Emerging Electromagnetic-Acoustic Sensors for Automotive and Healthcare Applications
Emerging Electromagnetic-Acoustic technique is to combine the merits of traditional electromagnetic sensing technique (e.g. Radar and Lidar) with acoustic imaging (e.g. microphone and ultrasound), and go beyond. In this lecture, we would present three topics: (1) Low power phase arrayed radar chip for Synthetic Aperture Radar (SAR) imaging, (2) Photoacoustics sensing and imaging systems, and (3) Thermoacoustics sensing systems. On the phase array radar transceiver, the design challenge is to generate and transmit multi-phased wideband chirp signal and to do stretch processing based high resolution beamforming. The detailed circuits and systems to implement the radar sensor will be introduced. Photoacoustics sensors transmit focused laser light to deeply penetrate to the tissues/blood vessels, inducing high frequency ultrasound signals, and then high- resolution acoustic imaging can be formed. To miniaturize the whole sensor and achieve high sensitivity, the fibre coupled pulsed lasers, beamforming ultrasound transducers, and low power low noise signal acquisition circuits are designed and implemented. Furthermore, there appears increasing interests to use microwave induced thermoacoustic and/or magenetoacosutic signals for NDT applications. We will briefly discuss some coil-based EM transmitter for wireless power transfer and EMAT based non-contact sensing.