抛物线的焦点

Feed positioning in the way that its phase center exactly coincides with the focus of the offset parabola and its direction so that the radiation maximum falls in the geometric center of the elliptic reflector surface are not intuitive at all, as in classic parabolic antennas.

馈源用这样的方式定位——其相位中心准确位于偏馈抛物线反射器的焦点，方向也要准确，这样辐射最大值才能落在椭圆形反射面的几何中心，这样一点也不直观，正如标准的抛物面天线。

The reason for this is that ratio F/D determines the angle the edges of the parabola are seen from the focus.

原因就是F/D的比率限定了抛物线焦点到边缘的角度。

Focus of the parabola, practically, is in the entrance in the waveguide of the converter.

抛物线的焦点实际上是在变频器波导入口处。

A calculation method and calculation results that show that a new kind of shaped paraboloid antennas can produce a ringy radiation pattern is presented.

通过数值计算发现将抛物线绕通过焦点的非抛物线对称轴旋转而形成的赋形抛物面天线可产生环状的方向图主瓣(此主瓣指的是主瓣最大值处)。

The specificity of the surface gained in this way is that when the beam of rays parallel to its axis of rotation falls on it, the beam is reflected so that all the rays meet in one point, known as the focus, in the same way that optical lenses focus light rays in their focus.

抛物线的表面或曰抛物面，是由抛物线围绕其对称轴旋转而成，其特点是，和抛物线对称轴平行的射线波束被抛物面所反射，所有的电波都在同一点汇聚， 1 September，2009 3D 角反射天线作馈源的 5.8GHz 偏馈抛物面天线我们把这点叫做焦点。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。