A Low-Profile Dual-Polarized Patch Antenna With Simple Feed and Multiple Decoupling Techniques

A low-profile dual-polarized patch antenna with simple feed and multiple decoupling techniques is proposed. The proposed antenna consists of two substrates separated by 5 mm. At the top and bottom of Sub 1 are a microstrip balun (Port 2), and a rectangle patch etched with two symmetrical small rectangular slots. A rectangular slot, etched on the metal reflector of Sub 2, is excited by a microstrip line (Port 1). Multiple decoupling techniques are synthesized to achieve high port-to-port isolation, including physical isolation, the shorting pins grounding, orthogonal polarization, and different radiation modes. In particular, the designed antenna has a low profile without any complex feed structure, and the simulated isolation achieves better than 52 dB. Furthermore, its profile is only 0.08 λ0, where λ0is the free-space wavelength at 3.55 GHz, and the measured isolation achieves 45 dB in the working bandwidth of 3.3–3.8 GHz.The fabricated prototype is a promising candidate for the 5G New Radio band n78 communication systems.