Hf filter using resonators having convex-concave structure

Abstract

An HF filter using resonators of a convex-concave structure is capable of easily inserting a serial or parallel capacitance inside the resonators for the sake of a characteristic improvement of frequency at a stop band desired. In the inventive HF filter, an error compensation is simple and a size smallization is available, by utilizing the resonators of the convex-concave structure. Such HF filter consists of a dielectric block having a multitude of grooves formed, in a length direction, on an upper face thereof; a plurality of resonators formed by covering a lowly constant portion of each groove with conductive material, for resonating signals inputted from the outside; a grounding electrode formed on an outer face of the dielectric block and electrically shorted with the PCB; an input electrode for receiving signals from the outside; an output electrode for outputting signals; and a first nonplating part for preventing the input and output electrodes from being electrically shorted with the grounding electrode and realizing a capacitive coupling among the input and output electrodes and its adjacent resonators, thereby being employed in a smallization of a radio communication system and an improvement of a communicative characteristic.