| 摘要 |
A method and apparatus for a ladder filter (300, 400) incorporating same. The filter (100, 300, 400, 1803, 1807, 1815, 1823, 1829) includes a substrate and a first series resonator (305, 403) disposed on the substrate and electrically coupled in series between the first electrical port (301, 401) and a first node. The first series resonator (305, 403) includes a first series acoustic reflector (303), a first series gap, a first series transducer (304, 403), a second series gap and a second series acoustic reflector (306) collectively disposed in an in-line configuration along a principal axis (8, 9) of the substrate. The filter (300, 400) also includes a first shunt resonator (310, 404) disposed on the substrate and electrically coupled in shunt between the first node and ground. The first shunt transducer (312) and the first series transducer (304) have different periodicities not equal to periodicities of the first (303) and second series acoustic reflectors (306) and the first (311) and second (313) shunt acoustic reflectors. <IMAGE> |
