A High-Power Sandwiched Omnidirectional Circularly Polarized Antenna for GNSS Systems

Abstract

This paper presents a small-size, low-profile antenna for anti-attacking systems that work against unmanned GNSS-guided attacking vehicles to protect a vital area. The proposed antenna has the ability to handle, theoretically, a peak power up to 157.7 kW. It has a cylindrical shape with a diameter of 75.4 mm and a height of 12.8 mm on a low-cost FR-4 substrate. This small size allows the integration of the proposed antenna with any portable system that prevents the attacks of GNSS-guided vehicles. The proposed antenna covers the whole GNSS frequency band with a fractional impedance bandwidth of 32.5% (1.16-1.61) GHz and a fractional axial ratio bandwidth of 37.6% (1.1-1.61) GHz utilizing a sandwiched structure. This broadband performance is realized using capacitive feeding. The proposed design maintains circularly polarized radiation over a wide elevation angle of 132º and a 360º azimuth angle which makes the proposed design suitable for GNSS anti-attacking systems.

Investigation on a compact wideband omnidirectional circularly polarized antenna in an indoor propagation channel for 2.4 GHz application

“…Consequently, a large number of omnidirectional CP antennas are reported recently. [5][6][7][8][9][10] The omnidirectional CP characteristics can be realized by using broadband omnidirectional vertically polarized (VP) and horizontally polarized (HP) radiators, 11 three stacked circular layers, 12 a top-loaded cylindrical monopole and a modified circular ground plane with extended curved branches, 13 two symmetrical meandering clues, and a small ground plane. 14 However, the narrow impedance and axial ratio (AR) bandwidth are the main design challenge of the above-mentioned omnidirectional CP antennas.…”