A Differentially Fed Dual-Polarized Magnetic Dipole Antenna for Spaceborne Applications

作者：Ren, Xue; Liao, Shaowei; Xue, Quan^*

来源：IEEE Transactions on Antennas and Propagation, 2019, 67(2): 861-871.

DOI：10.1109/TAP.2018.2883526

• Differentially fed
• dual polarization
• magnetic dipole
• platform independence
• stable radiation pattern

This paper presents a novel differentially fed dual-polarized magnetic dipole antenna with stable radiation pattern, platform independence, wide bandwidth, and robust structure for spaceborne applications. The proposed antenna is formed by a dual-polarized magnetic dipole backed by a specially designed rectangular cavity. The magnetic dipole consists of two perpendicular parallel-plate waveguides with stepped edges to broaden the impedance bandwidth, providing good structural reliability which is critical to spaceborne antennas. A cross-shaped conductor fed by two pairs of capacity coupling feeding probes is utilized to drive the dual-polarized magnetic dipole antenna. The specially designed rectangular cavity has four metal plates in four corners to shape the radiation pattern at E- and H-planes. Furthermore, thanks to the cavity, the size of the conducting platform that the antenna mounted on has limited impact on antenna's electrical performances, particularly the radiation pattern. A prototype is fabricated and tested. Measured results show that the antenna achieves a fractional bandwidth of 18.5% with -10 dB reflection coefficient. The realized gain is about 8.5 dBi. A stable radiation pattern with a 3 dB beamwidth of 70 degrees +/- 3 degrees and -4 dBi maximum beamwidth of 152 degrees is observed. The measured cross-polarization is lower than -20 dB within +/- 65 degrees. Measured results are in good agreement with simulation ones.

• 出版日期2019-2
• 单位华南理工大学