A multi-band conformai antenna array for GNSS applications

The position accuracy in satellite navigation is enhanced when low elevation satellites are included in the triangulation due to the contribution of satellite geometry. Moreover, improved reception of low elevation signals leads to a higher overall system availability. However, the receiving antenna characteristics usually suffer from low-gain and high axial ratios at low elevations. In this contribution, an antenna array conformal to a spherical cap is presented. The array consists of a single antenna on top of the cap and six, radially directed, equally spaced elements on a ring. The manufactured antenna achieves a gain between 0 dB and 4 dB with low axial ratio in the forward hemisphere at the E5a/b and E1 center frequencies of 1.176 GHz, 1.207 GHz and 1.575 GHz, respectively.