A Triple-Band Miniaturized Circularly Polarized Microstrip Antenna for GNSS Applications

This paper proposes a triple-band miniaturized circularly polarized microstrip antenna operating in the L1, L2, and L5 bands of Global Navigation Satellite System (GNSS). The radiating structure includes two stacked microstrip patches, which are miniaturized by etching slot and using high dielectric constant substrate. The antenna volume is
$\mathbf{30}\mathbf{mm}\times \mathbf{30}\mathbf{mm}\times \mathbf{16}\mathbf{mm} (>\mathbf{0.12}\boldsymbol{\lambda}\times \mathbf{0.12}\boldsymbol{\lambda}\times \mathbf{0.06}\boldsymbol{\lambda},\ \boldsymbol{\lambda}$
is the wavelength at 1176MHz). Circular polarization is generated by using double feedings. A wideband feeding network is designed to provide two-way signals with equal amplitude and 90° phase difference, by combining a Wilkinson power divider and a Schiffman phase shifter. The peak gain of the proposed antenna design achieves 5.5dBiC, 4.8dBiC, and 3.7dBiC at 1575MHz, 1227MHz, and 1176MHz, respectively.