Performance of CRLH-TL-Hilbert Structure Inspired Antenna Loaded with AMC Reflector for Wireless Applications

This study presents a novel reconfigurable antenna design for 5G‑sub6 GHz communication networks, achieving significant gain enhancement and beam‑steering capability through the synergistic integration of a composite right/left‑hand transmission line (CRLH‑TL), a Hilbert‑curve electromagnetic bandgap (EBG) structure, and an artificial magnetic conductor (AMC) reflector. The antenna comprises 17 CRLH TL unit cells coupled to a third-order Hilbert fractal EBG, eliminating conventional via holes and minimizing surface-wave losses. Without the AMC reflector, the antenna achieves a peak gain of 16 dBi at 5.6 GHz. Incorporation of a 7 × 10 hexagonal AMC reflector array exhibiting zero reflection phase enhances forward gain to 20 dBi at 5.6 GHz, representing a 4 dB improvement while suppressing back lobes and producing a unidirectional radiation pattern. Reconfigurability and beam‑scanning are enabled via an optical switching mechanism employing light-dependent resistors (LDRs), achieving gain variation and ±5° beam steering at 5 GHz. The design achieves a 2.1 GHz impedance bandwidth (S11 < -10 dB) and 78% radiation efficiency. Compared to prior CRLH‑TL antennas, this work demonstrates a 4 dB gain improvement and introduces optical reconfigurability without via-based fabrication complexity. Simulation and measurement results exhibit excellent agreement, validating the design methodology. The proposed antenna is suitable for adaptive 5G base stations, satellite communications, and beam-steerable radar systems.