A metamorphic GaAs HEMT distributed amplifier with 50 GHz bandwidth and low noise for 40 Gbits/s optical receivers

An eight stage distributed amplifier with 12.5 dB /spl plusmn/ 0.45 dB gain and 50 GHz bandwidth has been demonstrated in a commercially available 0.1 /spl mu/m metamorphic GaAs HEMT (MHEMT) technology. The amplifier has a minimum noise figure lower than 2.5 dB in the bandwidth. The group delay variation from 9 to 40 GHz is /spl plusmn/ 7.5 ps and circuit consumption is 0.4 W. Such amplifier has been packaged with a high responsivity photodiode into a fiber pig-tailed module. Eye diagrams measurements demonstrate the successful high-speed operation of the photoreceiver.