The effect of discrete scatterers on a low sidelobe antenna

The effect of randomly distributed scatterers placed in the far field of an antenna is explored. A technique for predicting the effects of specular scatterers on antenna performance has been developed. Laboratory testing of a low sidelobe antenna indicated an acceptable low sidelobe level. However, when the antenna was field tested, it exhibited average radiated power levels off the main beam that were significantly greater than those anticipated. In an effort to determine the cause of this increase, a computer model of an antenna in a field site has been developed, which includes the calculation of the total scattered power of the antenna main beam and sidelobes from specular reflectors distributed over the far field of the antenna.