Non-Contact On-Wafer S-Parameter Measurements of Devices at Millimeter-Wave to Terahertz Frequencies

摘要

A broadband fully micromachined transition from rectangular waveguide to cavity-backed coplanar waveguide line for submillimeter-wave and terahertz application is presented. The cavity-backed coplanar waveguide line is a planar transmission line that is designed and optimized for minimum loss while providing 50 Ohm characteristic impedance. This line is shown to provide less than 0.12 dB/mm loss over the entire J-band. The transition from cavity-backed coplanar waveguide to a reduced-height waveguide is realized in three steps to achieve a broadband response with a topology amenable to silicon micromachining. A novel waveguide probe measurement setup is also introduced and utilized to evaluate the performance of the transitions.

主权项

1. A cavity-backed coplanar waveguide, comprising:
a ground plane member having a trench formed in a top surface thereof, the trench having a longitudinal axis and extending from one side of the ground plane member to an opposing side of the ground plane member; a metal layer disposed on and substantially covering the top surface of the ground plane member, including covering walls forming the trench; a dielectric membrane; and a microstrip formed on the dielectric membrane and configured to propagate a signal with a frequency in millimeter to terahertz range, wherein the dielectric membrane attaches to the top surface of the ground plane member, such that the longitudinal axis of the microstrip aligns with the longitudinal axis of the trench, and the microstrip is suspended in and spatially separated from walls of the trench.