Periodic arrays of negative capacitance shunted piezoelectric patches are employed to control the band gaps of phononic beams. The location and the extent of induced band gap depend on the mismatch in impedance genera...Periodic arrays of negative capacitance shunted piezoelectric patches are employed to control the band gaps of phononic beams. The location and the extent of induced band gap depend on the mismatch in impedance generated by each patch. The total impedance mismatch is determined by the added mass and stiffness of each patch as well as the shunting electrical impedance. Therefore, the band gap of the shunted phononic beam can be actively tuned by appropriately selecting the value of negative capacitance. The control of the band gap of phononic beam with negative capacitive shunt is demonstrated numerically by employing transfer matrix method. The result reveals that using negative capacitive shunt to tune the band gap is effective.展开更多
This paper describes a fixed-fixed beam ohmic switch in series with a fixed capacitor as a replacement for a capacitive switch.In this switch,a metal plate deposited on the dielectric ensures perfectly contact with th...This paper describes a fixed-fixed beam ohmic switch in series with a fixed capacitor as a replacement for a capacitive switch.In this switch,a metal plate deposited on the dielectric ensures perfectly contact with the dielectric layer in the down state.The area size of the metal plate directly influences the capacitance ratio of the switch,as the area size of the metal cap decreases,the capacitance ratio dramatically rises up.The down/up capacitance ratio can exceed 800 times over the conventional designs using the same materials and the equal size.Measurement results show that high capacitance ratio of the switches has a large effect on the isolation,and can actually improve the performance of the switches.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50875255 and 10902123)
文摘Periodic arrays of negative capacitance shunted piezoelectric patches are employed to control the band gaps of phononic beams. The location and the extent of induced band gap depend on the mismatch in impedance generated by each patch. The total impedance mismatch is determined by the added mass and stiffness of each patch as well as the shunting electrical impedance. Therefore, the band gap of the shunted phononic beam can be actively tuned by appropriately selecting the value of negative capacitance. The control of the band gap of phononic beam with negative capacitive shunt is demonstrated numerically by employing transfer matrix method. The result reveals that using negative capacitive shunt to tune the band gap is effective.
文摘This paper describes a fixed-fixed beam ohmic switch in series with a fixed capacitor as a replacement for a capacitive switch.In this switch,a metal plate deposited on the dielectric ensures perfectly contact with the dielectric layer in the down state.The area size of the metal plate directly influences the capacitance ratio of the switch,as the area size of the metal cap decreases,the capacitance ratio dramatically rises up.The down/up capacitance ratio can exceed 800 times over the conventional designs using the same materials and the equal size.Measurement results show that high capacitance ratio of the switches has a large effect on the isolation,and can actually improve the performance of the switches.
