Filter

The invention provides a filter, relates to the technical field of filters, and is used for solving the technical problems of poor out-of-band rejection effect and incompact structure of the filter, the filter comprises a substrate and a chip arranged on the substrate, the chip comprises a first wafer and a second wafer, the first wafer and the second wafer are stacked along the thickness direction of the substrate, and the first wafer and the second wafer are stacked along the thickness direction of the substrate. The first wafer is provided with a resonator, and the second wafer is provided with a passive device; the filter is provided with a series branch and a parallel branch, the series branch is connected between the input end and the output end of the filter, the parallel branch is connected with the series branch, and the series branch and the parallel branch are respectively and correspondingly arranged at different diagonal positions of the chip. According to the filter provided by the invention, th