Performance characterization of Heterojunction Bipolar Transistor as an optoelectronic mixer

Abstract

This paper explains the development of physical model Heterojunction Bipolar Transistor (HBT) andcharacterizes its performance as an optoelectronic mixer (OEM). HBT has been identified as a suitabledevice to be implemented in optoelectronic mixers by simultaneously photodetecting an intensitymodulated laser beam at 1550nm and frequency translating the detected signal to a higher or lowerfrequency which can provide high mixing efficiency and required condition for an oscillator. The HBTOEM was designed, modeled and simulated by using APSYS Crosslight software. Data from thesimulation such as the gummel plot, energy band diagram and other characteristics have been generatedand analyzed. The device was analyzed considering 1550nm wavelength with up to 30GHz modulatingsignal frequency. Hence, the designed HBT is found to be possible for the implementation of thebroadband RoF system as it can perform the photodetection, amplification and frequency conversionsimultaneously as required at RoF remote antenna unit.