A W-band dual-polarization slot array antenna with low sidelobe level

- A 94-GHz dual-polarization low-sidelobe-level slot array antenna is proposed. A 2x2-slot cavity-backed subarray is adopted as the basic unit of the array. A high-isolation orthogonal-mode transducer (OMT) with a simple structure is used to excite the dual-polarization subarray. The realization of a low sidelobe level depends on the amplitude-weighted waveguide feed network. A novel unequal power dividing ratio but equal phase (UPEP) single-ridged waveguide divider is presented for the construction of the vertical polarization (VP) array feed network. A 16x16-slot low-sidelobe-level dual-polarization array antenna is fabricated. The machining difficulties of the W-band array are reduced by using simpler structures. The measured results show that the impedance bandwidth is greater than 7.3 GHz, while the first sidelobe levels are lower than -20.1 dB for both polarization arrays within the operating bandwidth. The measured gain is higher than 30.9 dBi for the two polarization arrays with an antenna efficiency better than 64% .