In the non - coaxial bwo of l - band , the radius of the slow - wave structure is very large , and the volume and weight of the guiding - magnetic system are also very large . thus , the non - coaxial bwo of l - band is bulky and lumbersome and is inconvenient for real application 若采用非同轴相对论返波振荡器实现l波段的微波输出,则要求慢波结构的平均半径很大,导引磁场系统的体积和重量会变得较大,这给器件的小型化带来了很大的困难。
