Differential pulse regenerator driven by 1 Gbit/s p.c.m.-type signals from an avalanche photodiode

A hybrid-integrated pulse regenerator circuit, essentially employing an ultrabroadband 180° hybrid, step-recovery diodes and bipolar-transistor emitter followers, was operated by 1 Gibt/s signals delivered from an avalanche photodiode. A voltage gain of 20 dB could be measured on a single regenerator stage. RZ output pulses of halfwidths down to 100 ps were obtained, with the pulse shape being independent of the shape of the input pulses.