Recent advances in metamaterial klystrons

As a kind of artificially structured media, electromagnetic metamaterials (MTMs) have exotic properties that are not found or difficult to achieve in natural materials. This class metal/dielectric-structured artificial media has attracted great attention during the past two decades and made important breakthroughs. A variety passive active devices based on MTMs been developed rapidly. Especially MTM klystrons, which show very remarkable advantages, including miniaturization, high gain, efficiency microwave band. extended interaction klystrons creatively combine advantages MTMs, technology, klystrons. It provides new design idea for development brand-new with performance. In this review paper, we report recent advances oscillator klystron amplifier. Furthermore, prospects challenges discussed. Finally, trend is concluded.