% Y* ]# L' w B, T4 G4 s9 c
1 d( S3 W) d5 n% s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 4 }6 j! x+ T) a3 I
--> 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 7 N# `: F, u9 ?2 d5 }+ f* K
) N9 j. @& t0 K; D( t6 F! F, Y/ {2 t
. K. M3 U8 G0 T6 K- H
- B) Friis transmission formula: Pd = (Pout*G)/(4* Pi * R2)
- --> Pd = 1000*P*G / 4*pi*10000 r2
- --> Pd = 0.00796 * P * G / r2. j- `& o) s/ M; S; 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
" y! }! o9 }2 s9 Z! k# Y3 \& } |