High-Efficiency Air-Filled Wideband ±45° Dual-Polarized Slot Array Antenna

Abstract

This communication presents a wideband ±45° dual-polarized slot array antenna based on full metal structure. Two sets of ±45°-tilted radiating slots are in staggered arrangement, which shifts the polarization plane to the low sidelobe plane. This achieves low sidelobe levels (SLLs) in E- and H-planes for both polarizations. The radiating slots in a row for each polarization are further combined, forming a long slot to obtain stable radiation performance over a wide frequency range. Two compact full-corporate feeding networks based on the double-ridge waveguide (DRW) and the square coaxial line (SCL) are employed to excite the radiating slots of respective polarizations. A prototype of ±45° dual-polarized 8×8 slot array operating at Ku-band is implemented for demonstration. Experimental results show that the antenna is free from grating lobes and exhibits stable, consistent radiation patterns for the two polarizations over the frequency range of 11-15 GHz. Moreover, the SLLs are less than -25.2 dB and the antenna efficiency is over 79.4% across the same frequency band.