48-GHz digital IC's and 85-GHz baseband amplifiers using transferred-substrate HBT's

Using substrate transfer processes, we have fabricated heterojunction bipol ar transistors with submicrometer emitter-base and collector-base junctions , minimizing RC parasitics and increasing f(max) to 500 GHz, The process al so provides a microstrip wiring environment on a low-epsilon(r) dielectric substrate, First design iterations of emitter-coupled-logic master-slave fl ip-flops exhibit 48 GHz maximum clock frequency when connected as static fr equency dividers. Baseband amplifiers have been demonstrated with bandwidth s up to 85 GHz.