Re: [Maxima-discuss] Finding the magnitude-squared of a transfer function

[Soegtrop, M. <mic...@in...>]

Dear Fei,

unless I misunderstand something, this is quite easy, just insert %i*omega into H and compute the square of the complex abs:

(%i1)      H(s):=ω_n^2/(s^2+2*ζ*ω_n*s+ω_n^2);
(%i2)     subst(ζ=1/(2*Q),cabs(H(%i*ω))^2);
(%o2)    ω_n^4/((ω_n^2-ω^2)^2+(ω^2*ω_n^2)/Q^2)

Best regards,

Michael
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