Duplexer Layout With Crossing Lines for Stop-Band Suppression

The patent applies dimensionality change by transitioning from a planar layout to a three-dimensional stacked configuration. The inductor is placed on a different layer than the series-arm resonator, with connection lines extending vertically through the substrate. This spatial separation in the vertical dimension reduces mutual inductance between the inductor and resonator, enabling high suppression characteristics even in a compact footprint.

The patent introduces an intermediary structure in the form of connection lines that route signals through the substrate between layers. These intermediary pathways allow the inductor and resonator to be electrically connected while maintaining physical separation in three-dimensional space, thereby reducing parasitic coupling while preserving electrical functionality.

The patent resolves the mutual inductance issue by separating the inductor and series-arm resonator into different vertical layers. The inductor resides on one layer while the resonator is on another layer, with their connection achieved through vertical vias and substrate traces. This dimensional separation minimizes magnetic coupling between the parallel-connected components, reducing harmful mutual inductance effects.

The patent applies local quality by optimizing the connection path between the inductor and resonator. The connection lines are routed through the substrate with specific geometric configurations that minimize loop area and proximity to other signal lines. This localized optimization of the connection structure reduces mutual inductance while maintaining the parallel connection topology.