Low-Loss DC-100 GHz Suspended Microstrip Lines on Micromachined SiGe BiCMOS BEOL Technology

A new class of low-loss transmission lines implemented on the BEOL of a 0.25 μm SiGe BiCMOS technology is presented and experimentally demonstrated up to 100 GHz. The approach consists in a monolithic microstrip line suspended on an air cavity by means of two novel structural solutions. With respect to a conventional transmission line in the same technology, an attenuation loss reduction of up to 3 dB/cm has been reached at 60 GHz.