Short-Open Calibration Technique for Field Theory-Based Parametric Extraction of Planar Discontinuities with Nonuniform Feed Lines

In this work, a short-open calibration technique is extended for field theory-based parametric extraction of planar discontinuities with nonuniform feed lines in the platform of full-wave method-of-moments. As a planar discontinuity is analyzed with respect to the planes of impressed sources, each individual nonuniform feed line is modeled as a general error box relying on the perfect short-and open-circuit standards. By calibrating out all the error boxes associated with all the nonuniform feed lines, the core discontinuity section can be deembedded based on the cascaded network theorem. Since each individual feed line is modeled as a unified two-port circuit instead of a transmission line section, the presented technique provides an advantageous feature in deembedding various planar circuits that may be fed by nonuniform lines, as met in the high-density and high-integrated circuits. After theoretical description is made on the deembedding procedure, a microstrip-line slit discontinuity with varied feed lines is numerically characterized. Extracted equivalent circuit parameters are at first confirmed by the Sonnet em simulator in the uniform case and then substantially demonstrated in various nonuniform cases.