LAUSR

This letter presents a dual‐band dual‐sense circularly polarized (CP) duplex antenna based on magneto‐electric dipole structure. A modified aperture‐coupled feeding structure is developed to excite the LHCP and RHCP antenna modes to realize dual‐band dual‐sense CP operation. Annular slots, U‐shaped slots, and a composite balun structure are added to improve the impedance matching, AR bandwidth, and port‐to‐port isolation. For demonstration, a duplex circularly polarized antenna prototype is implemented and measured. The antenna operates as an LHCP antenna and an RHCP antenna within the lower and upper frequency bands, respectively. The port‐to‐port isolation is more than 22 dB. Above features make the proposed antenna a good candidate for simultaneous transmit and receive (STAR) applications.