Designing objects that are invisible to electromagnetic waves

This article shows that it is, in principle, possible to make a dielectric rod completely invisible to an incident electromagnetic plane wave of a given frequency. Students can derive the conditions that make the rod invisible if they understand the concept of plane waves, the boundary conditions for electric and magnetic fields, and the complex representation of electromagnetic fields. With access to appropriate software, students can determine the bandwidth of the invisibility and investigate whether it is possible to make an invisible rod out of real-world materials. A more advanced project proposed is to use electromagnetic software to find perfectly conducting hollow structures that are invisible to an incident plane wave.