Design, Simulation, and Construction of a Novel Adjustable Wideband and Multi-Polarized Unit Cell of Reflect-Array Antenna by One or Two Control Bits in X and Ku Bands

The purpose of this paper is to design and simulate a unit cell with wideband and multi-polarization for a reflect-array antenna. The bandwidth of the proposed structure is greater than 70% of X and Ku bands for satellite applications. This structure includes two printed dipoles and an asymmetric arrowhead shape for multiple electric and magnetic resonances. Moreover, for enhancing the bandwidth, a thicker substrate is used by stacking different layers. The full-wave simulation results show good polarization conversion over the frequency range of 8-17 GHz. Depending on the antenna usage, the proposed structure can provide dual or triple polarization switching using one or two control bits. Among the innovations of this structure, compared to previous designs, is the switching capability to support multiple polarizations occurring in a common bandwidth. In other words, the desired frequency range is the same for each switching states. The proposed design has a new and simple geometry. In different switching modes, this design maintains or converts the main polarization of the feed antenna to orthogonal polarization and even circular polarization. Two measurement methods are used that include using OMT (Ortho-Mode Transducer) with waveguide for narrow bandwidth and using feed antenna in anechoic chamber for wide bandwidth. These methods confirm the construction of the proposed unit cell by comparing the simulation and measurement results, which show good agreement.