仿真咨询

我建好对称阵子列天线的模型，仿真也通过了，想看远场区的方向图，可是在执行以下步骤时：results--creat report--far fields--3d polar plot，出现了一下的错误：
duichenzhengzilie (E:/ansoft/)
HFSSDesign1
[error] Field, Near Field, and Far Field reports cannot be created without specifying an appropriate setup geometry - polyline, sphere, or infinite sphere respectively. Please create one before creating a report. (4:35 下午 三月 19, 2010)
[error] Field, Near Field, and Far Field reports cannot be created without specifying an appropriate setup geometry - polyline, sphere, or infinite sphere respectively. Please create one before creating a report. (4:43 下午 三月 19, 2010)
麻烦各位大侠看看该怎么修改。

这句话好像是说：没有指定合适的几何体