220 GHz wafer probe membrane tips and waveguide-to-coax transitions

We have developed two different styles of thin-film membrane tips for wafer probing to 220 GHz, and a membrane waveguide-to-coax transition. The new tips and waveguide-to-coax transitions are used in a family of ground-signal-ground wafer probes that offer improved measurement repeatability and calibration in the WR-10 through WR-5 waveguide bands. The new membrane waveguide-to-coax transition has been simulated using HFSS and built and measured in the lab. We have obtained good agreement between the measurements and simulations, and the new transition offers improved repeatability in measurements and calibration over our previous waveguide probe transition. Measured S21, S11 and crosstalk results for the new membrane waveguide-to-coax transition are also presented.