COUPLING MATRIX DECOMPOSITION IN DESIGNS AND APPLICATIONS OF MICROWAVE FILTERS

The relationship between the immittance inverter coefficients and the coupling coefficients is obtained under the non-resonating coupling condition. With the relationship and the determinant properties of the transformation matrix, the coupling matrix could be decomposed to many sub-matrixes for filter designs. The physical significance of the decomposition is discussed. Using this idea, a filter can be decomposed to a number of sub-filters, which could be connected by sections of transmission lines with the same characteristics kept.