Baw resonator and baw filter for reducing harmonic distortion

A BAW filter, comprising:

• a series BAW resonance circuit comprising series BAW resonators disposed on a substrate and connected in series between a first terminal and a second terminal;
• and
• a shunt BAW resonance circuit comprising shunt BAW resonators disposed on the substrate and connected between respective electrodes of the series BAW resonators and a ground,
• wherein one of the shunt BAW resonators comprises
• a first BAW resonator comprising a first air cavity disposed in the substrate, and further comprising a first electrode, a first piezoelectric layer, and a second electrode stacked on the first air cavity,
• a second BAW resonator comprising a second air cavity disposed in the substrate, and further comprising a first electrode, a second piezoelectric layer, and a second electrode stacked on the second air cavity, the second BAW resonator being connected in parallel to the first BAW resonator and comprising polarities that are opposite of polarities of the first BAW resonator, and
• a compensation capacitor circuit connected between the first BAW resonator and the second BAW resonator.