Design of Ultra-Wideband (UWB) Bandpass Filters Based on Interdigital Edge Coupled Lines: A Review

Since several decades ago, parallel coupled lines have found an extensive range of applications in order to design microwave circuits such us filter, impedance transformers and couplers. It gives advantages term low cost, easier integration with other devices controllable performances by changing coupling coefficient between lines. This paper presents a review two three interdigital bandpass filters for ultra-Wideband (UWB) communication systems during previous years achieve fraction passband from 3.1 GHz 10.6 then FBW that can reach 109%. Different structures as multiple-mode resonator, Short Circuited Stubs, Open stub, Stepped-impedance resonators Rectangular Ring been reportedly used ameliorate the developed filters.