Cavity filter, connector and manufacturing processes thereof

A cavity filter, comprising a cavity, a cover plate and a connector disposed on the cavity or the cover plate, an end of the connector being connected with internal devices inside the cavity filter and the other end of the connector being connected with external communication devices, wherein the connector comprises an inner conductor and a metal enclosure disposed coaxially and an insulation medium disposed between the metal enclosure and the inner conductor, and a non-metal layer is disposed to cover an outer peripheral surface of the metal enclosure, the metal enclosure comprises a cylindrical portion and a flange portion located at an end of the cylindrical portion, and the flange portion comprises a first end surface that connects with the cylindrical portion and a second end surface that is away from the cylindrical portion, the connector is connected to the cavity filter, the flange portion of the metal enclosure is located on an outer surface of the cavity of the cavity filter, and the second end surface of the flange portion that is away from the cylindrical portion makes contact with the outer surface of the cavity of the cavity filter, the flange portion defines an annular groove surrounding the insulation medium, and a seal ring is totally disposed within the annular groove for contacting with the cavity filter, wherein the non-metal layer covers an outer peripheral surface of the cylindrical portion of the connector, the first end surface of the flange portion that connects with the cylindrical portion, an interior of the annular groove, and an area from the annular groove to an outer edge of the flange portion.