A 128 Gb/s 7-Tap FIR Filter in 130 nm SiGe BiCMOS for High-Speed Channel Equalization

In this letter, a fully analog differential 7-tap 128 Gb/s finite impulse response (FIR) filter using IHP’s 130 nm SG13G2 SiGe:C BiCMOS process is presented. The design includes microstrip transmission line (TL) delay structures for introducing 3 ps tap delay, which corresponds to a third-bit period at 112 Gb/s. Detailed measurements show that the filter is capable of eye diagram improvements up to 128 Gb/s while consuming 693 mW, demonstrating its suitability for new generation 400 Gb/s communication channels. To the best of the authors’ knowledge, this is the fastest NRZ equalization by a fully analog FIR filter, to be found in the literature.