C Band Waveguide Harmonic Filter

A rigorous theoretical analysis method—mode matching(MM) method is introduced to analyze waveguide harmonic absorption filter by using general scating matrix of large aperture coupling ET junction and of waveguide double step discontinuity. Mode matching is rigorous at theory. It is also introduced truncation error because of finity number of modes with view of calculating efficiency. It is very difficult to analyze the whole frequency performance of waveguide absorption harmonicfilter. An engineering approximately design method-equivlent circuit isalso introduced by equilent circuit of waveguide ET-junction and principle of symmetry and of multiplication of [A] matrix.It is approximately but very efficiency. It can be used to calculating whole frequency band performance of the filter. It is proved by experiment that the filters designed by equivlent circuit achieve to the international level of same type filter.