Some practical and theoretical aspects of the Calderon-preconditioned EFIE

The Calderon identities have recently gained attention by providing a way to analytically precondition the electric field integral equation (EFIE). In their current state, however, these pre-conditioners are not perfect, having both nonobvious practical difficulties and explicitly stated theoretical limitations. An example of the former is the difficulty in discretizing the preconditioner, while the latter include problems with nonsmooth surfaces and internal resonance. This paper will discuss and illustrate, through numerical examples, how some of these issues have been resolved and how others provide opportunities for future research work.