volume | PIER Journals

Abstract

A compact, fractal-shaped, triple-band multiple-input multiple-output (MIMO) antenna integrated with a frequency-selective surface (FSS) to improve radiation characteristics is presented in this work. The proposed design employs a fractal-based radiating element to achieve multiband characteristics while minimizing the size. The four-port MIMO configuration is developed from a single-port radiator using an orthogonal arrangement to improve the port isolation. A central square slot is introduced to suppress mutual coupling by interrupting surface current paths, thereby improving inter-element isolation across all operating bands. To enhance the gain, a multi-resonant uniplanar frequency selective surface (FSS) is designed and positioned to act as a partially reflective surface. The FSS unit cell, modelled using an equivalent circuit approach, exhibits three distinct stopbands corresponding to the desired operating frequencies of 2.7-3.5 GHz, 5.5-8.4 GHz and 9.3-10.9 GHz. The combined antenna-FSS configuration, with the overall electrical size of (0.5×0.5×0.235)λ, demonstrates a gain improvement of 3-4 dBi in all bands, without compromising bandwidth. With three frequency bands of 2.5-3.875 GHz, 5.25-6.05 GHz and 8.6-10.6 GHz, the proposed MIMO antenna achieves good MIMO characteristics, making it suitable for modern high-speed wireless technologies including sub-6-GHz 5G (WiMAX), WLAN, and ISM bands.

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Dr. Suvro Kundu

Dr. Dheeraj Pandey

Dr. Tej Raj

Dr. Surajit Kundu