Prof. David Wentzloff's group focuses on energy-efficient circuits for wireless communication. It has developed all-digital radios that are synthesized from standard digital libraries, leveraging the precise timing of CMOS, and benefiting from automated layout and technology scaling. The group also developed radios that enable wireless networks of vanishingly-small sensors. One approach to address the severely limited volume and energy capacity constraints is to eliminate the need for a crystal reference. The group has demonstrated radios that derive an accurate clock reference from the standing wave on a patch antenna, and that harvest a clock reference from the GSM cellular network. It has also developed hardware to measure and characterize wireless channel-models in real-time for body sensor networks. These models target cognitive body sensor network radios with communication policies that can adapt to body movements. This enables opportunistic communication, and ultimately results in lower total energy consumption.
Prof. Michael Flynn's group is investigating flexible and adaptable energy-efficient transceivers. New digital dominant techniques that exploit the speed of nanometer CMOS processes are being researched. As an example, a digital dominant PLL scheme was demonstrated with GSMK and OQPSK modulation. An adaptable receiver can reliably receive 900MHz and 2.4GHz band 802.15.4 and WiFi. Very-high-frequency transceivers are also being investigated.