在现代无线电通讯等应用中，为了增强接收信号，人们将接收天线制成旋转抛物面，这是利用了抛物线的光学性质，图１即抛物线焦点处的点光源射到抛物线的凹反射镜上，反射后与其对称轴平行（如图１），或者说平行于抛物线对称轴的光射到抛物线的凹反射镜上，反射后会聚在其... In modern radio communications and other applications, in order to enhance the received signal, people make the receiving antenna into a paraboloid of revolution, which uses the optical properties of the parabola. Figure 1 is the point light source at the focus of the parabola and the concave reflector on the parabola. After its axis of symmetry (Figure 1), or parallel to the axis of symmetry of the parabolic light on the parabolic concave mirror, after reflection will converge on it ...