Design and Measurement Techniques for an 80 Gb/s 1-Tap Decision Feedback Equalizer A millimeter wave frequency mixed-signal design of a 1-tap half-rate look-ahead decision feedback equalizer for 80 Gb/s short-reach optical communication systems is presented. On-wafer tests are developed to determine the maximum operating bit rate of the equalizer. Results are also presented for intersymbol interference mitigation at 80 Gb/s for a 20 GHz bandwidth-limited channel. Further improvements on the architecture of the 80 Gb/s equalizer are discussed and used in the design and on-wafer measurement of a 110 Gb/s equalizer. The equalizers are designed in a 0.13 μm SiGe:C BiCMOS technology. The 80 and 110 Gb/s versions dissipate 4 and 5.75 W, respectively and occupy 2 and 2.56 mm 2 , respectively. Vol.49 No.2 452-470 452-470