A Dual-Frequency Microstrip Antenna with Wider Beam and Higher Gain at Low-Angle

A dual-frequency circularly polarized microstrip antenna with wider beams and higher gain at low-angle is proposed in this paper, which is fed by a proximity-coupled microstrip-line. The proposed antenna has no 90-degree hybrid coupler for circular polarization and allows easy connection between a microstrip line and an antenna element. The simulated results verify the circular polarization and show that good return loss and axial ratio characteristics have been obtained.