Antennas with rotational symmetry - flat and volume self-complementary antennas, consisting of several metallic and slot radiators of identical shapes and dimensions, are considered. Methods of calculating mutual capacitances between individual radiators or groups of radiators, based on conformal transformations and reduction of three-dimensional problems to the planar ones, are presented. Various circuits of connecting the radiators to poles of the generator are examined. Wave impedances of different antennas are calculated. Advantages of analyzing antennas compared with known self-complementary antennas are given.