Thanks for those two replies, the original post about frequency production limit came from an email that I addressed to marnaw about 10 Khz to 18 Khz 3-phase sine wave.
I found this and marnaw is in the pdf file.(I)
I did not be able to contact the author and he claimed of 13 Khz, I think it's about switching pwm, don't you ?
So, first, my question still pertain : does I really need a dedicated dds to perform my signals ?
Second, does marnaw work deal with this, sometimes also called magic sine waves ?(II)
Best regards.
Sril
Edit (09/23/11) :
(I) is a non finish student work about control motor, does not need to be read, sorry.
(II) deal with a method to suppress harmony under a certain level from base frequency and is not the same as described heare, sorry.
I insist to present my apologizes for stupid lost time to read me.
Go-on my work with a 3-phased generating circuit.