A Method for Simultaneous Control of Beamwidth and Beam Direction in a Cylindrical Metasurface Cloak

In this work, a design method for the cylindrical metasurface cloak capable of simultaneously controlling beamwidth and beam direction is proposed. By precisely tailoring surface waves amplitude distribution along the cylindrical metasurface cloak, both the beamwidth ratio between the incident and outgoing waves and the direction of the outgoing wave can be designed as desired. First, taking a unity beamwidth ratio (1:1) as the design example, an incident Gaussian beam passes through the cylindrical metasurface cloak without reflection, and the outgoing wave maintains the same beamwidth as the incident one, thereby validating the effectiveness of the proposed surface wave coupling based cloak design. Second, to demonstrate beamwidth control capability, cases with beamwidth ratios of 2:1, 1:1.75, and 1:3.5 are successfully implemented. Subsequently, the cylindrical metasurface cloak design enabling directional control of the outgoing wave is presented, in which a horizontally incident Gaussian beam is deflected by the cloak at angles of +20°, –30°, and +50°, respectively. Finally, a cylindrical metasurface cloak design method that allows simultaneous control of both beamwidth and beam direction is established. The required impedance profile of the cylindrical metasurface cloak is realized using subwavelength structural units, and a practical cylindrical metasurface cloak prototype with dual control functionality is designed. Both numerical simulations and experimental measurements further confirm the accuracy of the proposed design method in achieving simultaneous and precise control over beamwidth and beam direction.