Design and implementation of compact and reconfigurable planar filters is one of the most valuable and exciting experiences in my education. The knowledge I learned and confidence I gained during the studying years will be beneficial to my whole life. This work introduces the investigation and development of design methodologies for the creation of multi-functional bandpass filters and lowpass filters at microwave frequencies. These filters are capable of tuning to different frequency bands as well as varying their fractional bandwidth. The work presented here relates to the evolving multifunction philosophy of RF systems. This work presents a comprehensive study of RF reconfigurable planar microwave filters, which generate reliable and scalable filter topologies with tunable properties.