Research Interests: Sensor interface circuits, MEMS, signal processing, controls BIOGRAPHY was born in Temple, TX in 1986. Mitchell received his BS from Texas A&M University in 2008 and his MS from the University of California, Berkeley in 2010. He is continuing to pursue a PhD at Berkeley under the advisement of Professor Bernhard E. Boser.
His research interests include sensor interface circuits, MEMS inertial sensors, signal processing, and controls. He has previously worked on power electronics---specifically capacitive power transfer for contactless charging and LED lighting applications. He has completed internships at National Instruments in Austin, TX in 2007 and Intrinsity in Bee Cave, TX in 2008. FM Gyroscope [BPN608] We present a gyroscope operating mode that reduces bias errors and scale factor drift and allows whole angle read-out. The gyroscope proof mass orbits in a circle at its natural frequency. An outside observer rotating under the proof mass then perceives a frequency change. If the observer rotates in the same direction as the orbital spin, the perceived frequency decreases, and in the opposite direction, the frequency increases. The addition of a second gyroscope that spins in the opposite direction enables a differential measurement, reducing temperature sensitivity. The frequency difference is exactly the angular rate; thus, the phase difference is the whole angle. Rate bias errors due to mechanical quadrature and cross-axis damping are periodic on the current angle of the proof mass relative to the sensor frame and are hence averaged out over one cycle. A 3-theta dual ring gyroscope chip with integrated CMOS buffer electronics and an off-chip controller demonstrates the technique. |