Van der Spiegel, Jan
Electrical and Electronics
Professor of Electrical Science and Engineering
Research Interests Vision Sensors: We are studying novel current-mode image sensors with analog spatial processing and a new pixel array design, in which several techniques are combined to improve the quality of the images. Included in the design is a new addressing scheme that allows a group of pixels to share the same readout circuitry, therefore reducing the pixel size and increasing the resolution. The new design has removed the in-pixel accessing switches, and uses velocity saturated operation in order to increase the readout linearity. We are also integrating a successive approximation ADC on the imager. The ADC is natively current mode, and is designed to interface directly with the current mode pixels without the need for sample-and-hold circuits or current-to-voltage converters. Sensor for Polarization Imaging: We are also developing a focal plane imaging sensor capable of real time extraction of polarization information. The imaging system consists of a photo array of linear current mode active pixel sensors and analog processing circuitry for computation of the Stokes parameters. A dual-tier thin film micro-polarizer array has been deposited on the imager. A commercially available thin film polarizer is used to create an array of micro-polarizers. The thin film polarizer consists of an iodine-doped Polyvinyl Alcohol (PVA) layer which is patterned and etched using RIE. The measured extinction ratios of the filters are 1000 and 100 for the blue/green and red spectrum, respectively. Mixed mode Integrated Circuits for Data Acquisition Systems and Communications: We are currently exploring different architectures and algorithms to realize high performance analog-to-digital converters. One project deals background calibration schemes to correct for any residual non-idealities (linear and non-linear) in pipe-lined analog-to-digital converters. We are also developing CMOS circuits for RF communications using AlN Contour-Mode Piezoelectric Resonators in collaboration with Prof. G. Lucca’s group.