Analysis of the large-signal characteristics of InP/InGaAs-based optoelectronic preamplifiers

A model for soft breakdown effects in Inp/InGaAs-based single HBTs is developed. The effects of large-signal excitation on the operational characteristics of optoelectronic preamplifiers, such as the transducer and transimpedance gain of individual transistors, are addressed. These effects depend on optoelectronic integrated-circuit (OEIC) design and are associated with self-bias variations due to input power levels. Cascode designs are relatively immune to these effects, whereas basic coupled amplifiers are more sensitive (9-dB Ω vs. 3-dB Ω transimpedance reduction) for the same input power increase from −35 to −5 dBm. © 1996 John Wiley & Sons, Inc.