High power microwave generation from a metamaterial waveguide

In this paper we present the microwave measurements from a backward-wave oscillator (BWO) that uses a negative index mode in a waveguide filled with a metamaterial. The metamaterial waveguide supports a mode with negative group velocity that is used to generate microwaves at 2.4 GHz by interacting with a 500 keV, 80 A electron beam. The waveguide is fabricated with complementary-split-ring-resonators (CSRRS) and is all metallic to allow for high power operation. Over 1 MW of microwave power has been measured from the device.