thanks lodeyh
but i still have the problem .
in calculator i find two function
one is foureval ,it has four param ,some param i do not know ,how can i fill in the param （from ，to and by）
another is harmonic .it has two param one is signal ,the other is harmonic number .
i fill the harmonic number is 10.
when i click the plot button ,i got wrong
how can i do
please help me
An easy to determine the THD/SFDR or whatever, is to make use of the component fourier/fourier2ch. These two components are located in analogLib and they are specific to the cadence simulator spectre. If you place them in a schematic and run a transient anaysis, you will get the fourier coefficients of the corresponding waveform. And you will also get a summary of the HD2, HD3, THD and etc.
I haven't tried out the component fourier2ch. There is more information in the cadence document. Try to use
spectre -h fourier
to get the detailed description.
There is also a very good reference in the website of Cadence. It may help you to understand more.