A new triple proximity-fed circularly polarized microstrip antenna

A novel circularly polarized microstrip antenna using triple proximity-fed method is proposed in this paper. The circular polarization radiation is produced by adjusting 120° phase shift between the feeds. In the feeding network, a three-way circular-sector power divider is adopted to distribute the current equally to each feed. A method of moments is employed for optimizing the design and achieving a good circular polarization at the center frequency of 1.28 GHz. The measured result shows that 3-dB axial ratio bandwidth and maximum gain are about 0.68% (8.7 MHz) and 7.11 dBic, respectively, which are consistent with the simulated values of 0.70% (9.0 MHz) and 7.21 dBic. The narrow bandwidth and reasonable gain indicate that this antenna is promising for various applications in L-band.