[1] Li Heting, Jia Qika, Zhang Shangcai, et al. Design of FELiChEM, the first infrared free-electron laser user facility in China[J]. Chinese Physics C, 41, 018102(2017).

[2] [2] Wang Qian. Study of the cavitybased bunch length diagnostic technology f linac[D]. Hefei: University of Science Technology of China, 2020

[3] Chen Jian, Leng Yongbin, Yu Luyang, et al. Beam test results of high Q CBPM prototype for SXFEL[J]. Nuclear Science and Techniques, 28, 51(2017).

[6] Guo Jiang, Zhou Zeran, Luo Qing, et al. Design and simulation of TM₀₂₀ cavity bunch length monitor[J]. High Power Laser and Particle Beams, 28, 095104(2016).

[7] [7] Pei Yuanji. Basics of electron linear accelerat design[M]. Beijing: Science Press, 2013

[8] Roberts B, Mammei R R, Poelker M, et al. Compact noninvasive electron bunch-length monitor[J]. Physical Review Accelerators and Beams, 15, 122802(2012).

[9] [9] Gan Benfu, Wu Wanchun. The structure design of modern microwave filter[M]. Beijing: Science Press, 1973

[10] [10] Jarry P, Pham J M, Roquebrun O, et al. A new class of dualmode asymmetric microwave rectangular filter[C]IEEE International Symposium on Circuits & Systems. PhoenixScottsdale: IEEE, 2002.

[11] Chen T S. Characteristics of waveguide resonant-iris filters (correspondence)[J]. IEEE Transactions on Microwave Theory and Techniques, 15, 260-262(1967).

[12] [12] Xu Ruimin, Tang Pu, Xue Zhenghui, et al. Fundamentals of microwave technology[M]. Beijing: Science Press, 2009

[13] [13] Wang Qian, Wu Y W, Luo Qing, et al. Design simulation of the waveguide coupler f the cavity beam monit[C]9th International Particle Accelerat Conference. 2018: 49324935.

[14] [14] Cui Yanyan. Studies on bunch length monit f BEPCII linac[D]. Beijing: Institute of High Energy Physics, Chinese Academy of Sciences, 2007