This work presents and analyzes the two/eight-port MIMO antenna operating in dual-band applications. Band 1 is used for LTE B41, whereas band 2 is for WLAN, downlink defense, Wi-Fi 6E (n96), and C-band. The two-port MIMO antenna is built around diamond-shaped with partially ground-plane on jeans substrate. primarily the antennas are placed side-by-side, to enhance to isolation more than 22 dB a T and I-shaped slots are being carved into the ground. The two-port MIMO antenna's total dimensions are 20 × 34.5 × 1.5 mm3. The first band impedance bandwidth is 2.41–2.97 GHz (20.81%), while the second band impedance bandwidth is 4.22–8.33 GHz (65.5%). The minimum and maximum isolation of Band 1 and Band 2 are 20 dB, more than 23 dB, respectively. The recommended dual-band eight-port MIIMO antenna is made up of four two-port MIMO antennas that are positioned orthogonally to create better isolation (>22 dB) between ports. For entire operating bands, the radiation efficiency is more than 65% and the peak gain of the proposed eight-port antenna is 3.5 dB at 8 GHz. The volume of the eight-port MIMO antenna is 4140 mm3. The antenna provides excellent MIMO diversity performance, as evaluated by metrics such as Envelope Correlation Coefficient (ECC < 0.01), Diversity Gain (DG > 9.98 dB), Mean Effective Gain (MEG < −6 dB), Channel Capacity Loss (CCL < 0.03 bits/s/Hz), and Total Active Reflection Coefficient (TARC < −10 dB). Because of its outstanding MIMO diversity performance, the antenna is a promising solution for a wide range of handheld wireless applications.