Mode-coupling analysis of multipole symmetric resonant add/drop filters

Time-dependent mode-coupling theory is used to analyze a type of resonant a dd/drop filter based on the excitation of degenerate symmetric and antisymm etric modes. Flat-top transfer functions are achieved with higher order fil ters that utilize multiple resonator pairs, designed to satisfy the degener acy conditions. The resulting analytic expressions lead to an equivalent ci rcuit and the transfer characteristics of the filter are related to standar d L-C circuit designs.