A study on the feeding system for the tapered-slot-antenna having ultra broadband characteristics and its array

锥形缝隙天线(TSA)具有增益高、带宽宽、结构简单等优点，因此受到了众多研究者的关注。最近，采用正交馈电技术的时分天线(O-TSA)被提出作为一种有用的时分天线阵列的单元天线。这种类型的天线以这样的方式构造，即TSA元件设置成垂直于馈电网络的衬底。由这些新设计的O-TSA单元组成的阵列天线可以实现大规模TSA阵列的简单馈电系统。然而，通常的O-TSA元件由微带线馈电。人们认为，由微带线馈电的O-TSA元件由于其馈电系统不需要的辐射，将显示出高的交叉极化特性。因此，本研究提出了一种新型的由共面波导构成馈电系统的O-TSA元件。为了验证这些天线的性能，S…构建了更多的O-TSA样品，并在SHF波段进行了测试。实验结果表明，测试天线在辐射方向图和回波损耗特性方面都有较好的表现。其次，本研究提出了一种新型的采用双馈技术的O-TSA元件。该双馈电系统中的两个O-TSA元件通过一个耦合槽与馈线电磁耦合。这种新设计的O-TSA元件的馈电系统是利用微带线构建的。通过控制过渡段开路段的长度，实现了双TSA元件与馈电系统之间的阻抗匹配。使用这些双O-TSA单元的阵列天线可以实现大规模TSA阵列的简单馈电系统。通过实验确定了天线的最佳几何参数，天线由普通聚四氟乙烯玻璃纤维基板制成。采用双馈技术实现了测试天线的宽带回波损耗。测试天线的辐射方向图也是对称的。天线的交叉极化电平在视轴方向上被抑制到-25分贝以下。该测试天线的峰值增益约为10dBI。实验结果证实，所提出的O-TSA元件在辐射模式和回波损耗特性方面都表现良好。因此，这些O-TSA单元被认为是用于大规模TSA阵列的有用天线。较少

A tapered slot antenna (TSA) has been investigated by many researchers, because a TSA has several advantages such as high gain, wide bandwidth and simple configuration. Recently, a TSA using an orthogonal feeding technique (O-TSA) has been proposed as a useful element antenna for a TSA array. This type of antenna is constructed in such a way that the TSA element is set perpendicular to the substrate for a feeding network. An array antenna composed of these newly designed O-TSA elements enables the realization of a simple feeding system for a large-scale TSA array. The usual O-TSA element is, however, fed by a microstrip line. It is thought that an O-TSA element fed by a microstrip line will show high cross-polarization characteristics because of unwanted radiation from its feeding system. Therefore, new types of O-TSA elements, in which the feeding systems are constructed by a coplanar waveguide (CPW), are proposed in this study. In order to verify the performances of these antennas, s … More ome O-TSA samples were constructed and tested at the SHF-band. The experimental results showed that the test antennas performed well in terms of both radiation pattern and return-loss characteristics. Next, the new type of O-TSA element using a dual feeding technique was proposed in this study. The two O-TSA elements in this dual feeding system are coupled electromagnetically via one coupling slot to the feeding line. The feeding system of this newly designed O-TSA element was constructed by using a micostrip line. Impedance matching between the dual TSA element and the feeding system was achieved by controlling the length of open stub in the transition. The array antenna using these dual O-TSA elements enables the realization of a simple feeding system for a large-scale TSA array. The optimum geometrical parameters were determined experimentally, and the antennas were made of a usual Teflon fiberglass substrate. The broadband returnloss was achieved in the test antenna using a dual feeding technique. Symmetrical radiation patterns were also obtained for the test antenna. The cross-polarization levels of the antenna were suppressed to below-25 dB in the boresight direction. The peak gain was about 10 dBi in this test antenna. The experimental results confirmed that the proposed O-TSA elements performed well in terms of both radiation patern and returnloss characteristics. Therefore, these O-TSA elements are considered to be useful antenna for a large-scale TSA array. Less