The invention relates to a cavity filter device and a cavity cover plate
assembly thereof. A cover plate comprises a substrate, a
metal layer covering the outer surface of the substrate and
metal sheets formed on the inner surface of the substrate. Debugging via holes are formed in the positions, corresponding to resonant cavities and a
coupling channel, of the cover plate. The cover plate of a printed
board structure is adopted to replace a traditional
metal cover plate, the metal layer is matched with the metal cavity to form a closed shielding space, and the metal sheets are coupled or electrically connected with the corresponding resonant columns, so that the resonant frequency is effectively reduced. Therefore, under the condition that the movable resonant column with the disc is notused, the corresponding index requirement can be met, and therefore only the metal cavity with small height is needed. By controlling the depth of a tuning rod inserted into the metal cavity, the adjustable resonant frequency and
coupling amount can be realized. Moreover, the surplus part of the tuning rod is sheared, and the
tail end of the tuning rod is flush with the outer surface of the coverplate. Therefore, the cavity filter device can realize
miniaturization, light weight and low cost while ensuring excellent electrical indexes.