& w4 b) P, j; [. r+ i0 w/ R
- H5 q6 z9 k: {* y求教大神FCC RF MPE评估的两套公式是否完全等价?但是把它们变形后发现结果相差1个数量级啊,还请大神能够帮忙看看,谢谢。A)E= √(30xPxG)/d and S=E2/377
$ }0 e9 u# s( n+ O
--> E= (30xPxG)/(377d2) --> E=0.0796xPxG/d2 Where E=Field strength in Volts/meter P=Power in Watts G =Numeric antenna gain d =Distance in meters S =Power density in milliwatts / square centimeter 9 ~) h: X R9 u+ t. g- h0 x; s
2 X: h' p' p! x% b" @; j$ o9 Y1 |
9 d: @" B& {+ G - B) Friis transmission formula: Pd = (Pout*G)/(4* Pi * R2)
- --> Pd = 1000*P*G / 4*pi*10000 r2
- --> Pd = 0.00796 * P * G / r2
5 H' i: {9 m# D7 F& z4 S$ {4 Y' e
Where Pd = power density inmW/cm2 Pout = output power toantenna in mW G = gain of antenna inlinear scale Pi = 3.1416 R = distance betweenobservation point and center of the radiator in cm
) X# d) M& b/ c; l6 \( l |