Double-mode surface-acoustic-wave (DMS) filter having a modulated interdigital transducer

An apparatus comprising:

• a double-mode surface-acoustic-wave filter comprising:
• at least one interdigital transducer comprising a first busbar, a second busbar, and multiple fingers extending from the first busbar toward the second busbar, the multiple fingers comprising:
• a first set of fingers having a first spatial property;
• and
• a second set of fingers having a second spatial property different from the first spatial property, the second spatial property comprising at least two fingers of the second set of fingers positioned adjacent to each other, wherein the at least one interdigital transducer comprising a first interdigital transducer, wherein
• the double-mode surface-acoustic-wave filter further comprises:
• a second interdigital transducer;
• a third interdigital transducer;
• a first reflector;
• and
• a second reflector, wherein the first interdigital transducer, the second interdigital transducer, and the third interdigital transducer are disposed between the first reflector and the second reflector, wherein the second interdigital transducer comprises a third busbar, a fourth busbar, and multiple other fingers extending from the third busbar toward the fourth busbar, the multiple other fingers comprising:
• a third set of fingers having a third spatial property;
• and
• a fourth set of fingers having a fourth spatial property different from the third spatial property, the fourth spatial property comprising at least two fingers of the fourth set of fingers positioned adjacent to each other, and wherein:
• the second set of fingers comprises a first quantity of fingers per cell of multiple cells of the first interdigital transducer;
• and
• the fourth set of fingers comprises a second quantity of fingers per cell of multiple cells of the second interdigital transducer, the first quantity of fingers per cell different from the second quantity of fingers per cell.

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 extending from a first busbar of the at least one interdigital transducer toward a second busbar of the at least one interdigital transducer, the first set of fingers having a first spatial 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 extending from the first busbar toward the second busbar, the second set of fingers having a second spatial property different from the first spatial property, the second spatial property comprising at least two fingers of the second set of fingers positioned adjacent to each other;
• providing a third set of fingers of the at least one interdigital transducer of the double-mode surface-acoustic-wave filter, the third set of fingers extending from the second busbar toward the first busbar, the third set of fingers having the first spatial property;
• and
• providing a fourth set of fingers of the at least one interdigital transducer of the double-mode surface-acoustic-wave filter, the fourth set of fingers extending from the second busbar toward the first busbar, the fourth set of fingers having a third spatial property, the third spatial property comprising at least two fingers of the fourth set of fingers that are separated by a gap sufficient to permit the at least two fingers of the second set of fingers that are positioned adjacent to each other to be positioned between the at least two fingers of the fourth set of fingers.

An apparatus comprising:

• a double-mode surface-acoustic-wave filter comprising at least a first interdigital transducer and a second interdigital transducer, each of the first interdigital transducer and the second interdigital transducer comprising:
• a first region comprising multiple fingers arranged to alternate fingers from different busbars, the multiple fingers of the first region having a first pitch;
• and
• a second region comprising multiple other fingers arranged to include at least two adjacent fingers extending from a same busbar, the multiple other fingers of the second region having a second pitch that is smaller than the first pitch, wherein the second region of the first interdigital transducer is adjacent to the second region of the second interdigital transducer.