Compact Tunable Filters for Broadband Applications

AbstractMicrowave filters are essential components of modern communication systems. Miniaturization of microwave filters is of much demand in today's rapidly changing communication world with ever more growing wireless applications. The paper presents compact tunable band pass filters to provide multiple bands of operation. The filter employs tunable/chip inductors along with an inter-digital coupled line for introducing transmission zeros on both band edges. Tunability is achieved by varying the inductor values. The stop band attenuation is improved by etching Complementary Split Ring Resonators (CSRR's) and Defected Ground Structures (DGS) in the ground plane