In this study, the problem of backward heating in microwave ablation technique is examined and an electromagnetic solution based on the use of high impedance graphene material is presented for its mitigation. In this context, a one-atom-thick graphene layer is added on the coaxial double slot antenna. In addition to the electromagnetic behavior, thermal effects caused by the graphene-covered antenna are emphasized. The graphene's conductivity being highly dependent on its chemical potential and the relaxation time, a parametric study is performed to determine a range of tolerances within which the graphene-coated antenna outperform a typical graphene-free antenna. The range of values is found to be 0 < μc < 0.5 eV and τ < 0.4 ps, for the chemical potential and the relaxation time, respectively. The backward heating problem being prevented, the ablation region is ensured to be spherical around the tip of the antenna. Effects of the graphene layer to the heat dissipation in the tissue, the necrotic tissue ratio (damage to the cancerous tissue of the caused by electromagnetic energy), and the treatment time using the coaxial double slot antenna were examined. The results show that the heat dissipation is concentrated around the slots (region of cancerous tissue) and a higher necrotic tissue ratio can be achieved with a graphene-covered double slot antenna in a shorter time.

中文翻译：

---

用于微波消融的基于石墨烯的微波同轴天线：热分析

在这项研究中，研究了微波消融技术中的反向加热问题，并提出了一种基于使用高阻抗石墨烯材料的电磁解决方案来缓解该问题。在这种情况下，在同轴双缝隙天线上添加了一个原子厚的石墨烯层。除了电磁行为外，还强调了由石墨烯覆盖的天线引起的热效应。石墨烯的电导率高度依赖于其化学势和弛豫时间，因此进行了参数研究以确定石墨烯涂层天线优于典型无石墨烯天线的公差范围。发现值的范围是 0 <μC< 0.5 eV 和τ< 0.4 ps，分别为化学势和弛豫时间。防止后向加热问题，确保消融区域围绕天线尖端呈球形。考察了石墨烯层对组织散热的影响、坏死组织比例（电磁能对癌组织的损伤）以及同轴双缝隙天线的治疗时间。结果表明，散热集中在槽（癌组织区域）周围，石墨烯覆盖的双槽天线可以在更短的时间内实现更高的坏死组织比率。