Nonreflecting impedance planes and plane figures

It is demonstrated that, when the function describing the impedance distribution on a plane belongs to a certain class, a wave normally incident on the plane is diffusively scattered and absorbed rather than reflected. When the contour of a finite plane segment satisfies a certain condition, a wave is not reflected by this segment. Such plane figures can provide for antiradar protection. In particular, they can be made from a lossless material.