xxgeneral
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Hi guys,
I've gotten something unsure about noise factor. Hope for help here.
The Noise Factor is defined as below. N = (Na+G*Ns)/(G*Ns). Different Ns produces different N. And in Cadence spectre, the noise source is usually a port. The impedance of the port provides the thermal noise 4kTRB V^2, which is related to the value of R. Q1: What value of R should be set? Q2: If R=50 Ohm, why? Q3: If R=Rout of the preceding device, then noise factor of the DUV(Device Under Test) is dependent on different source impedances. So noise factor is not a general performance factor of DUV for comparison, isn't it?
Anyone can help me? Thanks in advance.
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