Broadband circularly polarized microstrip antenna using single chip-resistor loading

A design of broadband circularly polarized (CP) microstrip antenna with a truncated-corner patch is presented in this paper. Using a single chip-resistor loading at the axis-line orthogonal to the feed location line, the truncated-corner microstrip antenna exhibits an effective axial ratio (AR) bandwidth of 3.0%, which is about three times of that without any chip-resistor loading. The proposed CP antenna is fabricated and experimentally validated.