中文摘要：

利用二维三角格子金属光子带隙谐振腔代替回旋管的传统柱形谐振腔,并对腔体进行了TE波模式的计算与分析.综合考虑腔体内外的结构特征,给出了光子带隙谐振腔冷腔模式理论的研究方法,发现腔内存在单模工作的可能与条件以及非角对称情况下的电磁模式分布特征.研究结果表明,利用光子带隙谐振腔代替回旋管的传统腔体,可使回旋管在不受腔体横向尺度限制的条件下实现单模工作.这对于提高回旋管的功率容量、有效实现高次单模与高次回旋谐波耦合条件下的注-波互作用、降低工作磁场并从物理上根本改变回旋管的工作状态提供了理论依据.

英文摘要：

The traditional cylindrical resonant cavity loaded in gyrotron is substituted by the photonic-band-gap resonant cavity（PBGC） which is constructed by triangular arrays of metal posts,and the TE operating modes in PBGC are analyzed and calculated. Under the consideration of the cavity structure features,a research method for the mode theory on PBGC is provided. The single-mode operation in the cavity is found,and the distribution characteristics of the azimuthally inhomogeneous electromagnetic modes are reported. The research results show that the resonant frequency in the cavity can be excited without the limitation of transverse dimension. The study provides a physical theoretical fundamental of which reveals the possibility of changing the operating status of gyrotron essentially. This possibility will play an important role in the following aspects：enhancing the power capacity of cavity,carrying out the beam-wave interaction between high order electromagnetic single-mode and high electronics cyclotron harmonic wave efficiently,and reducing the gyrotron operating magnetic field.