A Compact Meandered Ring Antenna Loaded With Parasitic Patches and a Slotted Ground for Global Navigation Satellite Systems

A compact meandered ring patch antenna loaded with four parasitic-grounded patches and a slotted ground is proposed. It has two orthogonal T-shaped coupling line feeds with different lengths which produce circularly polarized radiation. The ground is developed with an inner square patch with four symmetric slant corner cuts and an outer ring that further reduces the overall size of the proposed antenna. The measured frequency band with $\vert S_{11}\vert dB, the axial ratio (AR) band with AR $0.169 \times 0.169\,\,\lambda _{\mathrm {g}}^{2}$ and the overall size of the proposed antenna is $0.285\,\,\lambda _{\mathrm {g}}\times 0.285\,\,\lambda _{\mathrm {g}}\times 0.035\,\,\lambda _{\mathrm {g}}$ ( $\lambda _{\mathrm {g}}$ denotes the guide wavelength at the center frequency). The proposed antenna is smaller than the existing antennas and can be an ideal compact antenna used for global navigation satellite system applications.