交叉耦合微波滤波器可利用输入/输出耦合(即源与负载的耦合)构成交叉耦合以达到优化结构和减小体积的目的。首先基于波导缝隙耦合等效电路模型得到了S参数描述的输入/输出耦合系数;其次以X波段滤波器为例,使用HFSS软件抽取了输入/输出耦合结构的耦合系数,并根据目标耦合系数确定了其输入/输出波导耦合结构参数,从而将抽象的耦合矩阵转化成实际滤波器的结构尺寸;最后对比仿真结果与计算曲线验证了所提出方法的可行性。
The cross - coupled microwave filter can be designed with input - output coupling(source- load coupling), to optimize the structure and minimize the volume. In this paper, the relationship between S parameters and input- output coupling coefficient is derived from the equivalent circuit model of the waveguide aperture coupling structure. The input - output coupling coefficient of X- band filter is extracted by the HFSS software, and the input- output coupling structure parameters are determined according to the target coupling coefficient. Therefore the theoretical coupling matrix can be translated into the real filter's structure dimensions. The comparison between simulation and computation verifies the feasibility of the proposed method.