The electrode structure analyses of CPW on LiTaO3 electro-optical modulator

The main purpose of this paper is to study the relationship of CPW´s structural parameters while the benchmark impedance is 50 Ω, and the CPW of LiTaO₃ electro-optical modulator is taken as an example. Conformal mapping theory is used to obtain the numerical relationship of electrode structure, thickness of the substrate and properties parameters, the results show that the little change of electrode width would affect the CPW remarkably, 1 μm shift of the center conductor width will induce the change in the benchmark impedance ranging from 5.35% to 5.78%. The formulas and analyses are useful in the design of CPW.