Influence of the fabrication errors on IC multilayer filter circuits

New data are presented on the millimeter-wave effects of fabrication errors in multilayer passive components. This has particular significance for modern hybrid integrated circuits, where developments in materials technology allow the designer to simultaneously improve both electrical performance and circuit packing density through the use of multilayer structures. Studies have been conducted on edge-coupled band-pass filters as the component used to assess the performance of the multilayer circuits and fabrication error at 35GHz. The outcomes of the work showed the performance benefits that accrue from the use of multilayer circuits, in terms of a significant improvement in bandwidth while maintaining the quality of the filter roll-off. A particularly significant error that was quantified was that of skew between conductors on different layers, where it was found that a skew angle of only 0.1° resulted in very significant changes in bandwidth and insertion loss.