Mass-Loaded IDT Electrode Layout for Unwanted Wave Suppression

The patent applies local quality by making the mass-added films have different widths at different positions along the electrode fingers. The films are wider at the proximal end and narrower at the distal end, creating a gradient mass distribution that selectively suppresses unwanted waves while maintaining the desired thickness shear mode bulk wave generation. This non-uniform mass distribution targets specific wave modes locally rather than applying a uniform approach across the entire structure.

The patent changes the mass parameter by adding films with varying widths to the electrode fingers. By controlling the width of mass-added films along the electrode finger length, the patent modifies the mass distribution parameter to suppress plate wave and harmonic wave generation. The continuous variation in film width creates a gradient that changes the local resonant frequencies, effectively pushing unwanted modes out of the operating bandwidth.

The patent merges the mass-added films with the electrode fingers by forming them as an integrated structure. The films are deposited or formed directly on the electrode fingers during the same fabrication process, combining two functional elements (electrode and mass loading) into a single integrated component. This reduces the number of separate parts and simplifies assembly while achieving the desired wave suppression effect.

The patent controls the complexity by precisely defining the geometric parameters of the mass-added films. The films have a specific width profile (wider at proximal end, narrower at distal end) and are positioned at specific locations on the electrode fingers. By optimizing these parameters, the patent achieves effective unwanted wave suppression with a relatively simple film structure that can be fabricated using standard thin-film deposition techniques.