Application: Receive-transmit system. To evaluate the properties of an antenna, two identical antennas are used in a receive-transmit system. The two antennas are placed a distance d = 10 km apart and one antenna transmits 10 W at 300 MHz. The second antenna receives 10 μW. The two antennas are adjusted so that the direction of maximum directivity coincides with the line connecting them. Calculate:
(a) The maximum directivity of the antenna.
(b) The maximum effective area of the antenna.