Research work of reconfigurable millimeter wave antenna

在这项研究工作中，我们试图实现一种可重构的毫米波天线。为了实现可重构天线，作为第一步，我们开发了两种天线机构。一种是一种微带线天线，其电流被控制为延缓大线或相邻线的电流。另一种是通过激励导体元件，以矩阵的方式排列在由介质材料隔开的两层中。为了设计天线，我们通过FDTD仿真和有限元仿真计算了天线在空气中的波轨迹。利用硅衬底和金属薄膜的体微机械加工技术和PDMS和SU8的软微机械加工技术制作了天线，测量了天线在50 GHz频段的传播特性，与计算结果吻合较好。为了简化毫米波领域的可重构天线，重点研究了压电材料的磁导率对天线性能的影响，采用CIP计算和FDTD计算相结合的方法设计了新型加热器驱动天线。所设计的天线采用MEMS工艺制造。对制作的天线进行了测试，但由于构图精度和隔热结构的原因，天线的发射性能并不理想。为了驱动天线，我们设计并制作了两种类型的RF-MEMS开关。一种是悬臂式，另一种是X-Bar式。这两种类型的开关都是由沉积在硅衬底上的PZT薄膜驱动的，本文的研究工作证明了所设计的天线机构和结构对于可重构微天线是可行的，可以得出结论，我们的研究工作对于实现毫米波或更高频段领域的新型天线和开关具有参考价值。

In this research work, we have tried to realize a reconfigurable millimeter wave antenna. To realize the reconfigurable antenna, as a first step, we developed two types antenna mechanism. One is a kind of micro-strip line antenna in which the electric current is controlled to be delay for the grand line or neighboring lines.Another type is a novel mechanism by actuating conductor elements which is arranged in matrix manner in two layers that is separated by dielectric material.To design the antennas, we calculated the characteristics of wave trajectory in the air from the antenna by FDTD simulation and finite element simulation. The optimization technique was also used to define their optimum shape.The designed antenna was fabricated by use of the bulk micromachining with silicon substrate and thin metal film and by use of soft micromachining with PDMS and SU8.We measured the wave propagation from the fabricated antenna in 50GHz range, the characteristic of the antenna agreed well with the calculated results.To simplify the reconfigurable anntena in the field of millimeter wave, we focused on the dependency of the permeability of piezoelectric material, we designed new heater driven antenna using both CIP calculation and FDTD calculation. The designed antennas were fabricated using MEMS process. The fabricated antennas were tested but the emition properties were not efficiency because of the patterning accuracy and heat-insulated structure.To drive the antenna we designed and fabricated two types RF-MEMS switch. One is a cantilever type, and another type is a X-Bar type. Both type switches are driven by the PZT thin film deposited on Si substrate.In this research work, we prove that the designed mechanism and structure for the antenna is feasible for reconfigurable micro antenna.We can conclude that our research work is worth for realize new antenna and switch in the field of millimeter wave or more high frequency field.