A CPW THz-MIMO antenna with reduced mutual coupling using Frequency Selective Surface for future wireless applications

In this article, we propose a novel THz-MIMO antenna system for future wireless applications. The performance of THz systems is prominently influenced by the MIMO configuration of the antenna. Increased signal attenuation and bit error rate (BER) are major hurdles to system performance at THz frequencies. MIMO antenna diversity techniques at the RF front end can significantly improve system performance. Toward this aim, this work attempts to develop a new THz-MIMO antenna system for future wireless applications. The proposed antenna uses a modified version of a traditional rectangular patch as the radiating element. The combination of a coplanar waveguide (CPW) feed structure and a modified stair-case radiator with an inverted L-shaped arch achieves excellent impedance matching between the feed line and the radiator, resulting in a broad bandwidth in the THz range. To evaluate the diversity performance of the antenna, both spatial and orthogonal 2-port antenna systems are designed and analyzed. Furthermore, isolation is enhanced by placing a frequency-selective surface (FSS) between the radiators of the proposed 4-port antenna. This design offers dual bandwidth, covering the ranges of 2.3-2.7 THz and 5.5-8.9 THz. The proposed antenna achieves very low mutual coupling (less than -30 dB), an extremely low envelope correlation coefficient (ECC) of 0.00001, and a low channel capacity loss (CCL) of 0.1 bps/Hz.