Dual-Band Circularly-Polarized Shared-Aperture Array for C/X-Band Satellite Communications

Research output: Contribution to journalArticle

Authors

  • Chun-Xu Mao
  • Steven Gao
  • Yi Wang
  • Qing-Xin Chu

Colleges, School and Institutes

Abstract

A novel method of achieving a single-feed circularly polarized (CP) microstrip antenna with both broad impedance bandwidth and axial ratio (AR) bandwidth is presented. The CP characteristics are generated by employing a resonator to excite the two orthogonal modes of the patch via two coupling paths and the required 90° phase difference is achieved by using the different orders of the two paths. The presented method, instead of conventional methods that power dividers and phase delay lines are usually required, not only significantly enhances the bandwidths of the antenna but also results in a compact feed, reduced loss and high gain. Based on this method, a dual-band shared-aperture CP array antenna is implemented for C-/X-band satellite communications. The antenna aperture includes a 2 × 2 array at C-band and a 4 × 4 array at X-band. To accommodate the C-X-band elements into the same aperture while achieving a good isolation between them, the C-band circular patches are etched at the four corners. The measured results agree well with the simulations, showing a wide impedance bandwidth of 21% and 21.2% at C-band and X-band, respectively. The C-band and X-band 3 dB AR bandwidths are 13.2% and 12.8%. The array also exhibits a high aperture efficiency of over 55%, low sidelobe (C-band: -12.5 dB and X-band: -15 dB), and high gain (C-band: 14.5 dBic and X-band: 17.5 dBic).

Details

Original languageEnglish
Pages (from-to)5171-5178
JournalIEEE Transactions on Antennas and Propagation
Volume65
Issue number10
Early online date17 Aug 2017
Publication statusPublished - 1 Oct 2017

Keywords

  • broadband , circularly polarized (CP) , dual band , microstrip antenna , satellite communication , shared aperture