If you are using SPICE as the simulator, running at voltage mode control, switch frequency is high enough, and can acceptable the average mode.
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These may be able to help. On the other hand, if you running at Simulink (Matlab), try to write down the state space equation on the the inductor and capacitor, then you can get the loop gain.
thank you for this site
i will do the simulation of buck converter in tensin model , but i have problem in the value of duty cycle D
if you have any adea help me please
thanks