A GaAs distributed amplifier with an output voltage of 8.5Vpp for 40Gb/s modulators

In this paper, we report on a Distributed Amplifier (DA)with positive gain slope and 8.5 Vpp out put voltage swing at 20 GHz. This makes the amplifier suitable for driving LiNbO3 modulators. The amplifier consists of six cascode cells and is fabricated in a commercially available 150nm GaAs power pHEMT technology. Gain equals to 9.8 dB at low frequencies and rises up to 12.8 dB at 38GHz. This amplifier is then cascaded with a preamplifier. Losses at high frequencies due to cascading are compensated by the positive gain slope of the amplifier described here. The cascaded amplifiers exhibit again of 19.5 dB and a bandwidth of 38GHz with a flat frequency response of ±0.6dB up to 28 GHz