COMPACT DESIGN OF MILLIMETER WAVE BANDPASS FILTERS WITH THREE COUPLED FINLINE AND DIFFERENT COMBINATIONS OF SPLIT RING RESONATORS

This paper presents of new concept of the design multi band pass filters with three parallel coupled finline structure and metamaterials. Ultra-Wide Band (UWB) filter of third order having center frequency of 10 GHz with fractional bandwidth of 20 % have been designed. A design graph has been presented here for symmetric three unilateral finline structures to design ultra-wide bandpass filter parameters like resonators length (l), width (w) and spacing(s) between them. We have explored the electromagnetic characterization of artificial magnetic materials (Metamaterials) for converting this ultra-wide bandpass filter in to multi bandpass filters. This ultra-wide bandpass filter have been converted in to different bandpass filters i.e. dual bandpass, triple bandpass, quad bandpass, and five bandpass filters with different combinations and orientations of Split Ring Resonators (SRR). These designed filters have been simulated with High Frequency Structure Simulator (HFSS), and found interesting results with low insertion loss and sharp return loss. This paper proposes structure for ultra-wide band (UWB) and multi bandpass filters for different RF and Microwave applications. The desired signals must be transmitted with minimum loss, while unwanted frequencies must be strongly attenuated.