US 12,438,520 B2
Electroacoustic filter with low phase delay for multiplexed signals
Oswaldo Ramos Sparrow, Lorient (FR); and Lionel Treffon, Vallauris (FR)
Assigned to RF360 Singapore Pte. Ltd., Republic Plaza (SG)
Filed by RF360 Singapore Pte. Ltd., Republic Plaza (SG)
Filed on Sep. 1, 2021, as Appl. No. 17/464,592.
Prior Publication US 2023/0061645 A1, Mar. 2, 2023
Int. Cl. H03H 9/56 (2006.01); H03H 9/13 (2006.01); H03H 9/54 (2006.01)
CPC H03H 9/568 (2013.01) [H03H 9/13 (2013.01); H03H 9/547 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A wireless communication apparatus comprising:
a first acoustic resonator that is a part of a first bandpass filter having a first passband, the first acoustic resonator having a first resonator side and a second resonator side, the first resonator side coupled to a circuitry connection port, and the second resonator side coupled to a communication connection port;
a second acoustic resonator that is part of a notch filter having a stopband, the second acoustic resonator having a first resonator side and a second resonator side, the second acoustic resonator coupled in parallel to the first acoustic resonator with the first resonator side of the second acoustic resonator directly coupled to the first resonator side of the first acoustic resonator, and the second resonator side of the first acoustic resonator directly coupled to the second resonator side of the second acoustic resonator;
a third acoustic resonator that is part of the first bandpass filter, the third acoustic resonator having a first resonator side and a second resonator side, the first resonator side of the third acoustic resonator directly coupled to the second resonator side of the first acoustic resonator, and the second resonator side of the third acoustic resonator directly coupled to a reference potential; and
a fourth acoustic resonator that is part of the notch filter, the fourth acoustic resonator having a first resonator side and a second resonator side, the fourth acoustic resonator coupled in parallel to the third acoustic resonator, with the first resonator side of the fourth acoustic resonator directly coupled to the second resonator side of the first acoustic resonator, and the second resonator side of the third acoustic resonator directly coupled to the second resonator side of the fourth acoustic resonator and the reference potential,
wherein resonance values associated with the first acoustic resonator and the third acoustic resonator forming the first bandpass filter are less than resonance values associated with the second acoustic resonator and the fourth acoustic resonator forming the notch filter, and
wherein a resonant frequency of the second acoustic resonator and an antiresonant frequency of the fourth acoustic resonator are within a range of less than 100 megahertz (MHz).