US 12,231,112 B2
Bridge-type filters
Edgar Schmidhammer, Stein an der Traun (DE); Marc Esquius Morote, Munich (DE); and Juha Sakari Ella, Salo (FI)
Assigned to RF360 Singapore Pte. Ltd., Singapore (SG)
Filed by RF360 EUROPE GMBH, Munich (DE)
Filed on Sep. 22, 2022, as Appl. No. 17/934,414.
Claims priority of provisional application 63/269,441, filed on Mar. 16, 2022.
Prior Publication US 2023/0299741 A1, Sep. 21, 2023
Int. Cl. H03H 9/54 (2006.01); G06F 3/14 (2006.01); H03H 9/00 (2006.01); H03H 9/205 (2006.01); H03H 9/60 (2006.01); H03H 9/70 (2006.01); H04B 1/52 (2015.01); H04B 1/71 (2011.01)
CPC H03H 9/542 (2013.01) [G06F 3/14 (2013.01); H03H 9/205 (2013.01); H03H 9/60 (2013.01); H03H 9/70 (2013.01)] 46 Claims
OG exemplary drawing
 
1. An apparatus comprising:
a filter circuit comprising:
a first port that is single-ended;
a second port that is single-ended;
a transformer comprising a first terminal, a second terminal, and a third terminal, the third terminal coupled to the second port;
a first resonator coupled between the first port and the first terminal of the transformer, the first resonator comprising a first acoustic resonator having a first characteristic and a second acoustic resonator having a second characteristic, the first acoustic resonator coupled to the second acoustic resonator;
a second resonator coupled between the first port and the second terminal of the transformer;
a third resonator coupled between the first terminal of the transformer and a ground; and
a fourth resonator coupled between the second terminal of the transformer and the ground, the fourth resonator comprising a third acoustic resonator having a third characteristic and a fourth acoustic resonator having a fourth characteristic, the third acoustic resonator coupled to the fourth acoustic resonator.