High-power microwaves (HPMs), or directed energy RF, is an evolution of vacuum electron devices (VEDs) that seeks to generate the highest peak power levels in the frequency range of 100 MHz through 100 GHz (and even higher frequencies) in short pulses (10–100 s ns in duration) that can

be repetitively pulsed. In 1967, Veselago theoretically investigated exotic electromagnetic properties of matamaterials (MTMs) such as negative refractive index, reversed Doppler effect, and reversed Cherenkov radiation (RCR) in an assumed homogeneous isotropic material in which the real parts of the permittivity and the permeability are both negative. In many VEDs, the particle wave interaction is mediated in part via a material, where the functionality of the material manipulates the electromagnetic (EM) wave in a controlled fashion. And the permittivity (εeff(ω)) and the permeability (μeff(ω)) are the complex averaged EM response functions of the molecules that make up the material due to the interaction with the electric and magnetic components of an incident wave. The creativity of engineers to construct new devices is by designing the EM properties of and structures of available materials to get the permittivity (εeff(ω)) and the permeability (μeff(ω)) and thus they are able to precision engineer geometries from these materials. There have been emerging fields in HPMs and VEDs as well as their components using MTMs research, such as HPM device miniranization, frequency agility in HPM device, HPM antenna using MTMs, HPM phase shifter et al as well as Pulsed Power System using MTMs, representing a variety of MTMs applications.