Scientist, Intel Coporation, Hillsboro OR - U.S.A.

Thesis title:  Time-to-Digital Converters for Digitally-Enhanced RF Frequency Synthesis
Advisor:  Andrea Lacaita
Research area:  Microelectronics and Emerging Technologies
Thesis abstract:  
new trend of digital-style design has been growing up for the latest years in the field of integrated circuits. Digital-style design aims at replacing analog intensive blocks with simpler analog blocks whose inferior performances are compensated by digital calibrations. A main advantage of digital-style design over the traditional analog-based one is the better scalability into new technologies; in fact calibration algorithms do not need to be redesigned any times they are implemented in a new technology. Another advantage of the digital-style design is the possibility to reconfigure the circuits for different communication standards: the digital-style design is a step towards the implementation of the so-called 'Software Defined Radio', a radio using the same circuitry adapted through digital settings to any communication standard.

Moreover in recent year a new paradigm has been proposed: in the modern ultra-scaled CMOS technologies working with digital waveforms storing the useful information in their reciprocal delay is more accurate than working with analog voltages.

The present Ph.D. work deals with the application of the digital-style methodology and of the new paradigm to the problem of the frequency synthesis in RF transceivers. Time-to-Digital Converters (TDC) prove to be the key building blocks to the application of the two new design methodologies mentioned above: in fact they work with time delays (rather than with analog voltages) and they provide a digital information useful to run calibrations. The thesis presents two applications of TDCs in the field of the frequency synthesis. The first application of TDC is the calibration of time mismatch between the input phases of a phase-switching fractional frequency divider. The second application of TDCs is the implementation of a digitally-controlled Phase-Locked Loop (PLL).