Design an antenna for a transmitter such that 100mW output at 2.4GHz will produce at least 138µW/m^2 at a receiver on a mountain 40 km away. Checking the contour maps shows that you have a line-of-sight path.
a)What gain over isotropic are you designing for?
b)If the transmitting antenna is a parabolic dish, what would be the diameter of the dish, assuming that the effective aperture area is 0.6 times the actual area?