Large depth of field and uniform axial intensity distributions are important in many practical applications. Lots of optical elements have been proposed for this end, such as full-aperture logarithmic axicons (LAs), annular-aperture LAs and apodized annular-aperture LAs. In millimeter/submillimeter (mm/submm) range, the refractive-diffractive behaviors (including transverse and longitudinal intensity distributions) behind these axicons illuminated by a plane wave are calculated by rigorous electromagnetic analysis method in our paper. Many important features of these axicons are concluded by comparing their refractive-diffractive field distributions