Noise Factor (F) to Noise Figure (NF):

$NF = 10 \cdot \log_{10}(F) \quad \iff \quad F = 10^{NF/10}$

Linear Gain (G) from dB:

$G = 10^{Gain_{dB}/10}$

Friis Formula for Cascaded Noise Factor:

$F_{total} = F_1 + \frac{F_2 - 1}{G_1} + \frac{F_3 - 1}{G_1 \cdot G_2} + \dots$

Note on Lossy Elements: For a passive lossy component at room temperature, its Noise Figure equals its Insertion Loss in dB ($NF_{dB} = L_{dB}$).