为了提高通信系统的通信容量，设计了一种基片集成波导(SIW)双圆极化贴片天线。该天线由耦合器、贴片天线构成。基于空腔模型研究，耦合器采用SIW 结构，其输出端信号在较宽的带宽内具有良好的稳定性；在分析微带天线理论基础上，引入贴片天线作为辐射单元，结构简单，易于实现；在传输线模型理论中，天线输入端口采用共面波导(CPW)的转换结构是必不可少的，可以直接与SMA 转接头相连，方便测试。该天线可以根据其应用需求调整工作极化方式，可以实现左旋圆极化(LHCP)和右旋圆极化(RHCP)。通过测试加工后的天线验证了仿真数据。结果表明,该天线相对带宽超过18%(19.5 GHz~23.5 GHz)，在工作频率范围内，轴比参数小于2，可实现增益7.4 dB。

A kind of dual-circular polarization patch antenna investigated and synthesized in the Substrate Integrated Waveguide(SIW) technology is designed in order to improve the communication capacity of communication systems. This antenna consists of a coupler and a patch antenna. The coupler adopts SIW structure based on the cavity model research, whose output signals are stable in wide bandwidth. Based upon analysis of micro-strip antenna theory, patch antenna is easy to be implemented due to its simple structure. In the transmission line model theory, the antenna input ports with the transformation structure of Coplanar Waveguide(CPW) is indispensable in order to enable the direct connect with the SMA connector. Depending on the requirements of its specific application, the antenna can operate in either Left-Hand Circular Polarization(LHCP) or Right-Hand Circular Polarization(RHCP). The testing results of the antenna validate the simulation data, and show that the antenna has a relative bandwidth above 18%(19.5 GHz-23.5 GHz) and the axial ratios are below 2 within the whole frequency band; and the realizable gain of the antenna is 7.4 dB.