Scilab Function
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closedloop - synthesizer closed loop transfert function



Compute the closed-loop transfert function of a frequency synthesizer of a second order loop of type 2, defined as :

$\displaystyle B\left(s\right)$ $\displaystyle =$ $\displaystyle \frac{G\left(s\right)}{1+G\left(s\right)H\left(s\right)},$  

with G(s) the transfert function of the direct gain and H(s) the transfert function of the feedback gain :
$\displaystyle G\left(s\right)$ $\displaystyle =$ $\displaystyle K_{\rm v}K_{\rm cp}\frac{F\left(s\right)}{s},$  
$\displaystyle H\left(s\right)$ $\displaystyle =$ $\displaystyle \frac{1}{N},$  

with Kv the sensitivity of the VCO in rad/v, Kcp the PFD gain in A/rad, F(s) the transfert function of the loop filter and N the value of the feedback divider.

Calling Sequence

B = closedloop(F,kv,Icp,N)


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See Also


A. Layec A. Layec


[1] U. Rhode, Digital PLL Frequency Synthesizers.Prentice Hall, 1983.