1μV转换为dBm单位的值后应为

Question

如题所述

Answer 1

dBV = 20*Log10(V/V_ref) = 20*Log10(V) - 20*Log10(V_ref);
dBm = 10*Log10(P(mW));
P(w) = V*V/R_ref;
dBm = 10*Log10(P*1000)
= 10*Log10(V*V/R_ref)+30
= 20*Log10(V) - 10*Log10(R_ref) + 30
= dBV + 20*Log10(V_ref) - 10*Log10(R_ref) + 30
当V_ref = 1V;
R_ref = 50欧姆
dBm = dBV + 13
即1V等于13dbm