A low loss 3D Linear-to-Circular polarization converter based on meander-line

A new structure of 3D linear-to-circular polarization converter based on stepped multi-layer meander-line is proposed in this article. Compared with the traditional multi-layer meander-line polarization converters which usually adopt many layers of dielectric plates to form a sandwich structure, the new structure presents not only better performance, such as insertion loss, return loss, axial ratio and bandwidth, but also more stable mechanical strength. A sample working for K-band satellite application was designed. The simulation results exhibited that the operating frequency band covered from 18 GHz to 20.5 GHz, the return loss is less than -15 dB, insertion loss is less than 0.3 dB, and the axial ratio is less than 2.5 dB.