Polarization Reconfigurable Magnetoelectric Dipole Antenna with Broadband Stable Gain for Vehicular Satellite Communication System

To provide stable satellite communication quality for vehicles moving at high speeds or in extreme environments, gain robustness antenna represents an innovative solution. A polarization reconfigurable magnetoelectric dipole (ME-dipole) antenna with wide impedance bandwidths, broad 3-dB axial ratio (AR) bandwidths, and stable gain across different polarization states is proposed. To ensure consistent axial directional gain over a wide bandwidth, a design method based on the negative correlation complementarity of directional patterns in frequency variation is proposed. The ME-dipole radiator pair is composed of four rotationally symmetric end shorted patches, where the axial directional gain of the patches and metal vias structures in the ME-dipole exhibits a negative correlation with increasing frequency. Polarization agility is achieved through a reconfigurable feeding network, which utilizes multiple resonances and is implemented using an orthogonal coupling slot loaded with a DC-blocking gap and PIN diodes. When switching between different circular polarization (CP) states, the measured 3-dB AR bandwidths are 34.2% and 37.4% for left-handed circularly polarization (LHCP) and right-handed circularly polarization (RHCP), respectively. In addition to achieving peak gains exceeding 6dBic for both CP senses, the proposed antenna maintains a stable gain fluctuation of no more than 1.3 dB across a broad 31.03% operational bandwidths (1.96-2.74GHz), which is crucial for enhancing the performance of vehicular S-band satellite communication systems.