Improved AlInAs/GaInAs HBTs for high-speed circuits

This paper describes the demonstration of CML ring-oscillators and static frequency divider circuits implemented with AlInAs/GalnAs heterojunction bipolar transistors (HBTs) lattice matched to InP substrates. A cutoff frequency (fT) and a maximum frequency of oscillation of 90 GHz and 70 GHz, respectively, have been achieved with a 2x5-?m2 emitter. The ring oscillators demonstrated a 15.8 ps gate delay. The divider circuits were clocked at 24.8 GHz.