Abstract: In this paper, the GNES approach is applied to calculate the capacities of directional couplers. The high precision calculation of matrix elements and accuracy analysis are discussed.The numerical results of its capacities for different configurations(the symmetric and asymmetric,coaxal and non-coaxial double-cylinders and double elliptic cylinders) inner conductors are presented.The practical calculation shows that the GNES approach is successful in high accurate calculation with bigh speed and is the one of the best modern approaches.

Key words: coefficients of capacity, double cylinders, directional coupler, GNES approach, double elliptic cylinders