[Wu, Yanjie; Lin, Hai; Xiong, Jie; Lin, H; Shi, Xintong; Li, Qiuyu] Cent China Normal Univ, Coll Phys Sci & Technol, Wuhan 430079, Hubei, Peoples R China.
[Wu, Yanjie; Hu, Haoquan; Tian, Jing] Univ Elect Sci & Technol China, Sch Elect Sci & Engn, Chengdu 611731, Sichuan, Peoples R China.
[Wu, Bian; Zhang, Ding] Xidian Univ, Natl Key Lab Antennas & Microwave Technol, Xian 710071, Shaanxi, Peoples R China.
[Xiong, Jie] HuangGang Normal Univ, Sch Phys & Telecommun, Huanggang 438000, Hubei Province, Peoples R China.
[Liu, Y.] Hubei Univ, Sch Phys, Dept Phys, Wuhan 430062, Hubei, Peoples R China.