Passive Beam-Steering Gravitational Liquid Antennas

We present a new concept to passively steer the antenna radiation beam to a fixed direction by utilizing the liquid fluidity behavior due to gravity. Completely different from existing technologies, the proposed antenna does not require any additional mechanical structures, phase shifting circuitry, liquid pumps, tunable elements, or their associated components. By properly designing the structure and resonant mode of the liquid dielectric resonator, the proposed passive antenna can automatically steer the radiation beam to the fixed and desired direction for communication upon physical reorientation of the antenna. An antenna prototype has been proposed with a fundamental resonant band of 1.4–1.8 GHz by using new liquid materials, while its passive beam-steering feature has been experimentally verified. This simple, elegant, and low-cost antenna has combined the gyroscopic correction, gravity, and beam steering into one for the first time, presenting significant implications for radio communications and radar systems that demand an adaptive antenna beam in certain directions.