An experimental 20 Gbit/s decision circuit IC based on AlGaAs/GaAs HBTs has been implemented, which features a differential input sensitivity of 80 mV peak to peak and a phase margin of 292° at the SONET STS-192 rate of 9.95 Gbit/s. The IC nominally dissipates 870 mW of power, but may be operated up to 10 Gbit/s with a power dissipation of 450 mW. The circuit was fabricated in a high current gain baseline HBT technology, an d occupies an area of 1.15×1 mm2.