US 12,500,569 B1
Longitudinally coupled resonator type surface acoustic wave filter and elastic wave filter
Jianli Jiang, Jiaxing (CN); Yangyang Ma, Jiaxing (CN); Dan Liang, Jiaxing (CN); and Qingsong Liao, Jiaxing (CN)
Assigned to Tiantong Ruihong Technology Co., Ltd., (CN)
Filed by Tiantong Ruihong Technology Co., Ltd., Jiaxing (CN)
Filed on Mar. 25, 2025, as Appl. No. 19/090,319.
Claims priority of application No. 202410773644.8 (CN), filed on Jun. 17, 2024.
Int. Cl. H03H 9/02 (2006.01); H03H 9/64 (2006.01)
CPC H03H 9/02952 (2013.01) [H03H 9/02637 (2013.01); H03H 9/02992 (2013.01); H03H 9/6433 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A longitudinally coupled resonator type surface acoustic wave filter, comprising a signal terminal, a ground terminal, and an interdigital transducer group, wherein the interdigital transducer group comprises at least a first interdigital transducer and a second interdigital transducer arranged along a first direction; the first interdigital transducer comprises a first busbar, and the second interdigital transducer comprises a second busbar; and
the first busbar is electrically connected to the signal terminal via a first signal line, and the second busbar is electrically connected to the ground terminal via a first ground line; and the first ground line and the first signal line do not overlap,
wherein the first busbar and the second busbar are arranged along the first direction;
the first interdigital transducer further comprises a third busbar, wherein the third busbar and the first busbar are arranged along a second direction, the third busbar is electrically connected to the ground terminal via a second ground line, and the second direction intersects with the first direction; and
the longitudinally coupled resonator type surface acoustic wave filter further comprises at least one electrode finger, wherein the at least one electrode finger extends along the second direction, one end of the at least one electrode finger is electrically connected to the second busbar, and the other end of the at least one electrode finger is electrically connected to the third busbar, wherein the second interdigital transducer further comprises a fourth busbar, and the fourth busbar is arranged with the second busbar along the second direction, and is arranged with the third busbar along the first direction;
the signal terminal is a single-input single-output signal terminal comprising only a single first signal terminal and a single second signal terminal, wherein the first busbar is electrically connected to the first signal terminal via the first signal line, and the fourth busbar is electrically connected to the second signal terminal via a second signal line; and
along the first direction, a gap is arranged between the first busbar and the second busbar, and a gap is arranged between the third busbar and the fourth busbar; and the first signal terminal is an input signal terminal, and the second signal terminal is an output signal terminal; or, the first signal terminal is an output signal terminal, and the second signal terminal is an input signal terminal, wherein the ground terminal is located only on a side of the longitudinally coupled resonator type surface acoustic wave filter close to the first signal terminal.