Microwave ablation(MWA) is a cancer treatment method. The tumor tissue absorbs electromagnetic energy, which heats and kills it. A microwave ablation antenna plays a critical role in this process. Its radiation field ...Microwave ablation(MWA) is a cancer treatment method. The tumor tissue absorbs electromagnetic energy, which heats and kills it. A microwave ablation antenna plays a critical role in this process. Its radiation field must completely cover the tumor but not the healthy tissue. At present, the radiation pattern of most invasive ablation antennas is spherical.However, in the clinic, the shape of some tumors may be asymmetrical or the antenna cannot be inserted into the center of the tumor for some other reason. In order to solve these problems, a directional heating antenna for microwave ablation is proposed in this paper. The proposed antenna, operating at 2.45 GHz, consists of a monopole and a reflector. The feed is given by a substrate integrated coaxial line(SICL) and coplanar waveguide(CPW). The omnidirectional radiation field of the monopole is reflected by a reflector that is extended from the outer conductors of the SICL to form a directional radiation field. The impedance matching network is designed on SICL to match the antenna to 50 Ω. The antenna is fabricated using a mature printed circuit board(PCB). The reflection coefficient of the antenna in porcine liver tissue measured by a vector network analyzer shows good agreement with the simulations. Then, an ablation experiment in porcine liver is conducted with power of 10 W for 10 min, and the experimental results confirm the validity of the design.展开更多
未来通信系统将工作于更高频率,并提供更高传输速率。频率提升将导致难以提供区域宽波束覆盖,因此灵活捷变的波束跟踪将成为技术发展的必然趋势。本文报道的太赫兹波束回溯天线阵列可为灵活捷变的波束跟踪提供良好解决方案。该天线阵列...未来通信系统将工作于更高频率,并提供更高传输速率。频率提升将导致难以提供区域宽波束覆盖,因此灵活捷变的波束跟踪将成为技术发展的必然趋势。本文报道的太赫兹波束回溯天线阵列可为灵活捷变的波束跟踪提供良好解决方案。该天线阵列接收40GHz的导频信号,回溯波束传输的信号是120GHz。仿真结果表明文中所述具有三明治堆叠结构的天线阵列可成功实现入射波的回溯功能。天线辐射方向图显示该天线阵列在20°入射波条件下,其回溯波束在19.9°位置处,增益为23.87 d B,回溯方向相对误差仅为0.5%。这意味着在5 km传输距离下,水平误差仅为8.7m。展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. U1966201)the Fundamental Research Funds for the Central Universities, China (Grant No. A03019023801224)。
文摘Microwave ablation(MWA) is a cancer treatment method. The tumor tissue absorbs electromagnetic energy, which heats and kills it. A microwave ablation antenna plays a critical role in this process. Its radiation field must completely cover the tumor but not the healthy tissue. At present, the radiation pattern of most invasive ablation antennas is spherical.However, in the clinic, the shape of some tumors may be asymmetrical or the antenna cannot be inserted into the center of the tumor for some other reason. In order to solve these problems, a directional heating antenna for microwave ablation is proposed in this paper. The proposed antenna, operating at 2.45 GHz, consists of a monopole and a reflector. The feed is given by a substrate integrated coaxial line(SICL) and coplanar waveguide(CPW). The omnidirectional radiation field of the monopole is reflected by a reflector that is extended from the outer conductors of the SICL to form a directional radiation field. The impedance matching network is designed on SICL to match the antenna to 50 Ω. The antenna is fabricated using a mature printed circuit board(PCB). The reflection coefficient of the antenna in porcine liver tissue measured by a vector network analyzer shows good agreement with the simulations. Then, an ablation experiment in porcine liver is conducted with power of 10 W for 10 min, and the experimental results confirm the validity of the design.
基金Project supported by the National Key R&D Program of China(No.2018YFB1801505)the National Natural Science Foundation of China(Nos.61527805 and 61731001).
文摘未来通信系统将工作于更高频率,并提供更高传输速率。频率提升将导致难以提供区域宽波束覆盖,因此灵活捷变的波束跟踪将成为技术发展的必然趋势。本文报道的太赫兹波束回溯天线阵列可为灵活捷变的波束跟踪提供良好解决方案。该天线阵列接收40GHz的导频信号,回溯波束传输的信号是120GHz。仿真结果表明文中所述具有三明治堆叠结构的天线阵列可成功实现入射波的回溯功能。天线辐射方向图显示该天线阵列在20°入射波条件下,其回溯波束在19.9°位置处,增益为23.87 d B,回溯方向相对误差仅为0.5%。这意味着在5 km传输距离下,水平误差仅为8.7m。
