Design of low-noise fiber-optic receiver amplifiers using J-FET´s

Design techniques for photodetector amplifiers employing J-FET´s are investigated. A simple J-FET noise model is used to derive expressions for amplifier noise density and frequency response. The amplifier types discussed include single and multiple stage amplifiers. A total of six amplifier configurations are compared on the basis of their noise performance, dynamic range, and the frequency response. Some experimental results are presented to verify the calculations.