Young Kwark, Research Staff Member, IBM Watson Research
Christian Schuster, Research Staff Member, IBM Watson Research
Lei Shan, Research Staff Member, IBM Watson Research
Christian Baks, Staff Engineer, IBM Watson Research
Jean Trewhella, Research Staff Member, IBM Watson Research

Characterization of printed circuit board structures such as embedded transmission lines and vias has relied on coaxial connectors or high frequency microwave probes to provide interfaces to test equipment. Both approaches require vias to access internal layers which can severely distort high frequency behavior of the structure being measured. This paper describes a different access technique that allows a clean launch directly from microwave probes into a stripline structure. The quality of the launch is sufficient to permit characterization of small structures to frequencies of 40GHz. Actual S-parameter data obtained with this technique shows good agreement with 3D EM simulations.