In principle, an all ceramic GRIN lens can be fabricated from a series of concentric dielectric cylindrical rings with different εr. The design principle is shown in Fig. 8. The design parameters are given in Table III and Table IV. In this work, the dielectric lens is comprised of six discrete concentric cylindrical rings. The outermost ring has the lowest εr of 5.3 (pure LMO), while the centre ring has the highest εr of 24.1 (NBMO-10wt%LMO).