An Ultra-Wideband Circularly Polarized Crossed-Dipole Antenna with Band-Notch Characteristic

A wideband circularly polarized antenna operating over frequency range of 1.61-6.18GHz with band-notch performance for 3.58-3.75GHz is presented. The antenna is composed of two orthogonally placed elliptical dipoles printed on both sides of a substrate above a square cavity, which is fed by a coaxial cable and two ring-shaped phase delay lines that introduce a 90°phase difference between the adjacent elliptical arms on the same side. For achieving a band-notch characteristic, four slot-type spilt ring resonators (SRR) have been etched on each of the arms. The bandwidth and central frequency of the notched band can be adjusted by modifying the size of SRRs. Characteristics of the presented antenna have been investigated in terms of the impedance bandwith, AR bandwith, realized gain and radiation pattern. The simulated results confirm that the proposed antenna has good performance for Ultra-Wideband applications.