The circuit design is carried out by taking chip of RF-ID U2270B as core, including power module, frequency module, antenna module and data input;
采用以射频卡U2270B器件为核心完成支撑电路设计，包括电源模块、频率模块、天线模块和数据输入；
2
Combination of ladder approach method and equivalent circuit model of slot antenna had been used to analyze its input impedance. Finally, GTD had been used to calculate the radiation pattern.