A Wide-Beam Metasurface Antenna Using Pattern Combination of Characteristic Modes

Abstract

In this paper, a new method based on characteristic mode analysis for designing wide-beam antennas is proposed. According to theory of characteristic modes, the total radiation pattern is the linear combination of modal currents. The phase of the excitation coefficient is demonstrated to be the characteristic angle. To get a wide-beam pattern, a fundamental mode and an even mode are selected to be excited and combined. The method is verified by the proposed antenna. First, two modes are selected based on characteristic mode analysis. Then the modes are excited separately using different feeding networks. Lastly, a 1-to-3 power divider is proposed to combine the feeding networks. The proposed antenna has a 3-dB beamwidth of over 200∘ in both 45∘ and 135∘ planes. The results have shown that the proposed antenna is suitable for a wide range of detection applications.