The research proposes an original and efficient two-element based multiple-input multiple-output antenna (MIMO) for ultra-wideband technology. The Orthogonal structure is utilised in the design of the recommended antenna. The addition of the orthogonal structure greatly reduces the mutual interactions between the antenna elements. Furthermore, the use of a ground plane with a trapezoidal form broadens the impedance bandwidth. As a result, the antenna has a low-profile design and measures just 32 mm × 60 mm × 1.6 mm. Additionally, the suggested antenna embeds various slits on the square radiating parts to provide triple band-notched features. The extensive bandwidth of 2.95–11.10 GHz is thus acquired by the antenna along with the frequency notched bands of 3.2–3.9 GHz, 5.2–5.95 GHz, and 8.2–9.75 GHz. The three notched bands correlate well with currently operational WiMAX (3.3–3.7 GHz), WLAN (5.15–5.875 GHz), and lower X-band (8–10 GHz) interference bands. The proposed antenna also exhibits a reduced envelop correlation coefficient (ECC < 0.0466) and a lower mutual coupling (<−15 dB). For wireless communication applications involving MIMO along with UWB, particularly for convenient UWB-MIMO systems, the suggested antenna may therefore be a useful option.