The improvements of the design and the compatibility with silicon IC of RF MEMS switch are presented.The compatibility with silicon IC is realized by dielectric isolation technology,and the decrease of the pull voltag...The improvements of the design and the compatibility with silicon IC of RF MEMS switch are presented.The compatibility with silicon IC is realized by dielectric isolation technology,and the decrease of the pull voltage of the switch is done by etching some holes on the metal membrane.The preliminary test results are as follows: C off and C on are 0 32pF,6pF,respectively;the pull down voltage is about 25V.The package of the RF MEMS switch is done by micro stripline,and the isolation and the insertion loss are 35dB,2dB,respectively at 1 5GHz;the switching speed is about 3μs by oscilloscope.展开更多
Various regulations, aimed at the protection of human beings and electrical equipment against possible adverse effects resulting from exposure to electromagnetic fields, have been issued in many countries. Most of the...Various regulations, aimed at the protection of human beings and electrical equipment against possible adverse effects resulting from exposure to electromagnetic fields, have been issued in many countries. Most of them are based on safety guidelines published by international expert groups. In this paper, electric and magnetic fields are calculated in the vicinity of 25 kV traction line supplying railway traction systems. Calculation results are compared to exposure limits specified by safety guidelines and regulations. Possible countermeasures for reduction of electromagnetic fields are proposed. Also, this paper presents a method for calculation of the induced voltages to an underground gas pipeline from a neighbouring 25 kV electric traction overhead line in case of short circuit. Calculations are performed with EMTP-ATP software. Possible countermeasures for reduction of induced voltages are proposed.展开更多
The response of field electron emission of cadmium sulfide (CdS) nanowires (NWs) to visible light has been investigated.It is found that,upon light illumination,the turn-on voltage drops,emission current increases obv...The response of field electron emission of cadmium sulfide (CdS) nanowires (NWs) to visible light has been investigated.It is found that,upon light illumination,the turn-on voltage drops,emission current increases obviously,and the Fowler-Nordheim behavior deviates from a straight line.A process of field emission coupled with semiconducting properties of CdS NWs is proposed.Photon-excited electron transition from the valence band to the conductance band of CdS nanowires increases the quantity of emitting electrons,and the photoemission decreases the effective work function of CdS emitters,which largely enhances the field emission performance.The response of field emission of CdS NWs to light illumination suggests an approach for tuning field emission of semiconductor emitters.展开更多
文摘The improvements of the design and the compatibility with silicon IC of RF MEMS switch are presented.The compatibility with silicon IC is realized by dielectric isolation technology,and the decrease of the pull voltage of the switch is done by etching some holes on the metal membrane.The preliminary test results are as follows: C off and C on are 0 32pF,6pF,respectively;the pull down voltage is about 25V.The package of the RF MEMS switch is done by micro stripline,and the isolation and the insertion loss are 35dB,2dB,respectively at 1 5GHz;the switching speed is about 3μs by oscilloscope.
文摘Various regulations, aimed at the protection of human beings and electrical equipment against possible adverse effects resulting from exposure to electromagnetic fields, have been issued in many countries. Most of them are based on safety guidelines published by international expert groups. In this paper, electric and magnetic fields are calculated in the vicinity of 25 kV traction line supplying railway traction systems. Calculation results are compared to exposure limits specified by safety guidelines and regulations. Possible countermeasures for reduction of electromagnetic fields are proposed. Also, this paper presents a method for calculation of the induced voltages to an underground gas pipeline from a neighbouring 25 kV electric traction overhead line in case of short circuit. Calculations are performed with EMTP-ATP software. Possible countermeasures for reduction of induced voltages are proposed.
基金supported by the National Natural Science Foundation of China (Grant Nos. 60771060,61072136 and 60871081)
文摘The response of field electron emission of cadmium sulfide (CdS) nanowires (NWs) to visible light has been investigated.It is found that,upon light illumination,the turn-on voltage drops,emission current increases obviously,and the Fowler-Nordheim behavior deviates from a straight line.A process of field emission coupled with semiconducting properties of CdS NWs is proposed.Photon-excited electron transition from the valence band to the conductance band of CdS nanowires increases the quantity of emitting electrons,and the photoemission decreases the effective work function of CdS emitters,which largely enhances the field emission performance.The response of field emission of CdS NWs to light illumination suggests an approach for tuning field emission of semiconductor emitters.
