Dual-band circularly polarized transmit-array unit-cell at X and K bands

This paper presents a novel design and analysis on a dual-band circularly-polarized transmit-array unit-cell based on miniaturized elements. The proposed structure is a two dimensionally anisotropic structure composed of capacitive patches, inductive split rings, and an inductive grid. The structure is designed to respond differently to each orthogonal component of a circular polarized wave illuminating the transmit-array and transmits a circularly polarized plane wave. The proposed structure operates at 10.8 GHz and 16.7 GHz with transmission coefficients above -1 dB at both. The simulated and measured results of the unit-cell prototype agree well.