Design of wideband bandpass filters using Si-BCB technology for millimeter-wave applications

This paper presents the design of two types of wideband bandpass filters with different bandwidths for millimeter-wave D-band applications. The proposed filters are implemented on a three-layer structure deposited on a 400-µm silicon (Si) bulk with benzocyclobutene (BCB) as the substrate. The characteristics of the basic structures for these two types of bandpass filters, a square ring resonator and a stub-loaded multiple-mode resonator (MMR), are studied. The bandpass filters are implemented and measured, and the measurement results agree with the simulations well and exhibit bandpass filtering responses at 134.3 GHz and 132.8 GHz, with fractional bandwidths of 25.7% and 34.3%, respectively.