Yu-Ching Yeh received the B.S. and M.S. degrees in electrical engineering from National Taiwan University, Taipei, Taiwan, in 2009 and 2011, respectively. She is currently pursuing her Ph.D. degree at the University of California, Berkeley.
She worked on millimeter-wave wireless transceivers for her master's thesis, and current research interests focus on MEMS inertial sensor interface circuits.
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.