Theoretical Study of Phase and Amplitude Characteristics of Microwave Coplanar Delay Line Containing Thin Ferroelectric Layer
We theoretically studied the microwave coplanar line of different geometry based on MgO substrate with a thin (30 nm) ferroelectric layer under the external electric field using the environment of 3D modeling in COMSOL Multiphysics®, RF Module, Frequency Domain. Frequency dependence of delay line coefficient S21 was obtained. Sizes of the microstrip and the gap between the strip and the ground below which the influence of turns undercuts geometry of microstrip upon the coefficient S21 becomes significant were found. Calculation of influence of an external electric field on the line delay time were accomplished. The results of the calculations show that the time delay under an external field change significantly. It provides to create the delay line controlled by voltage.