====== Alex_Guo ======

{{wiki:Yang Guo.JPG?200|Yang Guo.JPG}}<br> 

BSEE, Tsinghua University, 1996 <br> MSEE, University of Toledo, 1998 <br> Ph.D, Stanford University, 2014 <br> 

**Research**: //Densely Integrated Interface Circuits for Structural Health Monitoring// 

A promising approach in aerospace Structural Health Monitoring (SHM) is embedding a large-scale piezoelectric transducer array into the aircrafts’ structure to detect defects during service. Building the interface electronics of the large-scale array in IC form is essential to the embeddability of the whole system. The challenge is driving the piezoelectric transducer with a precise waveform at high voltages and ultrasonic frequencies.&nbsp;We propose a solution using pulse width modulation (PWM), in which the tone-burst signal is rendered by a series of precisely timed pulses. A calibration technique is introduced to achieve sub-nanosecond timing accuracy and -40.5 dB signal distortion. 

We fabricated a four-channel, ±36 V, 780 kHz piezo driver chip in 0.25 micron BCD (Bipolar-CMOS-DMOS) technology. The IC was successfully evaluated within an application test bed.<br> 

We are working on the next generation design, which is an eight-channel SHM IC with both the driving and receiving circuits in each channel.

{{wiki:Alex SHM collage.jpg}}<br> <br> 

<br> 

**Email**: [[mailto:alexguo@stanford.edu|alexguo AT stanford DOT edu]]<br>