Analysis of slot lines on ferrite substrate by the integral kernel expansion method

A slot line on a normally magnetized ferrite substrate has been analyzed, since this structure is expected to provide potential applications for nonreciprocal devices. Firstly, a dual integral equation for two tangential components of electric fields in the slot is derived and then the kernel expansion technique is applied to solve the equation. The dispersion relation obtained shows discontinuous behaviors at two marginal frequencies which give the frequency range to permit magnetostatic forward volume wave propagation between them. The authors emphasize here that a nonreciprocal property will become more conspicuous at frequencies closer to the marginal frequencies