EM based design of square-ring vialess bandpass filters

A simple technique for the design of new, vialess square-ring bandpass filters is presented. The proposed technique is based on the full-wave electromagnetic simulation of a single filter section with variable offset distance to realize a wide range of bandpass filters with flexible specifications at any given center frequency. The new, multilayered filter configurations are vialess in nature, taking advantage of the broadside coupling between different layers for simple fabrication. Two- and three-resonator Chebyshev bandpass filters with 20% and 10% bandwidth are designed at a center frequency of 2 GHz and the theoretical response is validated by measurement. Due to the EM based design approach, the proposed technique offers a high degree of accuracy. These new configurations are suitable for a variety of multilayered fabricational technologies.