[1] Univ Elect Sci & Technol China, Sch Elect Sci & Engn, Chengdu 611731, Peoples R China
[2] Tianjin Univ, Sch Microelect, Tianjin Key Lab Imaging & Sensing Microelect Tech, Tianjin 300072, Peoples R China
[3] Univ Calgary, Dept Elect & Comp Engn, Calgary, AB T2N 1N4, Canada
[4] Tsinghua Univ, Dept Elect Engn, Beijing 100084, Peoples R China