A Wideband and Circularly Polarized Wide-Angle Scanning Phased Array with Substrate-Integrated Cavity-Backed Patches

A wideband and circularly polarized (CP) substrate integrated cavity-backed patch antenna is proposed. This antenna has a wide-beam radiation pattern. The half power beam-width (HPBW) is 154° and the axial ratio (AR) below 5.8dB is more than 229° in both $\mathbf{phi}=\pmb{0^{\circ}}$ and $\mathbf{phi}=\pmb{90^{\circ}}$ planes, which has a large potential for CP wide-angle scanning phased array. The impedance bandwidth with SII $< \pmb{-10}\mathbf{dB}$ is more than 23%. An $\pmb{8 X 8}$ planar phased array based on the antenna element is designed. The simulated results show that the main beam can scan from -60° to + 60° with 3dB gain fluctuation and from -80° to + 80° with 6.5dB gain fluctuation. Meanwhile, the AR is smaller than 3dB within the scanning range from -60° to + 60°, and smaller than 6dB within scanning range from -80° to + 80°.