Abstract: The present disclosure relates to filters and preparation methods of the filters. One example filter includes a substrate, a series resonator, a parallel resonator, and a series branch. The series resonator includes a first Bragg reflection layer and a first piezoelectric transduction structure that are sequentially stacked on the substrate. The parallel resonator includes a second Bragg reflection layer and a second piezoelectric transduction structure that are sequentially stacked on the substrate, and a structure of the first Bragg reflection layer is different from a structure of the second Bragg reflection layer. The series branch includes the series resonator, and the series branch is coupled between an input end of the filter and an output end of the filter.

Abstract: Disclosed are a resonator and a manufacturing method thereof, a filter, and an electronic device. The resonator includes a substrate, a Bragg reflection layer, and a piezoelectric layer that are sequentially stacked. A first electrode is disposed on a surface that is of the piezoelectric layer and that faces the Bragg reflection layer, a second electrode is disposed on a surface that is of the piezoelectric layer and that is away from the Bragg reflection layer, a border ring is disposed on a surface that is of the second electrode and that is away from the piezoelectric layer, and the resonator has a first resonance region and a second resonance region corresponding to the border ring.

Abstract: A package antenna apparatus including a package substrate, wherein an antenna array is disposed on the package substrate, and a transceiver chip coupled to the antenna array, where the transceiver chip is fastened to the package substrate, and the transceiver chip has a first pad and a second pad, and a filter disposed on the package substrate, where the filter comprises an input port and an output port, the input port is coupled to the first pad of the transceiver chip, the output port is coupled to the second pad of the transceiver chip, and the filter is configured to filter a signal of the transceiver chip that is input through the input port, and is further configured to output a filtered signal to the transceiver chip through the output port.