Table 4 Performance comparison of proposed metasurface antenna with other antennas in a 2 × 2 MIMO configuration.
Refs | Center-to-center spacing (λ0) | 2 × 2 MIMO size (\({\lambda }_{0}^{3}\)) | Center frequency (GHz) | Bandwidth (%) | Isolation (dB) | Beam split | Beam squint (°) | Complexity | Design method |
|---|---|---|---|---|---|---|---|---|---|
0.73 | 1.46 × 1.46 × 0.09 | 5.5 | 21 | > 26 | No | (2)–(8) | High; using metal pins | Suppressing higher-order modes | |
0.5 | 1.06 × 1.06 × 0.03 | 5.8 | 3.4 | > 32 | No | xy-plane: (− 8)–(− 4) yz-plane: (17)–(28) | Low; modifying the ground plane | Defected ground structure (DGS) | |
1.12 | 2.08 × 2.08 × 0.37 | 26 | 21.1 | > 22 | Yes | (− 30)–(30)* | Medium; using air-gap | Metasurface with circular shaped unit cell placed in back side of the antennas | |
1.47 | 3.72 × 2.60 × 0.63 | 26 | 7.5 | > 35 | Yes | (− 16)–(25) | Medium; using air-gap | A metasurface with Circular Split Ring (CSR) | |
0.71 | 1.87 × 1.87 × 0.04 | 27.5 | 16.3 | > 30 | No | Not reported | Low | A metasurface with a 2 × 2 periodic square metallic plates | |
0.735 | 1.47 × 1.47 × 0.07 | 27.63 | 21.7 | > 27 | No | 0 | Low | Binomial series-fed array with loaded patches | |
0.88 | 2.24 × 2.24 × 0.68 | 28 | 20 | > 30 | Yes | E-plane: (0)–(15) H-plane: (0)–(25) | Medium; using air-gap | Partially Reflective Surface (PRS) | |
This work | 0.9 | 1.8 × 1.8 × 0.08 | 27 | 29.6 | > 21 | No | 0 | Low | Manipulating the surface currents of the modes |
