Statistical electronics: Noise processes in integrated communication systems

This thesis presents a comprehensive investigation of noise and thermodynamics in electronic circuits and systems. This study of “statistical electronics” spans two disciplines, statistical thermodynamics and electronic circuit engineering, and leads to a general picture that bridges electronics and statistical thermodynamics.; Our work on statistical electronics has both scientific and engineering implications. Scientifically, this work is an extensive study of statistical thermodynamics in the context of electrical circuits, which has made several significant contributions to the understanding of noise processes in electrical circuits. The technological importance is a demonstration of how the fundamental physical considerations evolve to practical high-performance novel circuit design. The power of our fundamental approach is demonstrated through several practical circuit examples.; First, our investigation of fluctuations in nonlinear electrical circuits provides deep insight into the nonlinear fluctuation phenomena. Especially, the study of fluctuations in nonlinear active devices constitutes an important sector in this investigation, verifying the physical soundness of the contemporary active device noise modeling and leading to clear understanding of fluctuation-dissipation relations in nonlinear devices.; Second, we apply statistical electronics to noise problems involved in frequency conversion, an essential function in modern RF and microwave receivers. This study leads to two novel observations of noise figure degradation due to cyclostationary noise and conversion gain enhancement, both dependent on the size of energy storing elements. This novel behavior is experimentally verified with a direct measurement of integrated switching mixers. The results provide new insight into cyclostationary noise processes in frequency conversion and optimum design for switching mixers.; Third, application of statistical electronics to noise in frequency generation by self-sustained oscillators leads to a new theory of oscillator noise. This study demonstrates the direct correspondence between the phase noise and the Einstein relation, revealing the underlying physics of oscillator noise. Our approach clarifies the fluctuation-dissipation relation in oscillator noise generation, establishing a link between currently available fluctuation-based and dissipation-based phase noise models and leading to a clear definition of loaded quality factor of an oscillator. The novel concepts of virtual damping and linewidth compression put resonators and oscillators in a unified framework, providing immediate design optimization insight. The power of this theoretical development is demonstrated through experimental measurements of various integrated oscillators.; Our work on statistical electronics combining circuit engineering and physical science has also resulted in other useful engineering methods, such as graphical optimization, noise simulations for computer-aided design (CAD), and time-varying filter theory.