GaInP/GaAs HBT broadband monolithic transimpedance amplifiers and their high frequency small and large signal characteristics

Monolithic broadband transimpedance amplifiers were developed using GaInP/GaAs single HBTs. The HBTs showed a cut off frequency (f/sub T/) of 60 GHz and maximum oscillation frequency (f/sub max/) of 100 GHz. The fabricated amplifiers had a maximum bandwidth of 19 GHz and an associated transimpedance gain of 47 dB/spl Omega/. The large signal characteristics of two transimpedance amplifier designs with similar gain were also investigated and showed that the cascode approach is much less sensitive to input power level.