A Slot Antenna Array With Low Cross-Polarization Level Based on a Novel Substrate Integrated Coaxial Line Feeding Structure

A slot antenna array with low cross-polarization level based on a novel substrate integrated coaxial line (SICL) feeding structure is proposed in this paper. The longitudinal slots are etched on the top layer as the radiation part, thus a broadside radiation characteristic can be achieved. Two sets of SICL are arranged on both sides to feed the quasi-substrate integrated double line (SIDL), and the length of the quasi-SIDL is adjusted to obtain the optimal slot etching scheme. A slot antenna array covering 27.1-27.6 GHz is designed and verified. The simulated results show that the peak gain is more than 8.6 dBi, while the cross-polarization level is better than 43.9 dB. The excellent radiation performance makes it a strong competitor for millimeter-wave (mm-wave) wireless applications.