Circularly Polarized Spidron Fractal Slot Antenna Arrays for Broadband Satellite Communications in Ku-band

In this paper, a novel circularly polarized Spidron fractal slot antenna array developed for broadband satellite communication in the Ku-band is discussed. A Spidron fractal slot configuration was utilized as a single radiating element to achieve circularly polarized radiation. The effects of altering the feeding position on the resonance behavior and the radiative characteristics were assessed. As a consequence, the design was expanded from a single element to a 2×2 subarray and further to a 4×4 array in order to enhance the bandwidth performance of the antenna when integrated with a sequential feeding network. Two prototype arrays were fabricated and tested, and measurements revealed that the 2×2 subarray has a 10-dB reflection coefficient bandwidth between 10 and 14.28 GHz, 3 dB axial ratio bands between 10.15 and 11.15 GHz and between 11.75 and 13.92GHz, and a maximum gain of 11.4 dB at 13 GHz. The results for the 4×4 array indicated that both the 10-dB reflection coefficient and 3 dB axial ratio bandwidths cover the entire operating frequency from 10 to 15 GHz in the Ku-band. The maximum gain for the 4×4 array was 15.63 dB at 12.6GHz.