In low earth orbiting satellite communication systems, antennas are key elements for radio frequency transmitters and receivers. There are different types of antennas used on satellite communication systems. One of them is the antenna used in payload data transfer communication subsystem. Payload data transmitters for space segment should utilize the radio frequency power efficiently due to the limited power budget of the spacecraft. For low elevation angles of a low earth orbiting satellite, the free space loss increases as expected and it should be compensated. One way of this compensation is to employ an antenna having isoflux pattern. Therefore, in this paper, a circularly polarized X‐Band choked ring horn antenna is designed, optimized and manufactured due to its isoflux radiation characteristic and medium power handling capability. Initially, an analytical approach from the literature is explained and then the physical dimensions of the proposed antenna are optimized, iteratively, employing a commercially available electromagnetic solver. Next, a prototype has been manufactured to verify the radiation, return loss and port isolation characteristics and they are presented in the related section. Moreover, the results of the presented antenna have been compared to the ones available in the literature. These comparisons show that gain of the designed antenna at ±64° elevation angle has higher gain with respect to the compared ones. In addition, its axial ratio value is smaller than 6.5 dB for different azimuth angles between 8025 and 8400 MHz. Unlike the other studies given in the literature that have gain higher than 2 dB at ±64° elevation angle, in this study all design parameters have been presented to utilize through the operating bandwidth.

中文翻译：

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卫星有效载荷数据发射机的扼流圈喇叭天线设计

在低地球轨道卫星通信系统中，天线是射频发射器和接收器的关键元件。卫星通信系统上使用不同类型的天线。其中之一是有效载荷数据传输通信子系统中使用的天线。由于航天器的功率预算有限，用于空间段的有效载荷数据发射器应有效利用射频功率。对于低地球轨道卫星的低仰角，自由空间损耗按预期增加，应予以补偿。这种补偿的一种方式是采用具有等通量方向图的天线。因此，本文基于等通辐射特性和中等功率处理能力，设计，优化和制造了圆极化X波段扼流圈式喇叭天线。原来，解释了文献中的一种分析方法，然后使用市售电磁求解器迭代地优化了所建议天线的物理尺寸。接下来，制造了一个原型以验证辐射，回波损耗和端口隔离特性，并在相关章节中进行介绍。此外，已经将所提出的天线的结果与文献中的结果进行了比较。这些比较表明，相对于所比较的天线，设计天线在±64°仰角处的增益具有更高的增益。此外，对于8025和8400 MHz之间的不同方位角，其轴向比率值小于6.5 dB。与文献中给出的其他研究不同，在仰角±64°时增益高于2 dB，