A PLANAR WIDEBAND TWO-LEVEL SEQUENTIALLY ROTATED ARRAY ANTENNA FOR X-BAND CUBESAT

A planar wideband circularly-polarized (CP) antenna array is designed for an X-band CubeSat. The design is a two-level sequential phase architecture, consisting of a 4 × 4 element array composed of sequentially rotated of 2×2 subarrays. Each subarray consists of sequentially rotated 2×2 antennas using metasurface. These antenna elements are incorporated with a two-level sequentially rotated phase network in order to obtain wideband characteristic and high gain. The final prototype with a size of 100mm × 100mm × 2.032mm yields a measured |S11| < −10 dB bandwidth of 50% (6–10GHz) and measured axial ratio < 3-dB bandwidth of 40.7% (6.45–9.75 GHz). Additionally, the proposed design achieves a good broadside right-hand CP radiation with a peak gain of 17.0 dBic, 3dB gain bandwidth of 20.4% (7.5–9.2 GHz), and radiation efficiency of > 82%. With these features, the proposed antenna can be compatible with any CubeSat standard structure, as well as other small satellites.