Fully integrated distributed amplifier design on InP HBT technology for optoelectronics application

The bandwidth required by the amplifiers used for the 40 Gbits/sec photonic communication systems are linked to the actual data rate required and to the modulation used: over 50 GHz bandwidth may be required in certain cases. This paper presents the design of a completely integrated distributed amplifier for high data rate type of applications. Thanks to the use a special DC bias circuit, the amplifier just requires one negative voltage (-5 V) supply. As no decoupling capacitor is used to bias the active cells, the amplifier has no low cutoff frequency. The amplifier gain is 15 dB and its 3 dB cutoff frequency bandwidth 65 GHz, which gives an equivalent gain bandwidth product of 390 GHz. This is at the state of the art for the technology used. The simulation of the electromagnetic extraction of the layout is compared to the measurements results from DC to 50 GHz.