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Deterministic jitter in broadband communication

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  • Communication
  • Design
  • Physics


The past decade has witnessed a drastic change in the design of high-speed serial links. While Silicon fabrication technology has produced smaller, faster transistors, transmission line interconnects between chips and through backplanes have not substantially improved and have a practical bandwidth of around 3GHz. As serial link speeds increase, new techniques must be introduced to overcome the bandwidth limitation and maintain digital signal integrity. This thesis studies timing issues pertaining to bandwidth-limited interconnects. Jitter is defined as the timing uncertainty at a threshold used to detect the digital signal. Reliable digital communication requires minimizing jitter. The analysis and modeling presented here focuses on two types of deterministic jitter. First, dispersion of the digital signal in a bandwidth-limited channel creates data-dependent jitter. Our analysis links data sequences to unique timing deviations through the channel response and is shown for general linear time-invariant systems. A Markov model is constructed to study the impact of jitter on the operation of the serial link and provide insight in circuit performance. Second, an analysis of bounded-uncorrected jitter resulting from crosstalk induced in parallel serial links is presented. Timing equalization is introduced to improve the signal integrity of high-speed links. The analysis of deterministic jitter leads to novel techniques for compensating the timing ambiguity in the received data. Data-dependent jitter equalization is discussed at both the receiver, where it complements the operation of clock and data recovery circuits, and as a phase pre-emphasis technique. Crosstalk-induced, bounded-uncorrected jitter can also be compensated. By detecting electromagnetic modes between neighboring serial links, a transmitter or receiver anticipates the timing deviation that has occurred along the transmission line. Finally, we discuss a new circuit technique for submillimeter integrated circuits. Demands of wireless communication and the high speed of Silicon Germanium transistors provide opportunities for unique radio architectures for submillimeter integrated circuits. Scalable, fully-integrated phased arrays control a radiated beam pattern electronically through tiling multiple chips. Coupled-oscillator arrays are used for the first time to subharmonically injection-lock across a chip or between multiple chips to provide phase coherence across an array.

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