The major demands of a current wireless communication system are high data rate and channel capacity. Compact multiple-input multiple-output (MIMO) antenna design is the preferable way to handle this issue since MIMO antenna technique can greatly enhance the channel capacity and data transmission speed. Hence, for the ultra wideband (UWB) applications the designs of two compact MIMO antennas are proposed in this article. First, compact MIMO hexagonal antennas are made up of a narrow hexagonal slot on the ground plane and two open L-shaped slot (LS) antenna elements. The first antenna, which is 36 mm × 40 mm × 1.6 mm in size, is etched onto a FR4 substrate. Second, a compact MIMO open scissors (OS) shaped antenna and a multiple truncated ground plane. The elements of the antenna are positioned parallel to one another. Micro strip antennas are popularly used due to their compact size, conformal shape, and cost-effectiveness in manufacturing through printed-circuit technology. An FR4 substrate with dimensions of 21.5 mm × 26 mm × 1.6 mm is used to carve the proposed antenna. MIMO effectively improves a receiver's ability to receive signals by allowing an antenna to add signals of different paths and times. The proposed design is able to provide good isolation, a low correlation coefficient, and stable gains across the entire UWB frequency range, making it suitable for MIMO applications in UWB systems.