Scalable Omnidirectional Dual-Polarized Antenna Using Cavity and Slot-Dipole Hybrid Structure

This article proposes a scalable dual-polarized antenna using the compact cavity and slot-dipole hybrid structure for omnidirectional radiation. For the horizontal polarization, an open-ended cavity is uniformly excited at its TE
_1/2,0,0
mode to achieve omnidirectional coverage. Based on this thin cavity, a hybrid structure with slots and parasitic dipole stub pairs is designed for vertical polarization, providing an omnidirectional pattern in the azimuthal plane. The measured results show that dual-polarized radiations with port isolation higher than 25 dB and gain variations lower than 2.7 dB are achieved in the band of 2.39–2.49 GHz, covering the frequency band of wireless local area network (WLAN) system. Moreover, to validate the scalability of the proposed antenna, a cascaded array is contrived to realize high-gain omnidirectional radiation. Compared with the existing works, the proposed omnidirectional dual-polarized antenna has the advantages of both compact volume and array scalability, exhibiting promising usage for high-gain router applications.