The structure and performance parameters of coplanar waveguide electro-optic modulator with thicker electrodes and buffer layer are analyzed using the extended point-matching method.The relationship between the parameters and the modulation characteristics is obtained from selecting by simulation the proper thickness of the electrodes and buffer layer

optimizing the modulator performance and realizing broadband modulation.The results agree well with those obtained by using the conformal mapping method.This method provides a simple and fast approach to the analysis of the multi-layered structures with finite electrode thickness.