Pattern Reconfigurable Antenna Employing Liquid Metal

This paper presents a novel liquid-metal pattern reconfigurable antenna. The designed antenna applies the Yagi-Uda approach and a switchable ground plane. The antenna consists of a circular driven patch and four circular parasitic patches. Four drill holes are placed beneath the parasitic patches. We can inject or remove Gallium-based liquid metal into the drill holes. This can change the states of the parasitic patches. On the other hand, the switchable ground plane for the antenna consists of three parts. They are a printing copper region and two changeable regions filled with Gallium-based liquid metal. Changing the states of the liquid metal regions in the ground plane can achieve beam switching. The proposed antenna provides three different beam switching directions. They are 0° and ± 68° with ~2 dB of scan loss at 5.9 GHz. The antenna was fabricated and we measured it in the far-field chamber. The measured results have a good matching with the simulated results. In future communication systems, the proposed antenna could be a good candidate.