The present application discloses an array antenna, a method and a device for transmitting and receiving a signal. The array antenna includes at least two active antennas, wherein each active antenna is surrounded by at least two different parasitic antennas, respective parasitic antennas are respectively coupled to controllable loads, and the controllable loads are respectively coupled to a control circuit. With the arrangement of at least two active antennas, when a channel is in a good state, channel capacity can be adjusted by adjusting the controllable loads coupled to the parasitic antennas; and when the channel is not in the good state, the bit error ratio can be reduced by both adjusting the controllable loads coupled to the parasitic antennas and adjusting transmitting directional diagrams of the active antennas according to an adjustment vector, meanwhile, miniaturization can also be realized.