Genus hologram antenna for MIMO applications

A novel high-gain Genus Hologram Antenna (GHA) based on surface impedance modulation using a periodic array of hexagonal patches is proposed for MIMO applications. The antenna features a simple, low-profile, low-cost structure that eliminates the need for complex feeding networks while achieving frequency-dependent beam scanning, multi-beam generation, and high radiation efficiency. The proposed GHA demonstrates wide-angle beam scanning from 30° to 64° over the frequency band of 13-17 GHz, with a peak gain of 20.6 dBi and radiation efficiency of 87%. By controlling the lattice periodicity of the hexagonal patches, dual-beam radiation at (30°, 40°) and (60°, - 60°), as well as four-beam operation at (120°, 60°, - 60°, - 120°) with a gain of 15.2 dBi at 16 GHz, are successfully realized. For MIMO applications, two GHA elements are integrated with an extremely compact edge-to-edge spacing of only 4.7 mm (0.25λ₀ at 16 GHz). By strategically inserting parasitic elements between the radiating units, the mutual coupling is significantly reduced from - 10 dB to below - 20 dB across the entire operating band, while maintaining excellent diversity performance (ECC < 0.003 and DG ≈ 10). Additionally, the conformal performance of the GHA is investigated on curved surfaces in both transverse and longitudinal directions, confirming its suitability for integration on platforms such as missiles, vehicles, aircraft, and trains. The proposed Genus Hologram Antenna offers a compelling combination of high gain, wide beam-scanning range, multi-beam capability, excellent MIMO isolation, and conformality, making it a strong candidate for modern 5G/6G wireless systems and compact high-performance platforms.