Dual-band Circularly Polarized Four-arm Spidron Fractal Antenna for Ku-band Satellite Communication

A dual-band circularly polarized four-arm Spidron fractal antenna is proposed for Ku-band satellite communication. The dual-band characteristic is realized using two-crossed dipole antennas of different lengths. Each dipole arm includes a Spidron fractal patch to generate circular polarization and a printed meander-line to reduce the size. The proposed antenna is fed by a 50-Ω coaxial cable, and a conducting cavity is utilized to obtain a directional circularly polarized radiation pattern. The experiments demonstrate that the fabricated antenna exhibits −10 dB reflection bandwidths ranging from 10.75 GHz to 12.65 GHz and from 13.33 GHz to more than 15 GHz with a broad 3 dB axial ratio bandwidth covering a frequency range of 10.66–14.46 GHz. The measured peak gains are 8.76 dBic in the lower band and 7.43 dBic in the upper band.