An Enhanced Design Flow for Cavity Combline Filters

Cavity combline filters and multiplexers are widely used in commercial and military systems. Many of these filters use finite transmission zeros to increase selectivity in the stopbands, which are realized by introducing cross couplings into the combline filter topology. The design process may start from a coupling matrix synthesis or a circuit theory-based model of the filter. A complete model of the filter can then be rapidly built using a new library of filter building blocks in Cadence  AWR Design Environment platform, specifically Analyst™ electromagnetic (EM) simulation software. The library supports both rectangular and circular cavities with many different resonator geometries. Finally, using port tuning techniques, the geometry of the filter can be fine-tuned before the first prototype is built. Presented by: Dan Swanson, DGS Associates dgsboulder.com/