FINITE-ELEMENT ANALYSIS OF PROPAGATING, EVANESCENT, AND COMPLEX-MODESIN FINLINES

The finite element method is employed to analyse the characteristics o f propagating, evanescent, and complex modes in finlines. The recently developed mixed-interpolation-type triangular elements are used, wher e no spurious solutions appear and consistency with the published resu lts is obtained. The existence of the complex mode for both the even m ode and the odd mode in finlines is found for particular structural pa rameters and at a certain frequency range. In addition, a new formulat ion is made for the determination of the characteristic impedance by t he finite element method. The possible electric field distributions of the dominant and higher order modes including the evanescent and comp lex modes are also presented.