f=3GHz
Pi=500kW
G=1000
Pmin=-90dBm
Lambda= 10 log(x/1mW)
-90=10log(x/1mW)
-9=log(x/1mW)
x/1mW=10^(-9)W
x=10^(-9)*10^(-3)=10^(-12)
Rmax=?
Rmax= pierwiastek 4-stopnia z : 5*10^5*10^6*10*0,1^2/ [10^(10^-(12)*4*pi^3] = 71km
matthas