Method of induced magnetomotive forces in comparison with FDTD simulation in problems of waveguide coupling by a narrow slot

The problem of waveguide coupling by a narrow slot is solved by the method of induced magnetomotive forces. Using an approximate analytical solution of integral differential equations on the magnetic current, the current distribution on a slot can be found. The results of calculation of transmission power of different types of slot are compared with the same ones obtained by the FDTD method.