Two stations, located on mountain tops 40 km apart, communicate with each other using two identical paraboloidal antennas with pencil beam- width of 1°, aperture ef?ciency of 0.8, and radiation ef?ciency of 0.85. The transmitting station has Pt = 60Wand Lt = 2 at 8 GHz.With Lr = 1.5 and Lch = 2.5, find the diameter of the antennas and the signal power available at the receiver input.