JPS5737902A - Dielectric filter - Google Patents

Abstract

PURPOSE:To obtain a dielectric filter that has a small loss at the UHF bands of <=1GHz and the sharp cut-off property, by arranging the magnetic cores of plural ceramic dielectric cylinder materials through which the high frequency magnetic flux passes with the fixed spaces and virtually in parallel to each other and then attaching these cores to the inner wall of a waveguide. CONSTITUTION:Ceramic dielectric cylinder materials 3A-3D which are used as magnetic cores are provided in parallel to each other around lines 2A-2D with open ends formed into disks respectively. The lower end of each mateials is positioned at a hole 5 provided on the inner wall of a conductor case 1 functioning as a square waveguide. Making use of this hole 5, the lines 2A-2D are fixed with screws 6 and after giving an adjustment to the mutual positions. Thereafter, a conductor cover 10 containing disk-shaped capacity electrodes 11A-11D opposite to the lines 2A-2D respectively is put on the upper open end side of the case 1, and then coaxial contact plugs 13 and 14 formed at the outer sides across the case 1 are connected to the cylinder materials 3A and 3D via loops 15 and 16 respectively. In such way, the distribution of electromagnetic field can be improved within a waveguide, and at the same time a dielectric filter can be miniaturized.