A novel high-isolation dual-polarized air-patch antenna based on composite decoupling structure

This paper presents a novel wideband dual-polarized air-patch antenna with enhanced port isolation. The proposed design consists of a suspended metal patch, two feeding slots, and novel composite decoupling structures (CDS). The CDS is composed of two reactive loads (RLs), an additional square slot (ASS), and two neutralizing lines (NLs). The reactive loads and one NL are connected to the feeding slots. The other NL is connected to the ASS. The CDS plays a critical role in achieving wideband high port isolation. The decoupling principles are illustrated by using a circuit model and through rigorous mathematical derivation. Design evolution of the proposed antenna (Ant 1-5) was carefully explained. Experimental results demonstrate that the proposed antenna has a -15 dB refection coefficient bandwidth covering the frequency range of 3.32-3.67 GHz. Additionally, it exhibits high port isolation (>35 dB), low cross polarization, high gain, and excellent total efficiency (>85%).