A 390 ps On-Wafer True-Time-Delay Line Developed by a Novel Micro-Coax Technology

A CMOS-compatible on-wafer true-time-delay (TTD) line for broadband microwave applications is demonstrated using a novel micro-coax technology. The insertion loss of the developed TTD line is less than 2.55 dB for a constant group delay of 390 ps from dc to 40 GHz, without control power or control voltage. To the best of our knowledge, the fabricated micro-coaxial TTD line provides the best figures-of-merit (FOM) value (0.00641 dB/ps at 40 GHz) among reported on-wafer TTD lines.