PZ分析失败，求助

ddrr

电路含bjt。


设置eval freq.=200K:

****************
PZ Analysis `pz'
****************

Warning from spectre during PZ analysis `pz'.
    Bipolar Junction Transistor - frequency dependent components are present in
        the circuit, approximated as AC equivalents at 2.000000e+05Hz for pz
        analysis.
    ahdl module - frequency dependent components are present in the circuit,
        approximated as AC equivalents at 2.000000e+05Hz for pz analysis.

Trying `homotopy = gmin'.
  No pole is found

  No zero is found

Accumulated DC solution time = 70 ms.
Intrinsic pz analysis time = 290 ms.
Total time required for pz analysis `pz' was 360 ms.


设置eval freq.=300K:

****************
PZ Analysis `pz'
****************

Warning from spectre during PZ analysis `pz'.
    Bipolar Junction Transistor - frequency dependent components are present in
        the circuit, approximated as AC equivalents at 3.000000e+05Hz for pz
        analysis.
    ahdl module - frequency dependent components are present in the circuit,
        approximated as AC equivalents at 3.000000e+05Hz for pz analysis.

Trying `homotopy = gmin'.
  No pole is found

  No zero is found

Accumulated DC solution time = 70 ms.
Intrinsic pz analysis time = 280 ms.
Total time required for pz analysis `pz' was 350 ms.

ddrr

有什么解决或者替代的方法？

帮助里说：
PZ Analysis (pz)
Description

The PZ analysis linearizes the circuit about the DC operating point and computes the poles and zeros of the linearized network. To compute zeros, users need to specify input sources and output voltages or currents. If no input or output are given, then only poles are computed. In case there are frequency dependent components, poles and zeros are computed by approximating those components as equivalent conductances and capacitances evaluated at 1Hz. The PZ analysis currently uses direct solver for better accuracy. Small to medium circuit size will achieve better performance.

(Note: A frequency dependent component means the capacitance or conductance equivalent representation of the component is freqency varying. Examples are transimission lines or bjts with excess phases. A linear capacitor is not a frequency dependent component.)

donnaxin

频率设太低了吧

ddrr

No one know it? please, help!

kyoabc

不知道你怎么写的网表，所以看不出来！！

RF小白

我的电路也含有BJT，也报了相同的错！好像就是那段英文说的原因，没办法仿真。