Research of the active antenna fed by coplanar waveguide for satellite communication

近年来，共面波导（CPW）的普及率显著增加。共面波导的优点是带宽更宽，相邻两条线之间的互耦更小，更容易与固态有源器件集成。在过去的几年里，对共面波导馈电的线极化天线进行了大量的研究，如贴片天线、环形天线和缝隙天线，但迄今为止只有少数尝试实现了共面波导馈电的圆极化天线。提出了一种新的共面波导馈电的圆极化印刷天线结构，并对该天线进行了数值模拟和测量分析，近来已经研究了用于移动的卫星通信的具有电自动跟踪机构的各种类型的车辆天线。这样的天线需要移相器或开关来形成期望的波束。在这项研究中，我们还提出了一个中等增益波束切换天线阵列通过修改圆极化天线馈电的共面波导。作为一个例子，由四个元素组成的阵列进行了演示，在12 GHz频段的一些模拟结果。该阵列应该有四个1位（180度）移相器或开关来跟踪卫星。最后，对集成微波开关电路的天线进行了研究。

The popularity of coplanar waveguide, (CPW) has increased significantly in recent years. The advantages of CPW are wider bandwidth, smaller mutual coupling between two adjacent lines and easier integration with solid active devices. Over the past few years a considerable number of studies have been carried out on the linearly polarized antenna fed by CPW such as patch antennas, loop antennas and slot antennas, but only a few attempts have so far been made at realizing a circularly polarized antenna fed by CPW.In this study, we proposed a new structure of the circularly polarized printed antenna fed by CPW and analyze this antenna fed by using both a numerical simulation and measurement.Moreover, various types of vehicle antennas with, an electrically auto-tracking mechanism have been studied for mobile satellite communications recently. Such antennas require phase shifters or switches to form a desired beam. In this study, we also proposed a medium-gain beam-switching antenna array by modifying the circularly polarized antenna fed by.CPW.As an example, an array composed of four elements is demonstrated with some simulated results at 12 GHz band. The array is supposed to have four 1-bit (180-degree) phase-shifter or switches to track the satellite. The results show the possibility of a low-cost and small-size beam-switching array.Finally, the antenna integrated with the microwave switching circuits was also investigated.