Filter of high out-of-band rejection

The utility model relates to a filter of high out-of-band rejection. The filter is characterized by comprising a top surface and a bottom surface, two through holes are formed between the top and bottom surfaces, and recess areas are respectively arranged at the positions of the through holes of the bottom surface. The filter can realize high rejection on the basis that the amount of holes and the size are not increased, the design of a circuit surface is simplified, printing of the whole circuit is omitted, the two through holes are directly coupled to form a passband, coating of a silver layer is omitted, and thus, the cost is reduced and the technology is simplified.