In this paper, the authors fabri cated and tested the Fresnel Zone lens (FZL)
using subtractive manufacturing (CNC machining) at 5.8 GHz. The FZL is machined from the low dielectric loss polymer, i.e., Polypropy lene (PP) (ϵr = 2.2, tanδ = 1.39 × 10−3 ±2×10−4) having an overall diameter of 307.58 mm (5.94 λ where λ = 51.72 mm). The focal point is 80 cm from the aperture of the conical horn
antenna. A total of 8 subzones (P = 8) for the single full zone (N = 1) is used taking into consideration the optimal size and fabrication facility. A 4 × 4 patch array is used on the receiver side to measure the received power.
The measurements are done at 2 m from the
horn antenna aperture which is in the Fresnel
zone of the Horn+FZL. An improvement of 5.6
dB in the received power is achieved with this
arrangement. The use of CNC manufacturing
is advantageous for the design of FZL with
higher overall dimensions due to single block
manufacturing and the homogeneous ϵr and
tanδ across the FZL.