An improved follower stage for the design of 40Gb/s wideband MMIC pHEMT modulator driver amplifiers

Within the use of GaAs pHEMT technology, the bandwidth performances of Cherry- Hooper driver amplifiers need to be improved. To fulfill these requirements, we propose an original driver circuit topology dedicated to 40 Gb/s optical communication systems. To validate this new architecture, an MMIC amplifier has been designed using the 0.2 μm GaAs E/D mode pHEMT process provided by the OMMIC foundry. The driver circuit achieves 10 dB of transducer gain from 100 kHz to 45 GHz and provides around 2 V_pp on 50 Ω load. Input return loss is less than -5 dB over the hand.