b) Does a K value less than 1 refract a radio beam towards the earth or away from the earth? . Does a K value less than 1 allow greater spacing between towers or require smaller spacing? Does rainfall attenuation increase with frequency? Give three causes of fading. A 4 GHz link spans 30 km. The required signal at the receiver for 99% path reliability is-90 dBW. The available transmitter power is +10 dBW. 30 km. B K What are the minimum gains required for the transmitter antenna and the receiver antenna to fulfill the requirement? Assuming flat terrain with no trees between repeater A and repeater B, and assuming normal refraction, calculate the height required at each repeater for its antenna.