Scanning characteristics of spherical dome antenna composed of arcing dipole array antennas including the effects of mutual coupling between elements

Abstract

AbstractFor a beam scanning at high speed over a wide angle, a dome antenna has been proposed. Past research on the dome antenna treated the dome parts as an ideal lens. However, the concrete arrangement of antenna elements outside and inside the dome and their mutual coupling have not been considered. Based on our past work on the electromagnetic field inside a concave spherical surface, this paper describes the results of analysis performed on the most fundamental dome antenna composed of arcing array antennas. For the array elements we considered dipole antennas. We obtained the radiation characteristics considering the mutual coupling among the elements of the radiators on the convex surface, the elements of the collector on the concave surface, and the coupling between the elements of the collector and the elements of the primary radiator. We determined the excitation currents in the elements of the primary radiator so that the currents in the elements of the radiator become co‐phase and uniform amplitude along the direction of the main beam. We obtained the radiation characteristics, and confirmed that over the range from 0 to 110°, beam scanning at almost a constant gain was possible. Next, we suppressed the levels of the sidelobes. We showed that up to a maximum of 18 dB, we suppressed the levels of the sidelobes compared to the co‐phase excitation. Finally, we discussed the influence of the mutual coupling between the elements of the radiator and the elements of the collector on the directivity.