Determination of Guided Wavelength in Multi-layer Microstrip Structures via Open Circuit T-resonator

In this work, an open circuit T-resonator is used to determine the guided wavelength of a dielectric structure with multiple layers having different relative permittivity values. The multi-layer substrate consists of two single-sided copper clad FR4 laminates and a layer of PETG material between these laminates to form a sandwich structure. In a T-resonator model, standing waves impacts the insertion loss of the transmission line based on the electrical length of the stub resonator that is linked to this microstrip line. By taking advantage of this property, the wavelength determination is achieved with the help of the results obtained by the Comsol software simulations. Additionally, to illustrate the feasibility of the method, we have simulated a classical microstrip antenna designed by considering the results of the T-resonator simulations. The overall results indicates that the suggested method is useful to determine the guided wavelength of multi-layered structure with different dielectric constants.