[6] Zhang Hao, Kang Wei, Wu Wen. Balanced bandpass filter with tunable centre frequency based on substrate integrated waveguide technology[J]. Electron Lett, 53, 886-888(2018).
[9] Chu Peng, Wu Ke. Balanced dual-mode SIW filter[J]. Electron. Lett, 55, 208-210(2019).
[19] Pozar D M. Microwave engineering[M]. 3rd Ed. New Yk: Wiley Press, 2005.
[20] Hong Jiasheng. Microstrip filters f RFmicrowave applications[M]. New Yk: John Wiley & Sons, Inc, 2001.