A very compact filter using defected microstrip structure with Island

Designing filters at lower microwave frequencies, is usually accompanied with increase in total dimensions of the filter structure. To remedy this problem, a novel structure called Island Defected Microstrip structure (I-DMS) is proposed. Using I-DMS, it is possible to obtain a compact filter which can be easily integrated with the other microwave devices and circuits while keeping the total size of the system as minimum as possible. This design is obtained based on extreme cases of DMS dimensions. Finally the application of the proposed filter in wide-open warfare systems is demonstrated. The resonance frequency has decreased 6 times without any change in the size of the primary structure.