Implementation of A Flat-Bottom Luneburg Lens Based on Conformal Transformation Optics

Using transformation optics based on numerical conformal mapping, a 2D flat-bottom Luneburg lens is designed and realized using isotropic materials. The gradient-index material profile is discretized and realized through unit cells. Full wave simulation is conducted to verify the performance. Maximum 2D directivity of 14.9 dBi is achieved for a line source when the 2D lens has a free-space electrical size of 10λ. A wide field of view (~ 120 degree) is obtained for a set of planar offset feed points spanning 3.3λ.