A Dual-Polarized Wideband Ceiling-Mount Antenna With Low Gain Variations and High Isolation for 5G Sub-6 GHz Applications

A dual-polarized wideband omnidirectional ceiling antenna with low gain variations (GVs) for 2G/3G/LTE/5G sub-6 GHz indoor applications is presented. The vertical-polarized (VP) antenna element that is arranged in the center is composed of a pair of orthogonal semicircular plates and a top-loaded circular brass disk, whereas the horizontal-polarized (HP) antenna element is comprised of four printed dipoles with truncated corners, four arc-shaped parasitic patches around the dipoles, and a 1-to-4 power divider feeding network on the bottom. The feeding network with the “hook”-shaped stubs cooperates with the slot between the adjacent printed dipoles to improve the isolation between the VP and HP antenna elements. Furthermore, the top-loaded circular brass disk, the four arc-shaped parasitic patches, and two pairs of extended strips printed along the ±45° direction are used to reduce the GVs but broaden the operating bandwidths. Experimental results demonstrate that a wide overlapped frequency bandwidth of 74.9% (1.66–3.65 GHz) with an excellent port isolation (≥40 dB) is achieved for the aforesaid application scenarios.