FILTER UNIT AND FILTER

A filter unit and a filter are provided. The filter unit includes two stacked cavities. Each cavity includes a dielectric substrate, and two surfaces of the dielectric substrate are each provided with a metal covering layer. Connected coupling slots and a row of metal slots parallel to the coupling slots are etched on a metal covering layer, one end of a coupling slot is an open end, the other end is a closed end, the open end corresponds to a magnetic wall structure, and the closed end corresponds to an electric wall structure. The two cavities are coupled and connected by using the coupling slots. In the foregoing technical solution, the two cavities are stacked to form the filter unit, the two cavities are coupled and connected by using the provided coupling slots to form the filter unit, and only a feeding port needs to be disposed on a hypotenuse of a cavity. When the foregoing structure is used, a physical size of a conventional filter is effectively reduced, and a planar area of the filter unit is reduced.