THEORETICAL STUDIES OF REFLECTION AND DIFFRACTION OF EM WAVE BY GRATING
电磁波在光栅表面上反射和衍射的理论研究

The electromagnetic field problem of a rectangular grating illuminated with TM wave is studied theoretically by means of rigorous field-matching and moment method. The numerical calculations show that the grating, as a frequency scan antenna, can produce perfect blazing in a wide range of incident angle only through adjusting the size of width and depth of the groove no matter Bragg condition is satisfied or not. Higher efficiency and broader frequency band of - 1 order diffraction wave can be achieved only at the larger reciprocal incident angle. And very broad frequcncy band can be expected when the grating is employed as a reflecting mirror in an orotron. The effective grating position and phase change of reflection wave by grating are also numerically presented.