A HSPICE equivalent-circuit model for analyzing the frequency response of segmented traveling wave electroabsorption modulators (STEAM) is presented. The model is based on non-physical model for lossy transmission line. The analysis indicates that STEAM can achieve much wider bandwidth than the lumped electroabsorption modulator (LEAM) and TWEAM counterparts, with a small penalty in E/O conversion gain if low loss passive optical waveguide is available.