Note on the reciprocity theorem for electrical systems

Summary

It is shown by means of Maxwell’s equations that the admittance matrix of a passive linear multipole placed in a constant magnetic fieldB ₀ satisfies the extended reciprocity relationG _ik(B ₀)=G _ki(−B ₀) if the conductivity, permittivity and permeability tensors of the materials forming the multipole all satisfy the spatial symmetry relationT _αβ(B ₀)=T _βα(−B ₀).