Resonator and filter using thereof in a communication system

The present invention has been, filter in accordance with a signal in a communication system to filter a predetermined by using a resonator and a resonator to improve the filtering RF spectral characteristics of a filter for filtering according to the frequency band to perform the filtering, and series-connected to an input terminal part resonator having a first resonant frequency; And wherein the series-connected to the first resonating part, a filtering unit for filtering a signal inputted through the input terminal; And a serial connection between the filtering unit and the output terminal, the second unit having a second resonant frequency resonance; A first zero-order resonator unit having a first zero-order resonance frequency which is parallel connected to a terminal between the input terminal and the first resonating part, match with the first resonant frequency; And it is parallel connected to a terminal between the output terminal and the second resonance part, part 2 zero-order resonator having a second zero-order resonance frequency matching the first resonant frequency; and a.