Performance comparison between arrays with rotating linear polarization elements and circular polarization elements

In this paper , it is shown that, for large element spacing, a rotating LP elements' array becomes 50% less aperture efficient than a CP elements' array . On the other hand, for small element spacing, the difference in aperture efficiency between the two arrays is negligibly small. Consequently, for small element spacing, the rotating LP elements' array is likely to have more overall efficiency than the CP elements' array because the latter has the additional RF loss due to polarizer circuitry. Furthermore, it is found that in the array environment the return loss bandwidth of an LP elements' array is narrower than that of a CP elements' array. In order to have a complete characterization of the two arrays, we present numerical results based on a full wave Floquet MoM analysis of slot-fed patch elements. Advantages and disadvantages of the two arrays are discussed.