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.