对IIR的脉冲响应不变法、阶跃响应不变法、双线性变换法和直接设计法进行研究，得出IIR难以满足要求的结论。

For IIR, after researching Pulse Response Method, Step Response Method, Bilinear Transform Method, Direct Design Method, it is found that IIR is unsatisfactory.

youdao

对IIR的脉冲响应不变法、阶跃响应不变法、双线性变换法和直接设计法进行研究，得出IIR难以满足要求的结论。

For IIR, after researching Pulse Response Method, Step Response Method, Bilinear Transform Method, Direct Design Method, it is found that IIR is unsatisfactory.

youdao