A Wideband Crossed Dipole Filtering Antenna With Circular Polarization

This letter presents a broadband circularly polarized filtering antenna with a parasitic square loop and four U‐shaped elements. The antenna incorporates slotted branches on the dipole arms to enhance impedance matching and improve the axial ratio bandwidth for circular polarization (CP). The parasitic square loop creates a radiation null in the low‐frequency range, whereas the use of four U‐shaped parasitic branches improves high‐frequency filtering characteristics. Simulation results reveal the antenna achieves a −10 dB impedance bandwidth of 46.1% (1.67 ~ 2.67 GHz) and a 3 dB axial ratio(AR) bandwidth of 82% (1.32 ~ 3.12 GHz). The antenna also demonstrates significant out‐of‐band suppression, exceeding 16 dB at the lower band and 24.7 dB at the upper band, with a peak gain of 7.88 dBi within the band. The antenna exhibits excellent circular polarization and filtering performance, making it ideally suited for satellite communication applications.