Reflectionless Metalens Collimating Multi-OAM Waves for Antenna Gain Enhancement in Wireless Communication

We propose a thin, light-weight reflectionless metalens which collimates OAM beams with the mode numbers $l =\pm 1$ simultaneously for antenna gain enhancement in wireless communication systems. A tri-Iayer metalens is designed at 10 GHz band based on the transmission line theory and implemented on a tri-Iayer dielectric substrate. It is shown by numerical simulations that the unit cell has the reflection coefficient as low as −30 dB at the design frequency. It is also shown experimentally that a set of TX and RX metalenses yields the maximum gain as high as 18.7 dB which is 10.2 dB higher than that with conventional dielectric lenses.