The Number of Independent Current Components in Shockley-Ramo Theorem

Shockley-Ramo theorem describes the currents from external circuit into several metal electrodes, induced by point charge, moving in the vacuum space between electrodes in electro vacuum devices. It was generalized for the case of any number of moving and fixed charges in vacuum or in solid state structures with dielectrics and was used for description of processes in superhighfrequency electro vacuum and semiconductor devices, sensing elements for ionizing radiation, integrated circuits and so on. But, except induced currents (and simultaneously with them), there exist other currents of different nature, which are not described by Shockley-Ramo theorem. Author has shown, that there exist four independent contributions into external circuit currents. They are induced currents, currents of capacity nature, currents induced by the changing of device parameters (dielectric permittivity), and currents, related with the possible asymmetry of dielectric permittivity tensor. Corresponding expressions for discussed current components are presented.