In this article, a parasitic element structure is proposed to reduce the mutual coupling in a miniaturized microstrip dual-band Multiple-Input Multiple-Output (MIMO) antenna, which resonates at (7.8 GHz) for X-band and at (14.2 GHz) for Ku band applications. The design of the primary antenna consists of two identical radiators placed on a 24×20 mm2 Fr-4 substrate, which are excited by orthogonal microstrip feed lines. In addition, a single complementary split ring resonator (S-CSRR) is used to improve the performance of proposed antenna. Simulation and measurement were used to study the antenna performance, including reflection coefficients, coupling between the two input ports, radiation efficiency and the radiation pattern. The measured results show that the proposed antenna achieves two operating bands with impedance bandwidths (|S11| ≤ -10 dB) of 560 MHz (7.6 to 8.16 GHz) and 600 MHz (13.8 to 14.4 GHz) and mutual coupling (|S12| < -26 dB), which are suitable for X/Ku band applications.
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