Design procedure for ferrite microstrip DC blocks

We have investigated the theoretical behavior of the microstrip dc blocks on magnetized ferrite substrates. A full-wave analysis is applied to determine the effective dielectric constants and the characteristic impedances of the fundamental eigenmodes associated with the coupled lines and their frequency dependence. Numerical results are presented for the input standing wave ratio, input reflection coefficient, and transmission loss. The influence of the applied dc magnetic bias field on the transmission characteristics of these structures is also examined. A good agreement was observed for the particular cases available in the literature.