US 12,395,153 B2
Split-type, half-lattice micro-acoustic filter using a phase shifter and having broad bandwidth
Edgar Schmidhammer, Munich (DE)
Assigned to RF360 Singapore Pte. Ltd., Republic Plaza (SG)
Appl. No. 17/288,410
Filed by RF360 Singapore Pte. Ltd., Republic Plaza (SG)
PCT Filed Nov. 27, 2019, PCT No. PCT/EP2019/082682
§ 371(c)(1), (2) Date Apr. 23, 2021,
PCT Pub. No. WO2020/114849, PCT Pub. Date Jun. 11, 2020.
Claims priority of application No. 10 2018 131 054.4 (DE), filed on Dec. 5, 2018.
Prior Publication US 2021/0384890 A1, Dec. 9, 2021
Int. Cl. H03H 9/64 (2006.01); H03H 7/12 (2006.01); H03H 7/19 (2006.01); H03H 7/38 (2006.01)
CPC H03H 9/6406 (2013.01) [H03H 7/12 (2013.01); H03H 7/19 (2013.01); H03H 7/38 (2013.01); H03H 9/6433 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A micro-acoustic RF filter, comprising:
a first port and a second port;
a first node coupled to the first port;
a second node coupled to the second port;
a first signal path coupled between the first node and the second node, the first signal path including a first resonator;
a second signal path coupled between the first node and the second node, the second signal path including a second resonator and a phase shifter connected in series to the second resonator, wherein at least one of the first resonator or the second resonator comprises a micro-acoustic resonator;
a third resonator, wherein the third resonator comprises an additional micro-acoustic resonator having a first end coupled directly to the second node and a second end coupled to a reference node; and
a fourth resonator having a first end coupled to the first port and a second end coupled directly to the first node,
wherein the third resonator and the fourth resonator are configured to provide a finite transmission zero (FTZ) function outside of a passband, and
wherein the first resonator, the second resonator, and the phase shifter configure a frequency response within the passband, and
wherein each of the first resonator, the second resonator, and the fourth resonator comprise a pair of resonators connected in anti-series having opposite polarities.