A comparative study of on-wafer and waveguide module S-parameter measurements at D-band frequencies
In this paper, we present a comparative study of S-parameter measurements of electronic components on planar substrates performed with a waveguide module and in a conventional on-wafer probing environment. Measurements were conducted at three well-established measurement laboratories for the investigation of reproducibility at frequencies from 110 to 170 GHz. For the comparison, we fabricated waveguide modules for six passive structures, including devices under test (DUTs). Four of these structures are related to using a second tier calibration to achieve the same reference planes for the waveguide module measurements as used for the on-wafer probing measurements. Additionally, we processed three complete on-wafer calibration sets, including DUTs, equipped with different probe-to-pad interfaces. In this comparison, the DUT measurement from the waveguide module acts as a reference standard, with reduced crosstalk behavior in comparison to the on-wafer measurement. With the waveguide reference, we are able to assess the ability of two techniques to compensate for crosstalk and higher order modes influencing the on-wafer S-parameter measurements. On the one hand, we use a shielded probe-to-pad transition and on the other hand, we use an algorithm-based crosstalk correction scheme. To the best of our knowledge, this is the first time that such a comparison has been undertaken, comparing well-established waveguide calibrations with an equivalent on-wafer calibration.