Analog 2:1 Multiplexer with over 110 GHz Bandwidth in SiGe BiCMOS Technology

We report on a 2:1 analog multiplexer (AMUX) circuit in 130-nm SiGe BiCMOS technology. The technology offers HBTs with peak f
T
of 470 GHz and f
max
of 650 GHz. S-parameter measurements of the AMUX IC show a significant leap in bandwidth compared to the circuit in the previous technology generation. The linear signal path offers a 3-dB-bandwith beyond 110 GHz, while the limiting clock path has 85 GHz 3-dB-bandwidth. With this circuit two digital-to-analog converters (DACs) can be time-interleaved, to generate multi-level signals far beyond 100 GBaud with both high bandwidth and linearity.