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 (CP) microstrip patch antenna (MPA) is presented with the assistance of the sub-structure characteristic mode (CM). The MPA consists of two patch layers, which has RHCP radiation patterns around 1.575GHz and 2.492 GHz under port 1, while LHCP radiation pattern is also acquired around 1.615 GHz under port 2. Most importantly, the satisfactory isolation between two ports is guaranteed, indicating that the proposed MPA is an excellent candidate for BeiDou navigation satellite system (BDS).