Orbital angular momentum (OAM) based on uniform circular array (UCA) has been proposed to achieve larger channel capacity in radio frequency. There have been many researches on theoretical analysis and practical antenna design of UCA. However, there have been few studies on the characteristics of OAM signal based on UCA considering spin angular momentum. In this paper, we have proposed two UCA architectures with vertical and circularly rotational polarization configurations to analyze the characteristics of the OAM signal according to the spin angular momentum which the antenna elements possess. We have verified the performances of the UCAs with various antenna element configurations by comparing the channel capacities.