X-band Dual-Polarized Waveguide Filtering Antenna

This paper investigates an X-band dual-polarized waveguide filtering antenna. The filtering antenna is formed by the cascade of a TE
101
/TE
011
mode cavity, two interlaced TE
031
mode cavities and four TE
111
mode cavities. The TE
101
/TE
011
mode cavity has two orthogonal electric fields and is suitable for dual-polarized application with high isolation. The TE
031
mode cavity resonator, which is excited on the center and has symmetrical electric field distribution, is acting as a resonating power divider with equal amplitude and phase output. By 90° rotating and duplicating the TE
031
mode cavity, a cross-shaped cavity is formed. Dual-polarized radiation can be obtained by etching rectangular radiating slot on the top of each TE
111
mode cavity. The measured results show that the dual-polarized antenna has a bandwidth of 4% (9.78-10.18 GHz), a peak gain of 8.5 dBi and a high isolation of 32 dB.