Double-mode surface-acoustic-wave (DMS) filter having a transition region with a partly uniform geometric property

An apparatus comprising:

• a double-mode surface-acoustic-wave filter comprising at least two adjacent interdigital transducers, the at least two adjacent interdigital transducers comprising a first set of fingers having a geometric property and a second set of fingers including a first subset of fingers and a second subset of fingers, the second set of fingers being positioned within a transition region of the double-mode surface-acoustic-wave filter,
• wherein each finger of the first set of fingers and the second set of fingers has a uniform width with respect to other fingers of the first set of fingers and the second set of fingers, and
• wherein a profile of a geometric property across the second set of fingers has a trapezoidal shape based on a geometric property across a second subset of the second set of fingers incrementally increasing or decreasing between a value of the geometric property across the first subset of fingers of the second set of fingers and a value of the geometric property across the first set of fingers.

A method of manufacturing a double-mode surface-acoustic-wave filter, the method comprising:

• providing a first set of fingers of at least one interdigital transducer of the double-mode surface-acoustic-wave filter, the first set of fingers having a geometric property;
• and
• providing a second set of fingers of the at least one interdigital transducer of the double-mode surface-acoustic-wave filter, the second set of fingers positioned adjacent to the first set of fingers and associated with an outer edge of the at least one interdigital transducer, wherein each finger of the first set of fingers and the second set of fingers has a uniform width with respect to other fingers of the first set of fingers and the second set of fingers, the geometric property across a first subset of the second set of fingers being substantially uniform, a value of the geometric property across the first subset of the second set of fingers being different than a value of the geometric property across the first set of fingers, wherein the geometric property across a second subset of the second set of fingers incrementally increases or decreases between the value of the geometric property across the first subset of the second set of fingers and the value of the geometric property across the first set of fingers.