Developmental Study of Cavity-Backed Slot Antennas Consisting of Two Conductive Plates Separated by Wires

背腔式缝隙天线被用作太阳能卫星的微波能量发射天线单元。与其他类型的天线相比，该天线元件在机械强度、散热和低轮廓结构方面具有优势。提出了一种新型的背腔缝隙天线，该天线由细导线或厚柱子隔开的两个导电板组成，首先给出了短端探头激励的高度为3 mm的天线单元的有效设计方法，并分别推导了有限导电板单元和无限导电板单元的天线参数。在2.45 GHz频率下，两者都实现了良好的阻抗匹配。计算表明，天线参数对阵列天线的设计是有效的，激励单元与相邻单元在H面方向上的互耦相当大。对九单元和二十五单元阵列天线的附加计算表明，对于这两种阵列几何形状，回波损耗和互耦的量几乎相同。因此，对九元阵列天线的互耦分析为我们提供了在大规模阵列天线中互耦的良好前景。其次，我们讨论了另一种由倒F元激励的天线单元。这些元件由两个导电板组成，由八根12毫米高的正方形柱子隔开。如果使用金属管作为支柱，可以实现一种简单的方法来配置元件，因为两个导电板是用螺丝固定的。此外，该天线配置具有这样的优点，即馈线设置在底部导电板上，而不与上板连接。这种类型的元素配置的帖子比前一个要少。

The cavity-backed slot antenna is used as a microwave energy transmission antenna element for solar power satellites. The antenna element has advantags over other types of antenna in mechanical strength, heat dissipation and a low profile structure. We propose new types of cavity-backed slot antenna consisting of two conductive plates separated by thin wires or thick pillars.First we show an effective design method of an antenna element with the height of 3 mm excited by the short-ended probe and derived two kinds of antenna parameter for the element with finite and infinite conductive plates, respectively. Both realize a good impedance matching at the frequency of 2.45 GHz. It is clarified from calculations that the antenna parameters are effective for the array antenna design and that the mutual coupling between the excited element and its adjacent ones in the direction of H-plane is considerably large. Additional calculations for the nine-element and the twenty-five-element array antennas show that quantities of return loss and mutual couplings are almost the same for both array geometries. So the evaluation of mutual coupling for the nine-element array antenna gives us good perspectives of that in the large-scale array antenna.Second, we discussed another type of antenna element excited by an inverted-F element. The elements are composed of the two conductive plates separated by the eight square pillars of 12 mm high. If we use metal pipes as the pillars, we can realize an easy method to configure the element as the two conductive plates are fixed with screws. Furthermore, the antenna configuration has advantages such that the feeder is set on the bottom conductive plate and is not connected with the upper plate. This type of element is configured with fewer posts than the previous one.