Radiation resistance of antennas in anisotropic media

The note presents some observations on the behaviour of the radiation resistance of antennas in anisotropic media. It discusses the recently published results of Seshadri on the radiation resistance of an antenna in a simple anisotropic medium, and shows their relationship to the expressions published by Balmain for a general medium. The anomalous behaviour of the resistance and the absence of anomalies in a realistic model are discussed.