Circularly Polarized Monopulse Antenna Based on Sequential Rotation Array Using Cross-Polarization

In this paper, a novel circularly polarized (CP) monopulse antenna utilizing cross-polarization component is proposed. The CP monopulse antenna is realized by a sequential rotation array (SRA) and a feeding board perpendicular to the normal of the SRA. The SRA employs corrugated Goubau lines for sequentially rotating phase increment, and radiations in two orthogonal circular polarizations separately establish sum and difference patterns. Magnitude and polarities of the orthogonal CP radiations vary when the angle deviated from the boresight increases, leading to the change of the signals at each port. Angular information in both elevation and azimuth directions is obtained by comparing the output signals. The proposed CP monopulse antenna provide a method for direction detection using cross-polarization component and has the potential in radar applications.