运算放大器扩展功能，在电子电路设计中其数学模型为放大电路，含移相电容、反馈电阻及输入阻抗。

In circuit design, the mathematical model of operational amplifier expanded function is expanded circuit. The circuit includes phase electric capacity, the feedback resistance and the input impedance.

youdao

利用阶梯近似方法结合缝隙天线电路模型分析其输入阻抗，最后采用GTD方法计算该种天线的辐射方向图。

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.

youdao

为了方便设计有源集成天线，本文提出了基于微带天线输入阻抗宽带模型的有源集成天线设计方法。

For convenience of AIA design, the AIA design method based on the input impedance wide-band model of patch antenna is used in this paper.

youdao