A Design of Flattop-beam Shaper at Millimeter Wavelengths

Beam shaping technique for generating flattop beam has long been used in optics, and there are many methods to design flattop-beam shapers in optics. Flattop beam is also important in some applications at millimeter wavelengths such as in the quasi-optical power divider, however, there are few design method for the flattop-beam shaper used at millimeter wave frequencies and the design method of optics are not suitable to the beam shaper at millimeter wave frequencies, so a design method for the flattop-beam shaper at millimeter wave frequencies is presented in this paper. Several flattop-beam shapers in the form of diffractive element have been designed and simulation results are presented.