用于微波烧结黄土的圆波导缝隙天线设计

A Circular Waveguide Slot Antenna for Microwave Sintering Loess

在土木建筑领域,湿陷性黄土地基受水浸湿后需进行热加固处理,避免地基承载力下降导致工程安全事故的发生。针对该问题,设计了一种工作在2.45 GHz、结构简单、在黄土中匹配效果良好及加热效果良好的圆波导缝隙天线,用于微波烧结湿陷性黄土,并使用多物理场仿真软件COMSOL Multiphysics对烧结效果进行了仿真与分析。结果表明,使用该天线加热半径为45 cm的黄土40h后,黄土的平均温度可达到使湿陷性黄土水分蒸发的100℃,最高温度出现在缝隙周围,由于黄土对电磁波的衰减,距离天线越远加热效果越不明显。此外,通过对黄土介电常数和尺寸的扫参,发现该天线在土体中的S11参数随黄土介电常数和尺寸的变化不大,因此该天线在不同的土壤环境下都能实现良好的匹配和烧结效果。

In the field of civil construction,the collapsible loess foundation needs to be thermally reinforcement after being soaked in water to avoid the occurrence of engineering safety accidents caused by the decrease of foundation bearing capacity.In this paper,a circular waveguide slot antenna with simple structure is designed for microwave sintering of collapsible loess.It works at 2.45 GHz and has a good matching effect and a heating effect in loess.And its sintering effect is simulated and analyzed by using multi-physical simulation software COMSOL Multiphysics.The results show that the average temperature of the collapsible loess can reach 100°C after 40 hours of heating the loess with a radius of 45 cm by using the antenna.The highest temperature occurs around the slot.Due to the attenuation of loess to electromagnetic waves,the heating effect is less obvious as the distance from the antenna is further.In addition,by scanning the permittivity and size of loess,it is found that the S 11 parameter of the antenna in loess has little change with the permittivity and size of loess.So the antenna can achieve good matching and sintering effect in different loess environments.