Research on dual circularly-polarized wideband wide-beam scanning array for low-orbit satellites

With the increasing maturity of satellite communication, the phased array antennas are widely used in lowearth satellite systems. This paper has proposed a new dual circularlypolarized (CP) wideband and widebeam scanning array for loworbit satellite communication. Initially, the array element adopts a metal gridloaded dipole antenna, thus increasing its working bandwidth of about 17GHz~21GHz (21%). Meanwhile, the gridloaded metal contributes to widen the halfpower beamwidths (HPBW) of the element, which simultaneously increases the E-and H-plane HPBW to above 140°. Next, the gridloaded dipoles are employed to form up the 8×8 array. After that, the array element is rotated to realize the double CP performance. Owing to the wideband and wideHPBW of the CP element, the beam scanning angle of the array is effectively expanded to above ±60° in twodimensional. Finally, as the array is working in the lower band of 17GHz, the broadside gain reaches to about 18.2dB. When the scanning angle is about 60°, the gain reduction is only about 2.8dB and the axial ratio keeps of less than 2dB. As the array is working in the higher frequency of 21GHz, the broadside gain is maintained of about 19.6dB. When the scanning angle is about 60°, the gain reduction is about 3.7dB and the axial ratio keeps of less than 3dB. As such, the designed array has the attractive wideband and widebeam scanning performance, thus can be well applied in loworbit satellite communications.