A compact coupling-fed omnidirectional wideband filtering antenna with high selectivity

This paper presents a compact coupling-fed omnidirectional wideband filtering antenna with high selectivity for modern wireless communication systems. The antenna integrates a coupling-fed driven patch with a symmetrical printed & Gcy;-shaped dipole, facilitating wideband performance and high selectivity through multiple coupling paths. Coupling-fed structure introduces radiation nulls (RNs), achieving an operating bandwidth of 54.5% for |S11| <= -10 dB and out-of-band suppression of -9 dB without requiring additional circuits. Simulations and experiments validate the antenna's performance, demonstrating multiple resonant frequencies and consistent omnidirectional radiation patterns. Compared to traditional designs, it offers superior bandwidth and selectivity, making it suitable for integration into planar RF circuits in applications such as Wi-Fi 6, 5 G, and radar systems.