Design and optimization of low-loss, high-gain metamaterial-based log-periodic dipole array antenna for full Ka-band coverage

This work describes a microstrip log-periodic dipole array (MLPDA) antenna that uses metamaterials and operates across the whole Ka-band. The suggested MLPDA antenna layout provides a wide bandwidth with fewer dipole elements than traditional MLPDA antennas while maintaining the same resonance frequencies. To reduce size while covering a wide operational spectrum, the antenna design includes bending dipoles as radiating elements, as well as an incomplete ground plane. Furthermore, the proposed MLPDA antenna’s energy loss has been reduced while boosting its signal strength (gain) by inserting a metamaterial-based structure in front of it at a certain distance and on the same substrate. The antenna was initially designed using fundamental mathematical equations, then simulated using the finite difference time domain method, and subsequently fabricated and characterized. Additionally, particle swarm optimization (PSO) was used to optimize the design requirements of the metamaterial layer, partial ground, and bending elements. Simulation and experimental results show good agreement, demonstrating that the optimized MLPDAfunctions over a wide bandwidth of 25.9 GHz to 45.2 GHz, with slight variances due to fabrication tolerances and measurement conditions. Moreover, the reduction in energy loss achieved by metamaterials directly leads to the stated 4 dB gain increase across the whole Ka-band, improving efficiency and communication range in a variety of applications, including satellite communications, 5G systems, and radar.