Mutual impedance of electric dipoles

The system of two electric dipoles, separated by distance, that is less than a wavelength, is examined. Axes of dipoles are parallel and it is accepted, that electromagnetic mutual coupling between them exists. Described system can be considered as slowing structure for the cases of decameter or hectometer waves. Analytical formulas for the calculation of active and reactive parts of mutual impedance of dipoles are presented. Distance between dipoles and displacement of their ends in terms of wavelength are used as arguments in the proposed formulas.