W-band hybrid wood zone plate fishnet metalens

We present here the design, fabrication and numerical as well as experimental results of a low-profile hybrid Wood zone plate fishnet metamaterial lens working at f = 99 GHz. The fishnet metamaterial with effective refractive index close to zero (n = 0.51) acts as an anti-reflecting layer as well as a beam shaper, increasing the overall efficiency while maintaining low profile, low cost and ease of manufacturing. The measurements are in good agreement with simulation results and demonstrate a focal length FL = 22.8 mm (7.5 λ
₀
). In a lens antenna configuration a gain of 16.6 dB was measured at the operation frequency. This lens has a low-cost and compact design, and may find applications in integrated lens antenna systems.