Permittivity determination in the T-junction with multimode resonator

A physical model of microwave measuring of the permittivity on the basis of the waveguide T-junction with the multimode resonator is considered. The rigorous solution of the diffraction problem is obtained in the form of the linear algebraic equations system. Amplitude-frequency characteristics for various relations between wavelengths, geometrical sizes of structure and the material parameters of media are calculated. The practical application of the considered model — the trapped modes regime in the multimode resonator and resonant wave propagation in the medium are selected.