A mobile wireless communication system operating at 2 GHz utilizes two antennas, one at the base station and the other at the mobile unit, which are separated by 16 kilometers.The

transmitting antenna, at the base station, is circularly-polarized while the receiving antenna, at the mobile station, is linearly polarized. The maximum gain of the transmitting antenna is 20 dB while the gain of the receiving antennas is unknown. The input power to the transmitting antenna is 100 watts and the power received at the receiver, which is connected to the receiving antenna, is 5 nanowatts. Assuming that the two antennas are aligned so that the maximum of one is directed toward the maximum of the other, and also assuming no reflection/mismatch losses at the transmitter or the receiver, what is the maximum gain of the receiving antenna (dimensions and in dB)?