Up to 80-Gbit/s operations of 1:4 demultiplexer IC with InP HBTs

We report up to 80-Gbit/s operations of a 1:4 demultiplexer (DMX) IC with InP HBTs of f/sub T/=292 GHz, f/sub max/=308 GHz. The circuit features are 1) the multiphase clock (MPC) architecture to suppress the increase of the power consumption, and 2) the high collector current density of 5.0 mA//spl mu/m/sup 2/ for the fastest circuit blocks. To measure the IC at over 50 Gbit/s where available data pulse pattern generators (PPGs) are few, we constructed two-types of data PPGs, which were a purely electrical PPG (E-PPG) and an optoelectronic PPG (OE-PPG). With these technologies, we successfully confirmed the operations up to 80 Gbit/s for the 1:4 DMX IC.