A Ku/Ka‐Band Broadband Folded Transmitarray Antenna for Satellite Communication Based on Polarization Conversion Units

A Ku / Ka ‐band broadband low‐profile transmitarray for satellite communication is presented in this letter, and it effectively reduces the profile height ( H / D ) to 0.21. This design consists of two types of polarization conversion elements, an integrated low‐profile magneto‐electric dipole feed, and a Ka ‐band horn. The Ka ‐band element can achieve a 360° phase coverage and convert the x ‐polarized waves to transmitted y ‐polarized waves. Moreover, the proposed Ku ‐band element utilizes “receiver‐via‐transmitter” structure and frequency selective surfaces (FSS) to realize the high‐performance polarization conversion capability in both Ku ‐ and Ka ‐bands. Then, a prototype was simulated, fabricated, and measured, which shows high consistency between the measured and simulated results. The prototype achieves the maximum aperture efficiencies of 34.25% and 31.75% in Ku ‐ and Ka ‐bands, respectively. It also achieves the 3‐dB gain bandwidths of 26.45% in Ka ‐band and 38.62% in Ku ‐band, along with a 3‐dB axial ratio bandwidth of 46.67%. The proposed design demonstrates good bidirectional and dual‐band operations, making it promising for satellite communication and radar detection systems.