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To achieve multi‐function integration and independent performance regulation of microwave and millimetre‐wave (mm‐Wave) shared‐aperture antennas, a design method based on embedded structure fusion is proposed. In the Sub‐6G band, a high‐order mode annular‐ring patch antenna is designed. To transform the non‐broadside characteristics, the current distribution of TM31 and TM12 modes is reconstructed by slotting in the centre of the patch. Additionally, the electric field distribution is modified by loading shorting pins to achieve beam broadening. In the 5G mm‐Wave band, a four‐element high‐gain substrate integrated waveguide (SIW) slotted cavity backed antenna array with low‐sidelobe characteristics is obtained using the element interleaving technique. The SIW slotted cavity backed antenna array is integrated into the central area of the annular‐ring patch to achieve aperture‐sharing fusion. Experimental results demonstrate that the antenna operates in the Sub‐6G dual‐band of 2.1–2.2 GHz and 5.2–5.4 GHz, respectively. Furthermore, the widest half‐power beamwidth measured in these two bands is 126° and 140°. In the mm‐Wave band, the operating bandwidth is 26.5–29.5 GHz, with a gain of up to 18.8 dBi. Notably, the performance of different bands does not impact the other, and the measured isolation exceeds 40 dB. Furthermore, the antenna profile is only 0.008 λ0. Therefore, an ultra‐low‐profile microwave and mm‐Wave shared‐aperture antenna with multi‐function integration and independent performance control is realised, which has great potential for application in 5G intelligent connected vehicle communications. [ABSTRACT FROM AUTHOR]

The environmental problems caused by the increase in the storage amount of red mud have seriously restricted the development of China's alumina industry, so it is increasingly important to strengthen the comprehensive utilization of red mud. The recovery of sodium and aluminum from the red mud of an aluminum plant in Yunnan by calcification-carbonization method was studied. The calcified and carbonized red mud was characterized by XRD and SEM-EDS. The results show that the optimum conditions of calcification are reaction temperature of 65 °C reaction time of 36 h, calcium-sodium ratio of 4/1 and liquid-solid mass ratio of 4/1. Under the conditions, the sodium oxide recovery is the highest, 59.94%. The optimum conditions of carbonization are reaction time of 3 h, reaction temperature of 110 °C liquid to solid mass ratio 5/1, carbon dioxide pressure of 1.1 MPa, and the aluminum recovery rate is 16.15%. The hydrated sodium alum inosilicate n the red mud is converted into hydrated garnet during calcification, and sodium is released. Hydrated garnets decompose into Cacao3,Cassio3 and Al(OH)3 during carbonization. The method can provide a new idea for comprehensive recovery and utilization of red mud. [ABSTRACT FROM AUTHOR]

Conventionally, both electrically larger (EL) arrays and sparse arrays offer the advantage of element number reduction but disadvantage of high sidelobe levels. A new scheme of planar EL sparse array antenna based on a genetic algorithm (GA) to achieve low sidelobe with element number reduction is proposed. To begin with, EL sparse array antenna optimisation models based on GA for both linear and planar arrays are analysed. Then, an EL slot antenna element based on a 3 × 3 substrate integrated waveguide cavity is designed. An 8‐element linear EL sparse array antenna is designed and compared with a uniform array antenna, demonstrating a reduction in the maximum sidelobe level (MSLL) by nearly 4.6 dB. After that, a 4 × 8 element planar EL sparse array antenna is fabricated and measured. Compared to an 8 × 16 element planar EL uniform array antenna, the number of antenna elements is reduced by 75%, while the MSLL is reduced by approximately 3 dB. The measured −10 dB impedance bandwidth ranges from 25.3 to 27.8 GHz. At the central frequency, the radiation pattern achieves a peak gain of 29.6 dBi, exhibiting low sidelobe levels below −15.0 dB. [ABSTRACT FROM AUTHOR]