A Dual-Frequency Shared Aperture Wide-Beam Antenna for LEO Satellite Applications

This paper proposes a design method for a dualfrequency shared-aperture wide-beam antenna for LEO satellite communications. The design includes a wide-beam horn antenna operating in the X -band and a wide-beam helical antenna operating in the L-band. These antennas are vertically stacked and nested together through structural reuse to achieve a dualfrequency wide-beam antenna configuration. Simulation results indicate that the S-band antenna achieves $\mathrm{S}_{11}\lt -15 \mathrm{~dB}$ and a gain > -1 dBi within a ± 70° beam range over its operational frequency band, while the X-band antenna achieves $S_{11}\lt -19 \mathrm{~dB}$ and a gain > -2.0 dBi within a ± 70° beam range over its operational frequency band. These results demonstrate excellent circular polarization and wide-beam radiation characteristics of the proposed antenna.