A signal interleaver/ deinterleaver based on ring resonators is proposed and analyzed with the transfer matrix and the Z-transform techniques. The proposed structure is composed of rings connected in a closed loop and is termed a “compound ring resonator circuit.” The interleaver/deinterleaver circuit is designed to meet wavelength division multiplexing (WDM) specifications for two channels of spacing of $50\mathrm{GHz}$ , a channel free spectral range of $100\mathrm{GHz}$ , a crosstalk of $-24\mathrm{dB}$ , and a maximum dispersion of $\pm 22\mathrm{ps}∕\mathrm{nm}$ over a $\pm 10\mathrm{GHz}$ bandwidth at a wavelength of $1.55\mu \mathrm{m}$ . Compared with previous circuits of this nature, this circuit possesses a smaller number of rings, a simpler design, does not require apodization, exhibits less dispersion, and offers a higher fabrication tolerance and density.