A Ku-band 8×8 dual-polarized high-gain array with mirror-symmetric hybrid feeding network

A mirror-symmetric hybrid feeding network is proposed in this paper for the design of a dual-polarization high-gain array antenna in Ku-band. The hybrid structure consists of E-plane waveguides and series-feed stripline circuits. Input power is coupled from a simple E-plane waveguide to all stripline branches, which are used to excite the circular waveguide radiators individually. However, for the sake of avoiding long line effect from the series-feed circuits in large array, key issue of equal-phase distribution among radiators should be solved efficiently. Two 8×4 stripline sub-networks are placed in a mirror-symmetric position. Such arrangement could introduce another 180 degree phase difference to compensate the antiphase caused by E-plane T-junction waveguide power divider in the design. In turn, all the radiators could be fed in equal-phase. The hybrid feeding network has been realized on an 8×8 array. Design details of the feeding network and array structure are given. The mirror-symmetric hybrid structure can be considered as a good candidate for dual-polarized large array application.