A hybrid approach is proposed to signal integrity analysis of trace and vias in plate pair with an infinitely large dimension. By using the domain decomposition method, trace domain and via domain are divided from the plate domain. Each individual domain of via and trace structure is modeled by the 3-D full-wave tool HFSS as a multimode network composed of TEM mode waveguide ports at top/bottom antipad interfaces and vertical lumped ports on the segmentation interfaces.
The plate domain is dominated by TMZ0 modes and network parameters are solved by boundary integral method. Connection of network of each domain enforces the field continuity conditions along the segmentation interfaces and yields the final S parameter of trace and via as well as trace/via to trace/via coupling. Once the via pattern and trace routing are determined, the coupling can be efficiently modeled by the proposed hybrid approach and the layouts of via structures and trace routing in a plate pair are efficiently optimized.