Abstract

A broadband amplifier for high-bitrate transmission is presented, using a standard GaAs-HBT process with fT and fmax of 36 and 170 GHz, respectively, at the operating bias point. The design takes optimum advantage of the available technology, reaching 75% of fT, a record value for GaAs HBT. Well-opened output eye diagrams at 20 and 40 Gbps are obtained with 1.4 Vpp and 1.2 Vpp, respectively, as well as a 4 Vpp output swing at 20 Gbps for 1.7 Vpp input signal. The measured eye diagrams demonstrate the potential for applications as 40 Gbps pre-amplifier and 20 Gbps modulator drivers.