Tunable and Highly Power Efficient Traveling Wave Amplifier in SiGe BiCMOS for Optical Modulators

In this paper, a highly efficient linear traveling wave amplifier enabling beyond 100GBaud optical data communication is presented, utilizing the “quasi-off” states approach to decrease the overall power consumption maintaining a high bandwidth. The circuit is designed in a SiGe BiCMOS technology featuring 15.3 dB small signal gain within a 87.4 GHz 3 dB bandwidth, while the 1dB output compression point reaches 13.3 dBm for a power efficiency of 4.1%. Time domain measurements demonstrate a non-return-to-zero transmission data rate of 120 Gb/s. The amplifier consumes an overall DC power of 499mW at maximum gain state, and the “quasi-off” states approach enables a power saving up to 50% without deteriorating the bandwidth.