This paper presents the design of the ultra-wideband dual-polarized 4×4 MIMO remote control electrical down-tilt (RET) three-beam antennas for wireless communications at the frequency band of 1.69-2.69 GHz. Based on the required specifications such as gain, the range of the electrical down-tilt, the azimuth beam coverage, the cross-over point between beams, the side lobe level, and the grating lobe, ultra-wideband dual-polarized 4×4 MIMO three-beam RET antennas have been designed, implemented, and tested.