A Design of Dual-Band Circularly Polarized Microstrip Antenna

In order to meet the increasingly frequent communication requirements between data link networks working in different frequency bands, a design of dual-band circularly polarized microstrip antenna is proposed. Based on the basic form of the microstrip antenna, this antenna has dual-band circularly polarized radiation characteristics by cutting four centrally rotationally symmetrical equal-arm U-shaped slots on the square-cut corner patch. The radiation mechanism and structure of this type of antenna are studied and analyzed using electromagnetic simulation software, and a dual-band circularly polarized antenna with operating at 1.85GHz and 4.24GHz is designed, which radiate left-handed circularly polarized waves in low and high frequency. The impedance bandwidth is 1.83~1.89GHz and 4.17~4.29GHz when S 11 less than -10dB, the gain reaches 5dB at the central low frequency, and reaches 7.1dB at the high frequency, the axial ratios at the two frequency points are both less than 3dB.