3D Luneburg Lens Antenna With Layered Structure for High-Gain Communication Systems

A novel spherical Luneburg lens antenna is presented providing high efficiency, multiple beams and dual polarization. The lens is constructed of planar layers of light-weight foam with conducting cubic inclusions of different sizes located on an equally spaced three-dimensional (3D) orthogonal grid. This structure makes for simple manufacture of the lens and reduces the cost and weight which have been major problems with Luneburg lenses in the lower frequency microwave bands. A dual +/- 45 degrees -polarized square waveguide is used as the lens source to demonstrate the dual-polarization beam scanning capability of the lens. A prototype lens antenna operating in the 3.3 to 3.8 GHz band has been designed, fabricated and tested. Measured results show that the lens can achieve multiple beams in both planes with a scanning loss of less than 0.8 dB, a peak gain of 23 dBi, and a radiation efficiency of better than 90%.