A 58 GHz Bandwidth, and less than 1.8% THD, Mach-Zehnder Driver, in 28 nm CMOS Technology

This work presents a linear Mach-Zenhder mod-ulator driver. The key features of this design are a distortion which goes with the inverse of the input amplitude and a wide bandwidth. The two things make the reported driver suitable for Coherent Optical Applications. The mainstream technology for these applications is BiCMOS, however, in this case, a 28 nm CMOS technology has been used, aiming for higher integration level and lower cost. The resulting Total Harmonic Distortion (THD) for 1.5 V peak-to-peak differential output swing is always below 1.8%, with a -3 dB bandwidth of 58 GHz. The complete transmitter provides gain ranging from 10 dB to 20 dB in a continuous way. The overall power consumption at 20 dB is 297 mW, with a single supply voltage of 2.4 V.