Design and Development of CP Antenna for GNSS Applications

Abstract

The increase in Global Navigation Satellite Systems (GNSS) satellites and services is opening new horizon in satellite navigation. Dielectric resonator antenna (DRA) is widely used in designing antennas where high efficiency is required. DRA provides several key advantages over microstrip patch antenna in terms of losses which becomes significant at millimeter wave frequencies. Various design approach to achieve circular polarization are present in literature whereas challenge to achieve results using simplified feed structure as well as to maintain axial ratio over desired band is a challenging task. This work shows designing and testing of dielectric resonator antenna (DRA) for the application of GNSS using simplified feed and DRA shape. The antenna covers complete bands of (Global Positioning Systems) GPS and GNSS having characteristics of right-hand circular polarization (RHCP). A simplified structure of single feed is used to generate circular polarization and it is fabricated on Rogers 5880 material (𝜀𝑟 = 2.2) with slots on upper side. The antenna radiates by placing DRA material TMM10i (𝜀𝑟 = 9.9) above feedline slots. The proposed antenna has -10dB impedance and axial ratio bandwidth in complete GNSS band (1164 MHz – 1300 MHz & 1559 MHz- 1610 MHz) with simulated radiation efficiency of 95%. The modes excited in the DRA are 𝑇𝐸111and 𝑇𝐸113 in both bands respectively. Complete process cycle including designing, fabrication and testing are mentioned in the work. Fabrication intolerance along with effect of airgap between DRA and feed structure is also discussed. A detailed comparison with other GNSS antenna is also performed to discuss state of the art designs. The filtering of antenna radiation between 1.30 and 1.5 GHz is desired and achieved to reject in-band interference from L-band satellite and terrestrial communication signals. Complete design is tested on real-time system that requires GNSS antenna to compute longitude and latitude. Available data was analyzed on two separate platforms that gave exact location along of tracking satellites