A Compact and Highly Selective Dipole Antenna

A compact and highly selective circularly polarized (CP) filtering antenna based on dipole is proposed in this work. Furthermore, a broadband CP filtering array with high selectivity is implemented utilizing the proposed radiating element. The antenna employs a coaxial single-feed configuration and consists of two substrates, a pair of slotted rectangular dipole arms arranged as crossed dipoles, two phase delay rings to generate a 90° phase shift, four arrowhead-shaped patches, four rectangular strip elements, and a reflector. The slotted dipole arms improve the current distribution and impedance bandwidth, while the parasitic elements improve out-of-band suppression, achieving high selectivity. The reflector further enhances the antenna gain. The simulated results demonstrate that the proposed element achieves an impedance bandwidth of 33.6% (2.38-3.34 GHz) and an axial ratio (AR) bandwidth of 6.4% (2.88-3.07 GHz), while the implemented array exhibits an improved impedance bandwidth of 47.5% (2.02-3.28 GHz) and an AR bandwidth of 43.3% (2.06-3.20 GHz). These features make the proposed antenna a strong candidate for modern wireless communication systems requiring compactness, circular polarization, and filtering functionality.