Abstract: Compared with the traditional manufacturing process,the processing is simpler, the cost is lower and the precision is higher when the Luneburg lens reflector is made by 3D printing. In this paper, a compact Ku-band Luneburg lens reflector composed of metamaterial-based unit cells has been designed, simulated and characterized. By adjusting the dimension of the unit cell, almost continuously varying gradient index can be achieved. The effective permittivity of the unit cell is calculated by the simulation software CST MICROWAVE STUDIO and evaluated by the effective medium theory. The simulation results show that the proposed Luneburg lens reflector is capable of providing a RCS of -1.49 dBm² with a diameter of 75mm (4l0 at 16GHz), and a sound wide angle response as well.