Continuous Beam Steering Realized by Tunable Ground in a Patch Antenna

Abstract

A continuously steerable patch antenna employing liquid metal is presented. The proposed antenna employs a novel tunable ground plane together with parasitic steering to steer the direction of the main beam. The tunable ground plane consists of a permanent region, made from copper, and two tunable regions formed from liquid metal. The liquid metal channels were fabricated using 3D printing technology. By continuously injecting liquid metal into channels, the proposed patch antenna can provide continuous beam steering from-30° to +30° in the elevation plane, while achieving low side lobe level performance combined with low scan loss performance. Such an approach has never been tried before and it is only possible due to the unique properties of liquid metal. To the best of the authors' knowledge, this is the first time that tunable ground plane has been used for a patch antenna to achieve continuous beam steering. The proposed antenna operates at 5.3 GHz. The antenna is fabricated and measured. Measurement results agree well with the simulation results and validate the effectiveness of the proposed beam steering technique. The proposed antenna has a measured gain of 8.1 dBi at 5.3 GHz and wide bandwidth performance. The tunable ground technique proposed in this work will find numerous applications within future wireless communications systems.