Circularly Polarized Transmitarray Antenna for CubeSat Intersatellite Links in K-Band

A circularly polarized transmitarray antenna based on aperture-coupled patches is presented for CubeSat intersatellite-link applications in K-band. The concept of aperture coupling simplifies the design of transmitarray elements, as it omits the need for metallized vias. Compared to a five-layer element geometry previously proposed in the literature, the total number of metallic layers is reduced to three metallic layers, as a result of a simple modification in the shape of the crossed coupling slot. The new element has a total profile of 0.13 lambda(0) at 24.6 GHz and exhibits a stable performance over a range of incidence angles. The element is incorporated in a 900-element offset-fed transmitarray antenna. The antenna prototype exhibits a gain of 31.6 dBi with a maximum efficiency of 57% and a 1 dB gain bandwidth of 5.7%. The measured axial ratio is below 0.6 dB across the entire gain bandwidth.