Bode problem with s^5 in transfer function numerator

Dear all,

I am using a transfer function to describe filter system but it seems once the function has expression of delay components

(ex. the numerator expression is: a*s^N + b*s^(N-1) + ... + z*s^M, M>=0),

bode function will show every odd frequency response for numerator has larger than s^5 or above delays (ex. M>=5)

I suppose this is caused by positive feedback of S>4 (90 degrees X 4) and hope this problem can be confirmed by Matlab. I also hope this small flaw can be fixed in new bode analysis function.

Thank you.

[Arkadiy Turevskiy]

Can you post the code, the bode plot you get, and detailed explanation of why you think it is wrong. Also please specify what verion you are using (do >>ver ).

Otherwise, your request is vague and difficult to follow up on.