DESIGN CONSIDERATIONS FOR WIDE-BAND P-I-N HBT MONOLITHIC TRANSIMPEDANCE OPTICAL RECEIVERS

A comprehensive circuit and device model has been developed for the de sign of wide-band transimpedance optical receivers using heterojunctio n bipolar transistors (HBT's). Based on this model, we determine the d evice and circuit design that gives the highest combination of bandwid th, sensitivity, and stability. For optoelectronic integration, it is convenient to use the collector-base junction of the HBT device struct ure to fabricate the p-i-n detector. A resulting transistor transit-ti me effect is shown to cause shunt peaking in the closed-loop response or, at worst, instability. It is shown that the photodiode stray capac itance is not a major source of sensitivity degradation in flip-chip t ransimpedance receivers. Optimum device structures are determined for InP- and GaAs-based HBT receivers with fine-line as well as relaxed ge ometries.