A High Efficiency and Low Mutual Coupling Four-element Antenna Array for GNSS Applications

Abstract

In this manuscript, a compact four-element antenna array is introduced for global navigation satellite system (GNSS) upper L-band applications. The proposed design is modelled using a higher epsilon substrate to obtain a smaller patch footprint. The array consists of four rectangular right-hand circularly polarized (RHCP) patches etched on a circular substrate having a compact diameter of only 125 mm. The patch elements cover the BeiDou B1 (1561.098 MHz), GPS L1 (1575.42 MHz), Galileo E1 (1575.42 MHz), and GLONASS G1 (1602 MHz) bands with an axial ratio below 3 dB. A defected ground structure (DGS) has been integrated in the ground plane of the proposed array along with a novel meta-isolator on the top side between the antennas to achieve a high isolation level of more than 24 dB in the complete band of interest. The proposed antenna array has a high gain of more than 6.9 dBi and a radiation efficiency greater than 93%. A prototype of the proposed array is fabricated, and measured results are presented to validate the design.