A small low-multipath GNSS antenna using annular slot loaded ground plane

A small low-multipath antenna is proposed in this paper for global navigation satellite system (GNSS) applications. An annular slot loaded ground plane (ASLGP) is adopted to reduce the multipath interference of the proposed antenna. The radiation field of the slot can be adjusted to cancel out the backward radiation. A prototype antenna operating at L1 (1.575 GHz) band is fabricated and measured. A front-to-back ration (FBR) over 50 dB and backward cross-polarization level below - 21 dB are achieved with the prototype antenna. Furthermore, the proposed antenna keeps low mass and miniature size.