Design of cylindrically bent antenna array on LCP substrate with large coverage at 60 GHz

The relative permittivity and homogeneity of LCP material have been characterized within the whole 60 GHz frequency band using the microstrip ring resonator (MRR) method. Using a circuit model, the gap capacitance of the MRR has been taken into account in order to improve the accuracy of the determined relative permittivity. The results show that the relative permittivity of LCP is almost constant (ε_r ≈ 3.1) within the whole 60 GHz frequency band. The homogeneity of LCP is within 1.5% across the LCP panel. A cylindrically bent antenna based on LCP substrate has been designed, which has 56.3-67.0 GHz bandwidth and 6 dBi gain. With the proposed equilateral triangle grid array topology and sub-array switching, the cylindrically bent antenna array with 16 antenna elements has 13.8 dBi gain up to ±60° scan angles.