Modeling of a Series-Shunt Bootstrapping Pre-amplifier Circuit for Free Space Optics

The signal level in an optical wireless receiver is weakest at the front end of the receiver due to the photodetector capacitance. Most of the papers have been previously reported successfully in bandwidth enhancement using bootstrapping technique. This paper introduces a series-shunt bootstrapping circuit which is boosted up the bandwidth to GHz. The modeling of the circuit exploits a series-shunt positive capacitive feedback. Feedback is applied to a buffered differential pair to obtain a bootstrap action. The result is only based on the modeling using MATLAB. Utilizing the dissimilar values of photodetector capacitance, the bandwidth does not alter to a great extent. Therefore, this circuit is suitable to implement in high noise environment especially in optical wireless link.