## 4 Conclusions  
This paper has presented a broadband circularly polarized (CP) filtering magnetoelectric (ME) dipole antenna featuring a simple yet effective configuration. The fundamental \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Ref.** & **Size** & **Filtering** & **Imp/ AR.** & **Ave Gain** & **Sup.** & **GSI/RSI** \\  & \(\mathbf{(\lambda_{0}\times\lambda_{0}\times\lambda_{0})}\) & **Methods** & **BW (\%)** & **(dB)** & **(dB)** & **(dB)** \\ \hline
[10] & \(1.11\times 1\times 0.039\) & Filtering phase shifter & 7.10\%/7.09\% & 5.4 & 28.7/ & 0.892/ \\  & & & & & 26.9 & N/A \\ \hline
[11] & \(1.55\times 0.9\times 0.058\) & Filtering phase shifter & 11.40\%/14.29\% & 7.86 & 24.11/ & 0.694/ \\  & & & & & 25.92 & 0.71 \\ \hline
[12] & \(0.97\times 0.97\times 0.07\) & Filtering phase shifter & 21.60\%/23.10\% & 6.5 & 23/ & 0.626/ \\  & & & & & 14 & N/A \\ \hline
[16] & \(0.92\times 0.92\times 0.01\) & Parasitic patch & 4.5\%/5.3\% & 7.5 & 22.5/ & 0.65/ \\  & & & & & 24.5 & N/A \\ \hline
[17] & \(0.52\times 0.52\times 0.06\) & Slot & 15.20\%/8.20\% & 6.8 & 26.8/ & 0.73/ \\  & & & & 28.2 & N/A \\ \hline
[18] & \(0.71\times 0.71\times 0.31\) & Slot & 58.30\%/46.9\% & 7.6 & 13.6/ & 0.855/ \\  & & & & 10.1 & N/A \\ \hline
[19] & \(0.59\times 0.47\times 0.1\) & Parasitic patch + Slot & 17.72\%/9.32\% & 6.3 & 20/ & 0.645/ \\  & & & & 21 & N/A \\ \hline
[20] & \(0.51\times 0.51\times 0.26\) & Shorting pin + Slot & 59.00\%/51.80\% & 7.0 & 18.08/ & 0.934/ \\  & & & & 15.89 & 0.57 \\ \hline
[21] & \(1.53\times 1.53\times 0.19\) & Shorting patch & 15\%/16.40\% & 13.0 & 14/ & 0.821/ \\  & & + Open stub & & & 16 & N/A \\ \hline
[22] & \(0.38\times 0.38\times 0.025\) & Open stub & 7\%/4.5\% & 6 & 26/ & 0.916/ \\  & & & & 20 & 0.44 \\ \hline
[23] & \(0.7\times 0.7\times 0.024\) & Two coupled resonators & 4.70\%/3.20\% & 5.5 & 31/ & 0.804/ \\  & & & & 31 & N/A \\ \hline
[24] & \(0.8\times 0.8\times 0.17\) & Ring structure & 25.80\%/13.20\% & 7.2 & 26.2/ & 0.744/ \\  & & & & 36 & 0.54 \\ \hline
**Pro.** & \(0.96\times 0.55\times 0.17\) &
\begin{tabular}{c} Grid Slot \\ + Open stub \\ \end{tabular} & 66.4\%/31.9\% & 5.5 & 11.5/ & 0.926/ \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Comparison of the proposed and reported CP filtering antennas (\(\lambda_{0}\) is the wavelength at the lowest operating frequency). CP radiation characteristics have been achieved through a pair of orthogonally crossed ME dipoles integrated with a phase delay line. By strategically introducing inverted-L-shaped parasitic elements oriented along the \(-45^{\circ}\) direction, the axial ratio (AR) bandwidth has significantly enhanced to 31.9% (3.32-4.58 GHz). The antenna's high-selectivity bandpass filtering response has been realized through synergistic generation of three radiation nulls: one inherently produced by the ME dipole configuration, another introduced by grid slots etched in the ground plane, and a third created through open-circuited stubs loaded on the microstrip feed line. The experimental results have demonstrated excellent performance metrics, including a measured impedance bandwidth of 66.4% (2.87-5.05 GHz), stable in-band gain of 5.5 dBic, and remarkable out-of-band suppression levels of 11.5 dB and 26.8 dB at the lower and upper stopbands, respectively. The proposed antenna has designed exhibits superior comprehensive performance in both bandwidth and filtering characteristics compared to existing CP filtering antenna solutions, offering a promising approach for integrated RF front-end system design, while future work could explore miniaturization techniques for more compact implementations and investigate the integration of reconfigurable elements to enable tunable filtering characteristics for adaptive wireless systems. Conceptualization: [PERSON] and Z.Z. ; Methodology: Z.J. and M.Z. ; Software: [PERSON] and Z.Z. ; Validation: M.Z. and X.L. ; Formal Analysis: Z.J. and Z.Z. ; Investigation: All Authors; Resources: [PERSON] and M.Z. ; Data Curation: [PERSON] and M.Z. ; Writing--Original Draft: [PERSON] and Z.J.