Compact Wideband Antenna with Enhanced Back-Lobe Suppression for Global Navigation Satellite System Applications

This study introduces a compact, wideband circularly polarized (CP) antenna that features back-lobe suppression, customized for global navigation satellite system (GNSS) applications. The antenna design incorporates four rotationally symmetric dielectric blocks utilizing molded interconnect device (MID) technology. Each block supports a T-branch antenna with a spiral element and a parasitic folded monopole antenna, covering the frequency spectra of 1164–1299 MHz and 1525–1614 MHz. The design integrates two mechanisms for back-lobe suppression: the employment of monopole and dipole modes, and the inclusion of a microstrip resonator within a multilayer substrate. Performance assessments reveal that the boresight right-hand CP gain and front-to-back ratio (FTBR) range from −4.2 to 1.4 dBic and 2.1 to 12.9 dB, respectively, for the 1164 to 1299 MHz band, and 2.4 to 3.5 dBic and 8.6 to 17.8 dB, respectively, for the 1525 to 1614 MHz band. Both simulated and measured results confirm the antenna's robust and consistent performance across its operational bandwidth, highlighting its suitability as a compact (53.5 mm×53.5 mm×29.6 mm) solution for GNSS applications.