Gain flattening technique for optical wireless front-end receiver considering various large window photodetectors

A novel gain flattening technique for an optical wireless front-end receiver structure involving a bootstrap transimpedance amplifier (BTA) integrated with a MEMS variable feedback capacitor has been demonstrated. The MEMS varicap replaces a fixed capacitance as the feedback element in the front end system to optimize the performance of the BTA in terms of its frequency response. The implementation of the MEMS device with a BTA optical front-end receiver was verified using CoventorWare ARCHITECT. The simulation results showed that the approach can significantly flatten the peaking gain by up to 14 dB, when considering a system with various photodetector capacitances, ranging in value from 100 pF to 1 nF.