A Full-SIW Sequential-Rotation Feeding Network Based Ku-Band Wideband Circularly Polarized Array

A wideband high-efficiency circularly polarized (CP) antenna array is presented in this paper. With the specially designed broadband CP element and wideband full-SIW sequential rotation (SQR) feeding network, wideband high efficiency CP radiation can be achieved for the proposed array. For the proposed element, wideband CP radiation is obtained by loading an inhomogeneous superstrate in front of an SIW excited log periodic dipole array (LPDA). Then, a 2×2 array is designed based the wideband CP element and a simplified full-SIW SQR network is also introduced. In order to achieve a full-SIW array feeding, a wideband hybrid mode SIW feeding cavity is also proposed. Besides, by exploring the symmetric property of the LPDA dipole element for 180° phase shift, the SQR feeding configuration is further simplified. With the proposed array design method, simple structure as well as excellent array performance such as wideband CP operation, high-efficiency and wide gain bandwidth are achieved at the same time.