Filter device, RF front-end device and wireless communication device

A filter device, comprising:

• a substrate, a passive device and at least one resonance device, wherein:
• the passive device has a first side and a second side opposite to the first side, the substrate is located on the first side, and the at least one resonance device is located on the second side;
• the at least one resonance device includes a first resonance device, the first resonance device comprises a first intermediate layer, the first intermediate layer has a third side and a fourth side opposite to the third side, and the passive device is located on the third side;
• the first intermediate layer further has a first cavity located in the fourth side;
• the first resonance device further comprises a first electrode layer, a first piezoelectric layer and a second electrode layer;
• at least one terminal of the first electrode layer is located in the first cavity;
• the first piezoelectric layer is located on the fourth side and disposed on the first electrode layer, is a flat layer and at least covers the first cavity;
• the second electrode layer is located on the first piezoelectric layer;
• and
• the first electrode layer and the second electrode layer are respectively located on two sides of the piezoelectric layer.