Beam forming network and base station antenna

A base station antenna, comprising:

• a beam forming network, comprising:
• a first 180-degree bridge for equal-power division;
• a 180-degree bridge for unequal-power division;
• a 90-degree phase shifter;
• and
• a second 180-degree bridge for equal-power division;
• wherein the first 180-degree bridge for equal-power division, the 180-degree bridge for unequal-power division, and the second 180-degree bridge for equal-power division each have a sum input port, a difference input port, a straight-through port of the sum input port, and a coupling port of the sum input port;
• wherein the coupling port of the sum input port of the first 180-degree bridge for equal-power division is connected to the difference input port of the 180-degree bridge for unequal-power division, the straight-through port of the sum input port of the first 180-degree bridge for equal-power division is connected to an input port of the 90-degree phase shifter, an output port of the 90-degree phase shifter is connected to the difference input port of the second 180-degree bridge for equal-power division, and the straight-through port of the sum input port of the 180-degree bridge for unequal-power division is connected to the sum input port of the second 180-degree bridge for equal-power division;
• and
• wherein two input ports of the first 180-degree bridge for equal-power division and the sum input port of the 180-degree bridge for unequal-power division are configured to receive a signal from a base station transceiver, and the coupling port of the sum input port of the 180-degree bridge for unequal-power division and two output ports of the second 180-degree bridge for equal-power division are configured to feed an antenna array;
• and
• the antenna array, wherein the antenna array comprises multiple linear arrays, each linear array comprises at least one antenna unit, and each output port of the beam forming network feeds one of the linear arrays.