Cross- Coupling Substrate Integrated Waveguide Filter for 5G FR2 Band

Substrate integrated waveguide (SIW) bandpass filter structures based on six-degree cross-coupled folded configuration are considered. Various magnetic and electric cross-couplings configurations can improve filter stopband performance or decrease in-band group delay ripple or both properties simultaneously, compared to conventional Chebyshev prototype. For these purposes a novel implementation of negative cross-coupling scheme consisting of so-called “double-sided short-circuited coplanar waveguide (CPW) line” is proposed. The four SIW bandpass filters with the same center frequency of 28 GHz and bandwidth of 1.2 GHz for implementation on a single-layer Rogers RT/Duroid 5880 substrate with thickness of 0.254 mm are synthesized. Obtained quasi-elliptic cross-coupled filters are compact and attractive for 5G FR2 applications.