A Design of S to C band 45° Linear-Polarized Banyan Tree Antenna Array

The stable spatial polarization characteristic (SPC) of wide-band, wide-scanning angle phased antenna array has always been a significant challenge. A 45° linear-polarized Banyan Tree Antenna (BTA) array operated over S to C band is designed in this paper, which covers triple frequency with a maximum scanning of ±45°. The antenna element within an infinite array is designed for VSWR < 2.6 when scanning up to ±45°. Compared to traditional BTA array, we found that the matching structure at feeding position can enhance the active reflection coefficients in the operating bandwidth. An 8×8 designed antenna array was fabricated and measured for verification. The results indicate the BTA array is very good choice for use in wide-band, wide-scanning angle with 45°-linear polarized array.