Beam forming network and base station antenna

A beam forming network is provided by the embodiment of the present invention and includes: a first 180 degree bridge for equal power division, a 180 degree bridge for unequal power division, a 90 degree phase shifter, a second 180 degree bridge for equal power division; 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 direct port of the sum input port of the first 180 degree bridge for equal power division is connected to the input port of the 90 degree phase shifter, the 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 direct 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; the coupling port of the sum input port of the 180 degree bridge for unequal power division and the two output ports of the second 180 degree bridge for equal power division are used for feeding the antenna array. The beam forming network with a simple structure is easy to be fabricated.