The results of the communication transmission characteristics appear to be erroneous

The transmission characteristics calculated using QSPICE are inconsistent with the transmission characteristic curves obtained from TIAN. The results from TIAN align with my calculations, and I would like to understand the underlying reasons for this discrepancy.


TLBO.qsch (8.0 KB)

Qspice counts correctly!


The results do not align with my calculations.

You math with frequency plot from 1Hz to 1kHz and your simulation is 1mHz to 100kHz.

Ideal opamp model compares with your laplace H(s) equation with same frequency range of operation, they are basically identical.

TLBO-IdealModel.qsch (11.5 KB)

and here with TL074 subcircuit model, where high frequency started to deviate as opamp gain reduced at high frequency.
TLBO-TL074.qsch (10.2 KB)