Education

• Ph.D., Electrical Engineering. Cornell University, 2011
• M.Sc., Electrical Engineering, University of Southern California, 2006
• B.Sc., Electrical Engineering, Isfahan University of Technology, 2002

Professional Experience

• Assistant Professor, University of California, Davis, 2011-Present
• Analog-RF IC Design Engineer, NASA-Jet Propulsion Laboratory, Pasadena, CA, 2004 - 2006

Research Interests

High performance terahertz and mm-wave integrated circuits and systems, High power/high efficiency power amplifiers and signal sources, RF/Microwave transceivers.

Research Activities

• Fundamental Limitations of Circuit Architectures:

  We develop theoretical frameworks for analyzing the fundamental frequency, power and noise limitations of various circuit architectures and exploit the results to design novel circuits with significantly better performance. Broadly speaking, the main innovation here is the introduction of a systematic methodology for designing circuits operating at the limits of the transistors in any given process. This is achieved by blending device physics, circuit theory, and high frequency circuit design into a coherent technique. In the context of signal generation, this method led to the implementation of a 482 GHz oscillator in a 65 nm CMOS process with an output power of 160 µW. In signal amplification domain, an amplifier was implemented with 12.5 dB of gain at 107 GHz in a 130 nm CMOS with fmax of ~135 GHz. This project is an example of looking into circuit design from a completely different angle to achieve what is otherwise impossible.
• Going Beyond the Conventional Limitations of Passive Circuits:

  We have introduced a methodology to perform high performance signal processing using 2-D electrical lattices. Using the anisotropic behavior of these lattices, we proposed an Electrical Prism that can achieve a filtering quality factor, which is orders of magnitude larger than the quality factor of the individual components in terahertz frequencies. An Electrical Prism with quality factor of 420 at 460 GHz consisting of elements with the quality factor 20 was presented.
• Traveling-Wave Circuits for Wide Band Signal Generation:

  Inspired by the Doppler effect and using the traveling-wave properties, we proposed a novel wideband frequency multiplier that efficiently generates and combines the harmonics of the input signal. The implemented frequency doubler operates from 220 GHz to 275 GHz in a 65 nm CMOS process with an output power of -6.6 dBm at 244 GHz.
• Terahertz System-on-Chip:

  Not too long ago, envisioning a CMOS terahertz system-on-chip did not seem realistic. This is about to change thanks to innovative circuit design methodologies and transistor scaling. For the first time, we have introduced a CMOS terahertz source that generates a useful amount of power for most terahertz applications. Other CMOS terahertz system blocks for signal amplification, signal processing (electrical prism), and signal synthesis (frequency multiplier) were also proposed. My group is working toward implementing the remaining building blocks such as phase-locked loops (PLL), and to efficiently connect them together for a complete CMOS terahertz system. Indeed, the same methodologies and techniques are exploited in compound semiconductors for even higher frequencies and better performances.

Distinctions

• Cornell ECE Best Ph.D. Thesis Award, 2011
• Outstanding Graduate Award from Association of Professors and Scholars of Iranian Heritage (APSIH), 2011
• Best paper award at the IEEE Workshop on Microwave Circuits, 2010
• Cornell University Jacobs Fellowship, 2007
• NASA-Jet Propulsion Laboratory Summer Fellowship, 2003

Selected Publications

1. O. Momeni and E. Afshari, “A Broadband mm-Wave and Terahertz Traveling-Wave Frequency Multiplier on CMOS,” IEEE Journal of Solid-State Circuits, Dec. 2011. (Invited)
2. O. Momeni and E. Afshari, “A High Gain 107 GHz Amplifier in 130 nm CMOS,” Custom Integrated Circuit Conference (CICC), Sep. 2011.
3. O. Momeni and E. Afshari, High Power Terahertz and Millimeter-Wave Oscillator Design: A Systematic Approach, IEEE Journal of Solid-State Circuits, Mar. 2011.
4. O. Momeni and E. Afshari, A 220-to-275GHz Traveling-Wave Frequency Doubler with -6.6dBm Power at 244GHz in 65nm CMOS, IEEE Int'l Solid-State Circuits Conference (ISSCC), Feb. 2011.
5. O. Momeni, H. Hashemi and E. Afshari, A 10-Gb/s Inductorless Transimpedance Amplifier, IEEE Transactions on Circuits and Systems II, Dec. 2010.
6. O. Momeni and E. Afshari, Electrical Prism: a High Quality Factor Filter for mm-Wave and Terahertz Frequencies, IEEE Transactions on Microwave Theory and Techniques, Nov. 2009.