Application of the extinction theorem to some antenna problems

The Ewald-Oseen (1915, 1916) extinction theorem is applied to some antenna problems. In particular, the theorem is extended to the concept of surface impedance and this form is developed into a method for analysing the performance of an antenna in the presence of a finite ground screen. The approach first simulates the antenna over an infinite perfectly conducting plane and then further processes the resulting antenna currents to yield the gain pattern over a finite screen.