A method for the design of dielectric multilayer bandpass filters

A design method of a dielectric multilayer bandpass filter for optical‐communication is proposed, and its feasibility is demonstrated for an example of the design. The design procedure is to replace each resonator in a specified LC bandpass filter by a corresponding dielectric multilayer resonator. This LC bandpass filter is obtained from an LC lowpass prototype through a frequency transformation. New structures of a dielectric multilayer resonator are proposed, and the equations necessary for the design are derived. A method to correct a design error due to excess phase also is discussed. With the present design method, an arbitrary polynomial characteristic (Butterworth, Chebyshev, and Bessel, etc.) can be realized as a dielectric multilayer bandpass filter. A good agreement is found between the designed and actual performance for a narrowband bandpass filter.