Coplanar Waveguide Shielding Layer With Interdigitated Fingers

The patent moves the signal return path from the same plane (2D coplanar arrangement) to a different interconnect level (3D vertical arrangement). The ground plane is placed on a lower interconnect level beneath the signal line, allowing the signal return path to exist in a different dimensional plane. This eliminates the need for coplanar ground strips adjacent to the signal line, freeing up routing area while maintaining signal integrity through the vertical ground-signal-ground structure.

The lower interconnect level serves multiple functions: it provides the ground plane for signal return paths (electrical function) and simultaneously acts as a routing layer for additional signal interconnections (interconnection function). By making the lower interconnect level universal for both grounding and signaling purposes, the design maximizes the number of available interconnections while ensuring signal integrity through the ground plane.

The patent divides the interconnect structure into distinct functional segments: upper interconnect levels dedicated to signal routing and a lower interconnect level dedicated to grounding and additional signaling. This segmentation allows each layer to be optimized independently - the lower level provides a continuous ground plane that simplifies manufacturing compared to patterned ground strips, while upper levels handle signal routing. The modular segmentation reduces overall manufacturing complexity despite supporting multiple devices.

By transitioning from 2D coplanar interconnection to 3D multi-level interconnection, the patent enables increased device interconnection capability without proportionally increasing routing area consumption. The vertical stacking of interconnect levels allows signals to route above and below ground planes, effectively multiplying the interconnection capacity within the same footprint while maintaining manageable manufacturing complexity through standardized layer structures.