A Circular Polarized Endfire Leaky-Wave Antenna Based on Offset Double-Sided Parallel Strip Lines

This paper presents a novel design for an endfire leaky-wave antenna with high gain and circular polarized (CP) radiation. By etching a series of slots and metal pins on the offset double-sided parallel strip lines, the slots and the edges of the strip line can provide two fields with a 90° phase difference for CP radiation. Meanwhile, the Hanson-Woodyard condition is also met to realize the endfire radiation. To verify our conclusion, an antenna prototype is designed and simulated, the results show that the endfire antenna provides a maximum gain of 12.2 dBi and the maximum radiation efficiency is 90%. Furthermore, CP radiation capability is also validated through the axial ratio.