A DC-12 GHz monolithic GaAsFET distributed amplifier

A monolithic balanced traveling-wave amplifier stage using GaAs MESFET's is demonstrated. This amplifier achieves 7-9-dB gain with about 40-ps risetime and a -3-dB bandwidth of 12 GHz, on a 0.91 × 0.97-mm die. Its gain versus frequency is very flat, and |S11|, |S12|, and |S22| are less than 0.2 from 0-18 GHz. S-parameter uniformity and yield data are measured on-wafer with a special hybrid wafer probe.