Solid-State and Nano Seminar
From Microwave to Millimeter-wave: The Design of Reconfigurable, High-Bandwidth CMOS Radios
The first part of this talk describes the application of phase-change vias to reconfigure CMOS integrated circuits. CMOS-compatible phase-change materials feature high contrasts in resistivity between the amorphous and crystalline states. While this property is being exploited in an emerging class of non-volatile memories, we are exploring its utility as a technological element to reconfigure integrated circuits, especially analog and RF circuits. The development of CMOS-compatible reconfigurable inductors, their application in a reconfigurable LC-VCO, as well as the underlying material choices and integration techniques are discussed. Other reconfigurable CMOS circuits including a low-offset comparator and a non-volatile look-up table are described. Characterization results from prototype circuits are presented to validate these concepts.
The second part of this talk addresses the design of low-power millimeter-wave radios in CMOS with extremely wide bandwidths. The mm-wave frequency bands hold enormous potential for multi-Gb/s communications as well as emerging imaging and ranging applications. The realization of this potential will be underpinned by the development of high-performance, power-efficient transceivers in nanoscale CMOS technologies. Two key challenges must be met towards achieving this goal. First, the mm-wave front-end circuits must be designed to operate over extremely wide bandwidths of several tens of GHz, both to exploit the large bandwidth availability, and also to provide sufficient margins to tolerate process, voltage and temperature variations that are increasingly problematic in nanoscale CMOS. Second, reducing power consumption in the front-end is imperative especially since phased-arrays are mandated in mm-wave transceivers.
This latter half of this talk describes our recent work towards achieving these goals. Transformer-based unilateralization techniques are introduced to enable the design of low-noise amplifiers that achieve over 10 GHz of bandwidth and can operate from a scalable power supply from the nominal voltage down to very low voltages. Low-voltage, ultra-wide bandwidth receivers for pulse-based mm-wave signals, and phased-array receivers, based on the aforementioned amplifiers, are presented. The design of transformer-based voltage-controlled oscillators with several 10's of GHz of tuning range is then described. Results from the characterization of several test circuits in 130 nm and 45 nm CMOS technologies are presented.
Jeyanandh Paramesh received the B.Tech, degree from IIT, Madras, the M.S degree from Oregon State University and the Ph.D degrees from the University of Washington, Seattle, all in Electrical Engineering. He is currently Assistant Professor of Electrical and Computer Engineering at Carnegie Mellon University. He has held product development positions with Analog Devices, where he designed high-performance data converters, and Motorola where he designed analog and RF integrated circuits for cellular transceivers. From 2002 to 2004, he was with the Communications Circuit Lab, Intel where he developed multi-antenna receivers, high-efficiency power amplifiers and high-speed data converters high data-rate wireless transceivers. His research interests include the design of RF and mixed-signal integrated circuits and systems for a wide variety of applications.