Surface acoustic wave electroacoustic device using gap grating for reduced transversal modes

A method for forming an electroacoustic device, comprising:

• forming a layer of a piezoelectric material;
• and
• forming an electrode structure on or above the piezoelectric material, forming the electrode structure comprising:
• forming a first busbar and a second busbar;
• forming a first conductive structure connected to the first busbar and a second conductive structure connected to the second busbar, the first conductive structure and the second conductive structure disposed between the first busbar and the second busbar, the first conductive structure and the second conductive structure each formed from a plurality of conductive segments separated from each other and extending towards one of the first busbar or the second busbar;
• and
• forming electrode fingers arranged in an interdigitated manner and each connected to either the first conductive structure or the second conductive structure, the electrode fingers formed to have a pitch that is different than a pitch of the plurality of conductive segments of the first conductive structure and the second conductive structure;
• wherein a dimension of the first conductive structure in a direction in which the plurality of conductive segments extend is between 1.25 times and 4 times a wavelength for an operating frequency of the electroacoustic device.

An electroacoustic device, comprising:

• a piezoelectric material;
• and
• an electrode structure, comprising:
• a first busbar and a second busbar;
• a first conductive structure connected to the first busbar and a second conductive structure connected to the second busbar, the first conductive structure and the second conductive structure disposed between the first busbar and the second busbar, the first conductive structure and the second conductive structure each comprising a plurality of conductive segments separated from each other and extending towards one of the first busbar or the second busbar;
• and
• electrode fingers arranged in an interdigitated manner and each connected to either the first conductive structure or the second conductive structure, the electrode fingers having a pitch that is different than a pitch of the plurality of conductive segments, wherein the electrode fingers have a central region with a first trap region located on a boundary of the central region;
• wherein a dimension of the first trap region in a direction in which the electrode fingers extend is between one-half of the pitch of the electrode fingers and twice the pitch of the electrode fingers.