Modelling and analysis of coplanar waveguide for LiNbO3 optical modulators

Hybrid-mode analysis is carried out for coplanar waveguide applicable to Z-cut Ti:LiNbO₃ optical modulators. The analysis is based on the integral equations. Generalized trial quantities are introduced as virtual adjustable sources in the equivalent network representation of the structure. The microwave effective index and the characteristic impedance as a function of the operating frequency of the coplanar are computed. The effect of the buffer layer thickness on both the microwave effective index and the characteristic impedance is studied. The effect of the structure dimensions on both the microwave effective index and the characteristic impedance is also discussed. Finally, the obtained results are compared and the data furnished by the literature. A good accuracy is obtained