| 摘要 |
An overvoltage protection device on a radio frequency identification tag or in a radio frequency receiver comprises electro-magnetic coupling means between a base station and the radio frequency identification tag or radio frequency receiver. At least one ferroelectric capacitor is electrically connected to the coupling means. As long as the voltage across the ferroelectric capacitor remains below its coercive voltage, its capacitance will be linear and the tag or radio frequency receiver will behave normally. However, if the voltage across the ferroelectric capacitor exceeds the coercive voltage, the ferroelectric capacitance will experience polarization reversal and exhibit its non-linear and dissipative behavior. Connecting the ferroelectric capacitor in suitable ways to the coupling means will result in dumping of the voltage transferred to the electronics present on the tag or in the radio frequency receiver. As a result, the electronics is protected against excessive voltages that could cause damage thereto.
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