Experimental validation of ultra-thin metalenses for N-beam emissions based on transformation optics

In this letter, we propose an ultra-thin transformation optics metalens to achieve N-beam emissions. Theoretical design is firstly verified by full-wave simulation. Then a four-beam TO metalens antenna is proposed, fabricated and measured to further verify theoretical approach. Compared with the single dipole source, the realized gain of the proposed four-beam antenna is increased by 6 dB, while operational frequency and the bandwidth are kept unchanged.