An Improved Sierpinski Fractal MIMO Array Antenna with Enhanced Isolation for Next Generation Wireless Applications

In this article, a modified design of a four port microstrip patch antenna array with dual band is presented. Sierpinski carpet fractal geometry is applied here making the proposed antenna array suitable for the next generation MIMO applications. This antenna structure is designed using FR-4 substrate having a relative permittivity of value 4.4 and microstrip feed line technique is used for antenna excitation. After the application of fractal, by placing the array elements efficiently and by optimizing its inter element spacing (D), improved isolation is achieved here. All antenna structure and its array proposed here are designed using ANSYS HFSS. To demonstrate the effectiveness of the fractal geometry on MIMO antenna, all the antenna performance results like return loss, isolation, VSWR, bandwidth, and gain are analyzed. Improved impendance bandwidth and better isolation factor are challenges in the field of MIMO array antenna design. Simulation result illustrates that, this antenna structure resonates at 6.16 GHz and 15.3 GHz with significant impedance bandwidth values of 62.90% and 46.99% respectively. With the improved isolation factor, and a gain of 5 dB to 10 dB over the entire frequency bands, this fractal MIMO array finds suitable applications in different ongoing (2G, 3G and 4G) and upcoming next generation(5G) wireless communications.