Controllable miniature tri-band bandpass filter using defected microstrip structure

A multi-band microwave filter design method by using the defected microstrip structure (DMS) is developed. A new DMS bandpass filter with a tri-band is designed, fabricated and measured, and the experiment demonstrates the new proposal. The new DMS filter has the advantages of a compact and simple circuit topology, miniature circuit size, individually controllable centre frequencies and individually tunable bandwidths.