Abstract: Transformation electromagnetics, which has become a hotspot in the research areas recently, provides a new way to manipulate electromagnetic waves with coordinate transformation method. Combined with metamaterials, several new kinds of electromagnetic devices with peculiar functions can now be designed. In this paper, a series of polyline coordinate transformation devices are summarized, among which the electromagnetic wave concentrator is mainly discussed. Based on the theories, the scattering magnifying function and the military applications of electromagnetic wave concentrators are studied through the simulations of embedded stealth aircraft models and the calculations of their scattering cross sections. Each of the parameter extremums of this device and its normalized distributions are analyzed in detail at last.