A Wideband Polarization Reconfigurable Antenna Array Based on Mode Combination Method

Abstract

Abstract This paper reports a novel polarization-reconfigurable antenna array based on the theory of mode combination (MC), which can electronically alter its polarization states between left-hand circular polarization (LCP) mode, right-hand circular polarization (RCP) mode, and two combined linear polarization (LP) modes. The array element is adopted as the L-probes fed circularly-polarized antenna reported by Luk et al. [1]. To verify the concept, a prototype of 2×2 antenna array is manufactured and tested. By properly exciting the feeding probes, four polarization modes can be switchable. Measurement results show that the proposed antenna has an overlapped −10 dB impedance bandwidth around 34 % for both CP modes and LP(2) mode, and an overlapped 3 dB axial-ratio bandwidth around 22.0 % of the CP modes. The average realized gains are around 12.4 dB for CP modes and LP(1) mode, which remain stable in the axial-ratio bandwidth.