Institution: | [1]the Key Laboratory of RF Circuits and System of Ministry of Education, Hangzhou Dianzi University, Hangzhou 310018, P. R. China [2]State Key Laboratory of Transducer Technology, Chinese Academy of Sciences , Shanghai 200050, P. R. China [3]Toshiba Hydro-Electro Equipments Company, Hangzhou 311504, P. R. China |