The characteristics of the polymer modulator are determined by many interrelated physical phenomena. The key issue of this paper is to find out the optimum device parameters and corresponding conditions by taking into account all the related factors. The optical field in ridge waveguides is calculated using the FEM software with MATLAB and then fit to a Gauss function. The parameters such as half-wave voltage, bandwidth are calculated using the FEM software with FORTRAN language. In the calculating results, the comprehensive characterization of the polymer modulator with 1.21v half-wave voltage, 91GHz bandwidth is presented, electro-optic interaction length is 20mm, electro-optic coefficient is 55pm/V, and wavelength is 1.319μm. These results fit the 0.8v half-wave voltage, electro-optic interaction length is 30mm reported on Science perfectly. More important, five structures of polymer modulators are presented all together and are compared of the merits and shortcomings. One of them is a combination of CPW and microstrip lines. The characterization of this structure is like that of the microstrip lines with single arm electrode on one arm of the waveguide, but it solves the problem of microstrip-coaxial transition and corona polarization.