Abstract: A high frequency filter for frequencies higher than the VHF band comprising of a closed conductive housing (53), a pair of input and/or output means (54) like an antenna provided at both the extreme ends (53-5, 53-6) of said housing (53), a plurality of resonators (51-1 through 51-5, and 51a-1 through 51a-5) arranged on a straight line between said antennas (54), each of said resonators having an elongated inner conductor (51a-1 through 51a-5) with a circular cross section, and an elongated rectangular dielectric body (51-1 through 51-5) surrounding said inner conductor, one end of each of said resonators being fixed at the single plane (53-1) of the housing (53) and the other end of each of said resonators being free standing. The length of said inner conductor and the dielectric body is substantially 1/4 wavelength, and the duration (52-1 through 52-4 ) between two resonators is determined according to the specified coupling coefficient for the desired characteristics of the filter.

Abstract: A high frequency filter for frequencies higher than the VHF band comprises a closed conductive housing, a pair of input and/or output means like an antenna provided at both the extreme ends of said housing, a plurality of resonators arranged on a straight line between said antennas, each of said resonators having an elongated inner conductor and a cylindrical dielectric body surrounding said inner conductor, one end of each of said resonators being fixed on the single plane of the housing and the other end of each of said resonators being free standing, and the length between each of the resonators being defined according to the specified coupling coefficient for the desired characteristics of the filter.The present filter utilizes the coupling effect between resonators by the displacement current relating to surface TM mode and the conductive current relating to TEM mode. Therefore, no coupling means for providing the coupling between resonators is provided.