[ 举例] 设:PT = 10 W = 40dBmw ;GR = GT = 7 (dBi) ; f = 1910MHz
问:R = 500 m 时, PR = ?
解答: (1) L0 (dB) 的计算
L0 (dB) = 32.45 + 20 Lg 1910( MHz ) + 20 Lg 0.5 ( km ) - GR (dB) - GT (dB)
= 32.45 + 65.62 - 6 - 7 - 7 = 78.07 (dB)
(2)PR 的计算
PR = PT / ( 10 7.807 ) = 10 ( W ) / ( 10 7.807 ) = 1 ( μW ) / ( 10 0.807 )
= 1 ( μW ) / 6.412 = 0.156 ( μW ) = 156 ( mμW )
顺便指出,1.9GHz电波在穿透一层砖墙时,大约损失 (10~15) dB




