Design of Process and Environment Adaptive Ultra-Low Power Wireless Circuits and Systems

The explosive growth of portable battery operated devices has mandated design of low power circuits and systems to prolong battery life. These devices fabricated in modern nanoscale CMOS technologies suffer from severe process variation due to the reduced controllability of the fabrication process, causing yield loss. This calls for integrated low power and process tolerant design techniques, or design of systems that can adapt to its process and environment to maintain its performance while minimizing power consumption.;Currently, most of the wireless circuits are designed to meet minimum quality-of-service requirements under worst-case wireless link conditions (interference, noise, multi-path effects), leading to high power consumption when the channel is better than worst-case. In this research, we develop a multi-dimensional adaptation approach for wireless transmitters and receivers that optimally trades-off power vs. performance across temporally changing operating conditions by concurrently tuning control parameters in the RF front end to lower power consumption. Tunable circuits (e.g. LNA) with built-in tuning knobs providing independent controllability of important specifications allow optimal adaptation. Process sensing using intelligent test and calibration facilitates yield improvement and the design of process tolerant environment adaptive systems.