3D printed millimeter-wave beam-steering reflector using dielectric fluids.

A three-dimensional printed beam-steering reflector surface with dielectric fluids as the tuning agent is presented. The reflector is made using ECO-ABS with six rows of 19 parallel channels of square cross-sections. The permittivity of the ECO-ABS was measured at 2.55 with a loss tangent of 0.053. A conductor is placed at the back of the dielectric. The squared channels are filled with either distilled water or air. The effective permittivity within the reflector changes according to the material used to fill the channels. As an incident wave propagates through the printed dielectric, the configuration of air-water channels shapes the exiting phase front of the wave by locally controlling its phase delay. The resulting phase profile created by the air-water configuration leads to a steered beam. Numerical full-wave simulations show steerable angles ranging from -42 to 23° for a set of air-water configurations at 30 GHz. A prototype was fabricated and tested for the same configurations. Experiments confirm a wide range of angles starting at -40 up to 20°.