Power-energy relations of electrodynamics for space-dispersive active media

Electronics Department, Electrotechnical University, Saint Petersburg, 197376, Russia

Corresponding author: barybin@mail.ru

Received: 6 May 2002
Revised: 10 January 2003
Accepted: 4 March 2003
Published online: 14 May 2003

Abstract

A known electrodynamic approach is generalized to guided-wave structures using a hypothetical space-dispersive medium with drifting charge carriers and simultaneously possessing elastic, piezoelectric, and magnetic properties. On the basis of Maxwell's equations along with the appropriate equations of medium motion, the power-energy theorem is derived in the general form involving additional contributions from specific properties of the medium. The general power-energy relation yields particular expressions obtained previously for specific cases of the elastic piezo-dielectrics, magnetized ferrites, and drifting charge carriers in nondegenerate plasmas. Substantial features of our electrodynamic study are the allowance for medium losses and the separation of potential fields peculiar to the slow quasi-static waves which propagate in such active media independently of the fast electromagnetic waves of curl nature. Separating the potential fields gives a certain modification of electromagnetic terms in the power-energy theorem.