Anti-Jamming GNSS Antenna for Timing Applications

This paper presents a global navigation satellite system (GNSS) circularly polarized ceramic patch antenna using the Yagi-Uda theory to generate a null in the right hand circular (RHC) gain pattern at the horizon and around all azimuth angles to mitigate ground-based interference. The study shows that you can control the nulling elevation angle by changing the spacing of the directors used in this Yagi structure. The optimized results show an important attenuation of the RHC gain at an elevation of 15 degrees. At this elevation the RHC gain is 35 dB down from the max gain which is close to 8 dBic at zenith. The proposed AJ3000 antenna is an efficient and low-cost solution to reduce the impact of intentional and unintentional interference in the higher GNSS band for timing applications.