Design of a Dual-Fed Triple-Band Circularly Polarized Microstrip Patch Antenna Using Substructure Characteristic Mode

In this letter, a novel design approach to achieve triple-band, dual-port, dual-sense circularly polarized microstrip patch antenna (MPA) is presented with the assistance of the substructure characteristic mode. The MPA consists of two patch layers, which have right-hand circularly polarized (RHCP_ radiation patterns around 1.575 GHz and 2.492 GHz under port 1, while the left-hand CP (LHCP) radiation pattern is also acquired around 1.615 GHz under port 2. Most importantly, the satisfactory isolation between the two ports is guaranteed, indicating that the proposed MPA is an excellent candidate for the BeiDou navigation satellite system (BDS).