Dual-Band Dual Circularly Polarized Microstrip Antenna With Two Eccentric Rings and an Arc-Shaped Conducting Strip

In this letter, a novel low-profile dual-band and dual circularly polarized (CP) microstrip antenna is proposed. The antenna consists of two circular eccentric rings (CECRs) with different sizes. The two eccentric rings each work as a single-band circular polarization radiator and are simultaneously excited by an arc-shaped strip. A lumped equivalent circuit model is developed to analyze the operation mechanism of the antenna. In order to simplify the design procedure, empirical formulas are derived based on the physical parameters of the antenna. The proposed structure has been examined by both simulation and experiment, and both results agree very well.