Dr. Amany El Gouharyl
An analysis of phase noise in transformer-based dual-tank oscillators
Next generation wireless devices will be required to support a wide variety of commercial standards and operate over a wide range of frequency bands. Therefore, components that are capable of operating over ultra-wide frequency ranges are often required. One such major component in any communication system is oscillators. Furthermore, modern telecommunication standards require very low phase noise oscillators and, because of their outstanding noise performance, LC-oscillators, are a popular choice. Hence, a lot of effort has been invested in studying and improving the tuning range and the phase noise performance of LC oscillators. A popular architecture that is being utilized in the recent literature is the transformer-based (T-based) oscillator. T-based oscillators were introduced as a way of expanding the tuning range of LC-oscillators through dual-mode implementation. They have also been proposed for improving phase noise due to an enhanced quality factor. Yet, the phase noise analysis of T-based oscillators are generally lacking and equations that were derived for inductor-based (L-based) oscillators have been commonly adopted for T-based oscillators. The present analysis introduces a more accurate and complete phase noise analysis for T-based oscillators using the linear time variant model introduced by Hajimiri and Lee.
Amany El Gouhary received both the B.S. and M.E. degrees in electrical and computer engineering from the University of Utah, Salt Lake City in 2006 and 2008. She received the B.S. degree in computer science from the American University in Cairo, Egypt. Amany received the Ph.D. degree in electrical engineering from Iowa State University, Ames, IA, USA, in 2014. In 2010, She was awarded Texas Instruments scholarship. In 2011, Amany joined the op-amp team in Texas Instruments Inc., Tucson, AZ for four months in which she worked on improving the band-width and performance of a general purpose op-amp. Her research interests include analog/RF circuits for cognitive radio, with emphasis on LC-VCOs.
Invited by Professor Slim Boumaiza