Design of Meander Line Dual-Circular Polarizers with Finite Aperture

A meander line polarizer coupled with broadband step horn antenna is designed to operate in Ka-band satellite communication systems at 29.5GHz. In contrast to normal circularly polarized antennas, this design enjoys simple feeding mechanism and radiating structure. Supporting foam are used both between the antenna and meander line polarizer, and inside the polarizer to provide stability. Meander lines are etched at the bottom side of dielectric plates so that they are not exposed to air and moisture. During the design, it is found that tradition design methods based on formulas or periodic elements work poorly for such meander line polarizers with finite size. Great CP performance with axial ratio below 2dB is achieved between 29 to 30GHz. No gain or matching degradation caused by the meander line polarizer is observed.