A Corrugated Half-Circular 4-port MIMO Balanced Antipodal Vivaldi Antenna for Advanced mm-Wave Application

The paper presented a corrugated half-circular 4-port MIMO balanced antipodal Vivaldi antenna (BAVA) on a Teflon (εr = 2.1, tanδ = 0.0002) substrate with a 50 Ω bending feed line that was optimized for millimeter-wave (mm-wave) applications. Corrugations and deliberately placed gaps between antenna elements were included in the design, which considerably improved MIMO performance by enhancing isolation and spatial multiplexing. The results showed a peak gain of 11 dB, an envelope correlation coefficient (ECC) of 0.0002, and isolation below -24 dB, indicating exceptional port separation within the frequency range of 26.6 GHz to 50 GHz. The diversity gain (DG) was 9.998 dB, and the channel capacity loss (CCL) was less than 0.4 bits/s/Hz, indicating strong performance over the frequency range. The total active reflection coefficient (TARC) remained below -10 dB throughout the operational range. Furthermore, mutual coupling was limited, as evidenced by the mean effective gain (MEG) and MEG ratios that were within acceptable bounds. This antenna design represented a big step forward in high-capacity wireless communication systems operating in the millimeter-wave range.