Asad Abidi

Resonant Circuit Oscillators: How they Work, why they are Imperfect

March 31, 2011, at 3 p.m. in SF1105

Abstact: Every electronic system that processes signals must have references built into it that define a scale for amplitude and time. A local oscillator serves as the time reference, and except in some rudimentary uses, it is based on a resonator. The principles for the oscillator are the same, whether it uses a quartz crystal, an inductor-capacitor tank, or a machined cavity as the resonator.

In this talk I will describe the electronic circuit that develops oscillatory power from these resonators, and show in simple but accurate terms how oscillation starts and settles into steady-state. This necessarily involves a discussion of nonlinearity. Fluctuations in the circuit’s currents and voltages introduce what is termed phase noise and jitter, and I will show that these can be predicted without too much fuss.

The presentation is suited to EE undergraduates and graduate students who know basic signal theory and simple transistor circuits.

Bio: Asad Abidi received the BSc degree in Electrical Engineering from Imperial College, London in 1976, and the PhD from the University of California, Berkeley in 1982. He worked at Bell Laboratories, Murray Hill until 1985 developing the first generation of NMOS front-ends for optical receivers at bandwidths in excess of 1 GHz, and then joined the faculty of the University of California, Los Angeles. With his students he has developed many of the circuits and architectures that define today’s commercial RF-CMOS ICs, and where he teaches courses in analog and RF IC design and basic circuit theory.

Abidi received the 2008 IEEE Donald O. Pederson Award in Solid-State Circuits. He is a Fellow of IEEE, Associate Fellow of TWAS--the science academy of the developing world, and Member of the US National Academy of Engineering.  Abidi is a professor of electrical engineering at the University of California, Los Angeles.