A Dual-Band Wide Axial-Ratio Beamwidth Circularly-Polarized Antenna with V-Shaped Slot for L2/L5 GNSS Applications

Abstract

This paper proposes a dual-band GNSS antenna featuring a broad axial ratio beamwidth and a straightforward design, optimized for operation in the L2 and L5 GNSS frequency bands. Firstly, an upper rectangular patch, fed by a probe and positioned at a pre-calculated point, is utilized to excite the two orthogonal modes <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$TM_{10}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$TM_{01}$</tex> at L2 and L5 bands. Secondly, a lower stacked V-slotted patch antenna, with an optimized offset shift relative to the upper patch, is employed to fine-tune the operating bands and improve the axial ratio beamwidth (ARBW) at both L2 and L5 bands. Lastly, an irregular slit of optimal size and position is etched in the upper patch to further enhance the ARBW. The proposed antenna shows low reflection coefficient values at 1.17-1.256 GHz for (L2/L5) bands with right-hand circular polarization (RHCP) operation. The ARBWs at two orthogonal cut-planes are <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{250}/\mathbf{203.5}^{\circ}$</tex> and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{231}/ \mathbf{202}^{\circ}$</tex>, with gains of 3.5, and 5.8 dBic at L5, and L2, respectively.