UNIC-YahyaTousi

Yahya Tousi

Ph.D., Cornell University

Research Interests

I am interested in the general area of high performance integrated circuits. My research employs several elements in electromagnetics, applied physics, and mathematics to push the envelope of electronic systems in terms of their frequency of operation, performance and computational power.
My research interests and contributions fall into the following areas:

Terahertz and mm-wave integrated circuits
Integrated electromagnetic signal generation and radiation
Non-linear dynamical systems in electronics
New platforms for analog signal processing including interferometric and time-based methods

Awards and Honors

IEEE SSCS Pre-Doctoral Achievement Award 2012
IEEE MTT Society Fellowship Award 2011
Winner of the IMS Graduate Research Competition 2011
Cornell University Jacobs Fellowship Award 2009

Selected Publications

Y. Tousi and E. Afshari, "A Scalable Terahertz 2-D Phased Array with +17dBm of EIRP at 338GHz in 65nm bulk CMOS", to appear in Proc. of IEEE Int'l Solid-State Circuits Conference (ISSCC), Feb. 2014.
Y. Tousi, V. Pourahmad, and E. Afshari, "Frequency Tuning of Terahertz Sources using Delay-Coupled Oscillators," Physical Review Letters, June 2012.
Y. Tousi, O. Momeni, and E. Afshari, "A 283-to-296GHz VCO with 0.76mW Peak Output Power in 65nm CMOS," in Proc. Of IEEE Int'l Solid-State Circuits Conference (ISSCC), Feb. 2012.
Y. Tousi and E. Afshari, "A Novel CMOS High-Power Terahertz VCO Based
on Coupled Oscillators: Theory and Implementation," IEEE Journal of Solid-State Circuits Special Issue Dec. 2012. (Invited)
Y. Tousi and E. Afshari, "A Miniature 2 mW 4 bit 1.2 GS/s Delay-Line-Based ADC in 65 nm CMOS," IEEE Journal of Solid-State Circuits, Oct. 2011.
Y. Tousi and E. Afshari, "2D Electrical Interferometer: A Novel High Speed
Quantizer," IEEE Transactions on Microwave Theory and Techniques, Oct. 2010.
G. Li, Y. Tousi, A. Hassibi, and E. Afshari, "Delay-line Based Analog-to-Digital Converters," IEEE Transactions on Circuits and Systems II, June 2009.
Y. Tousi, G. Li, A. Hassibi, and E. Afshari, "A 4-bit, 1mW Analog-to-Digital
Converter at 1GSample/sec," Proc. of IEEE International Symposium on Circuits and Systems, May 2009.
Y. Tousi and Ehsan Afshari, "Complex Scalable Networks of Electrical Oscillators", in preparation for Physical Review Letters
Y. Tousi and Ehsan Afshari, "CMOS Terahertz Phased Arrays for Scalable Signal Generation, Radiation, and Beam Steering", in preparation for IEEE Journal of Solid-State Circuits
Y. Tousi and E. Afshari, "Tunable Signal Source", US Patent Number 20,130,082,785, 2013.
Y. Tousi and E. Afshari, "Scalable Sources and Phased Arrays", Patent Pending

Research Highlights

Terahertz Radiation: A Scalable Approach

Can we use integrated circuits to generate and radiate meaningful power levels for terahertz applications? Inspired by the synchronization of oscillating networks I present a terahertz phased array radiator with an inherently scalable architecture. The measured EIRP of 50mW at 350GHz is by far the highest radiated power on any semiconductor technology (ISSCC '14).

High-Power Tunable Terahertz Signal Generation

How can we generate high output power from a harmonic oscillator above fmax and maintain our control on the center frequency? I introduce a new paradigm for VCO design that is based on a network of delay-coupled oscillators. In this structure the oscillator resonator is not loaded by lossy varactors. Instead, we control the frequency by manipulating the coupling dynamics. The measured prototype demonstrates an output power of 0.76mW at 292GHz and a tuning range of 4.5%. This chip presents the first high-power tunable source in sub-mm-wave frequencies. (ISSCC '12, PRL'12, JSSC'12).

Ultra-Fast Analog Signal Processing

We propose an ultra-fast signal processing scheme based on wave propagation in a passive network. In this technique the analog signal controls the interference pattern of the 2-dimenational lattice which is then detected and quantized. Based on this concept we design a 20GS/s quantizer which is the fastest single channel quantizer on silicon (MTT '10).

Delay-Line Based Data Conversion

There is a need for low-power scalable data converters for digital technologies. I use the concept of time-to-digital conversion and present a high-speed analog-to-digital convertor. Because the time-based structure avoids sensitive analog blocks it is highly suitable for digital technologies. The measured 4-bit ADC consumes only 2mW at 1.2GS/s. This mostly-digital design occupies less than 0.01mm² of active area. (JSSC '11, TCAS-II '09).