A low-profile broadband omnidirectional MIMO antenna with dual-polarization is proposed for 4G LTE applications. It consists of two orthogonally polarized radiating elements with separate ports. The horizontally polarized element consists of four printed arc dipoles, a broadband balun feeding network, four arc parasitical strips and four double L-shaped parasitical strips. It exhibits a 48.9% fractional bandwidth (return loss > 10 dB) from 1.70 GHz to 2.80 GHz with a cross-sectional size less than 100×100 mm2. The vertically polarized element consists of a discone, a round sleeve, and a top-loading ring shorted to the ground-plane with three equally-spaced pins. It provides a 47.3% fractional bandwidth (return loss > 10 dB) from 1.68 to 2.72 GHz with an overall volume less than 84×84×22 mm3. In addition, an isolation of 25 dB is achieved in the overlapping band of two elements and the cross-polarization levels for both radiating elements are lower than 20 dB.
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