Question 8.11: Using SPICE and Eq. (8.46), calculate the noise factor of th......
Using SPICE and Eq. (8.46), calculate the noise factor of the circuit in Ex. 8.10 (verify, once again, that it is 11).
F=\frac{\mathrm{total~output~noise~power}}{\mathrm{total~output~noise~power-total~output~noise~power~with}\ R_s\ \text{noiseless}} (8.46)
Step-by-Step
Again, as determined in Ex. 8.5, the total output noise power for this circuit is 1.5053\times10^{-14}{{V}}^{2}. If we simulate the noise performance of the circuit in Fig. 8.21 with R_s being noiseless, we get
TEMP=27 deg C
Noise analysis … 100%
inoise_total = 1.655918e-12
onoise_total = 1.368527e-14
Using Eq. (8.46), we get
F=\frac{1.5053\times10^{-14}}{1.5053\times10^{-14}-1.3685\times10^{-14}}=11Simulating with a noiseless source resistor is the preferred way to simulate NF with SPICE.
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