High Selectivity and Flat Group Delay ParallelCoupled Microstrip Bandpass Filter with Lumped Element K-Inverters

Abstract

In this paper, high selectivity and flat group delay parallel-coupled microstrip bandpass filter with lump element Kinverter are proposed. By using delay line, cross coupling is introduced and controlled easily to generate finite transmission zeros for selectivity and flat group delay. Finally, 5th-order and 6th-order filters with high selectivity and flat group delay are given as examples.