Dual-Sleeves Printed Quadrifilar Helix Antenna With Quad-Band and Ultrawide Beamwidth for Satellite Communication Mobile Terminals
Kunshan Mo, Xing Jiang, Lin Peng, Rui Fang
Abstract
A quad-band printed quadrifilar helix antenna (QB-PQHA) with ultrawide half-power beamwidths (HPBWs) and 3 dB axial ratio beamwidths (ARBWs) for satellite communication applications on the movable platform is proposed in this article. To operate simultaneously at four frequencies and achieve wide bandwidths, the QB-PQHA features two dual-band PQHAs (DB-PQHAs) which are placed coaxially. The inner DB-PQHA is directly fed by the feed network at the bottom via the probes, while the outer DB-PQHA coupling is fed by the branches of the inner DB-PQHA. With optimal spacing between the inner and outer DB-PQHA, the coupling between the radiating branches of the inner and outer DB-PQHA not only enhances the antenna’s impedance matching, but also increases the HPBWs and 3 dB ARBWs. This QB-PQHA has been manufactured and measured, both the measured bandwidths and beamwidths are outstanding and in good agreement with the simulations. The measured four impedance bandwidths are 1.93–2.07 GHz, 2.16–2.4 GHz, 2.44–2.58 GHz, and 2.63–2.70 GHz. The HPBWs at their respective center frequencies exceed 148°, 152°, 158°, and 200°, while the 3 dB ARBWs exceed 144°, 166°, 164°, and 178°, respectively. This novel QB-PQHA is the first to achieve both ultrawide 3 dB ARBWs, HPBWs and exceptional bandwidth at all four frequencies. These outstanding features provide significant advantages for satellite communication terminals on fast-moving platforms, such as ships and vehicles.