Dual-Band Structure Reused Aperture-Sharing Antenna With Low Sidelobe and High Gain for 5G Communication

A dual-band structure reused aperture-sharing antenna is proposed in this letter. The millimeter-wave (mm-Wave) substrate integrated waveguide (SIW) slotted cavity backed antenna array, operating in TE₄₄₀ mode, is embedded into the microwave annular-ring patch antenna, operating in TM₁₂ mode, to share the radiation aperture. Furthermore, the SIW slot antenna radiator is reused as the field regulator for the microwave antenna, effectively canceling out the electric field opposite to the inner annular-ring patch. As a result, the sidelobe caused by the high-order TM₁₂ mode in the annular-ring patch antenna is successfully suppressed. Experimental results show that the operating bandwidth covers the 5G microwave band (3.4–3.6 GHz) and mm-Wave band (26.5–29.5 GHz). The measured gain reaches 10.65 and 18.5 dBi, respectively, while maintaining sidelobe levels below −18 dB. Furthermore, the antenna profile is only 0.012λ₀ (λ₀ is the wavelength in free space at low frequency). Therefore, a compact microwave and mm-Wave dual-band high gain shared-aperture antenna is realized, which provides a promising candidate for 5G communication applications.