Bandwidth Analysis of Bootstrap Transimpedance Amplifier for Optical Free Space Receiver

Free Space Optic (FSO) or optical wireless link operates in high noise environments. On the other hand, theperformance is subjected to several atmospheric factors like environmental temperature, fog, smoke, haze and rain. Signalto-noise ratio (SNR) can vary radically with the distance and ambient noise. A good sensitivity and a broad bandwidth willhabitually use a small photodetection area where the aperture is small. However, FSO optical receiver requires a largeaperture and accordingly, to have a large collection area, which possibly will be achieved by using a large area photodetectorand large filter. Consequently, large area photodetector produces a high input capacitance that will be reduced thebandwidth. Hence, techniques to reduce the effective detector capacitance are required in order to achieve a low noise aswell as wide bandwidth design. In this paper, modeling and analysis of the series and shunt with floating source: and seriesshuntbootstrap transimpedance amplifier (BTA) of front-end receiver for input capacitance reduction will be presented. Theresult shows that the technique improved the conventional transimpedance amplifier (TIA) bandwidth up to 1000 times withan effective capacitance reduction technique for optical wireless detector.