A transmitter is located 1 OOm from a 28m high brick wall (εr = 4 ), while a receiver is located on the other side, 120m away from the wall. The wall is 20 cm thick and can be regarded as lossless. Let transmit antenna is 20m high and receive antenna is 14m high. The centre frequency is 900 MHz. Considering TE waves, determine the field strength at the receiver caused by transmission through the wall.