Bandwidth-enhanced lumped-element absorptive bandstop filter topology and its application to LTCC bandstop filter design. Issue 6 (27th August 2014)

• Record Type: Journal Article
• Authors: Lee, Juseop; Kim, Byungguk; Lee, Kangho; Chappell, William J.
• Is Part Of: International journal of microwave and wireless technologies. Volume 7:Issue 6(2015)
• Page Start: 691
• Page End: 698
• Publication Date: 2014-08-27
• Subjects: Filters, -- Passive components and circuits; Wireless communication systems -- Periodicals; Microwave circuits -- Periodicals; Radio frequency -- Periodicals; 621.381305
• DOI: 10.1017/S1759078714001147
• Languages: English
• ISSNs: 1759-0787

Abstract

Abstract : In this paper, we show a second-order (four-resonator) absorptive bandstop filter circuit topology which gives a larger bandwidth compared to a first-order topology. Due to the absorptive characteristic, it creates a large attenuation at the center frequency using low-Q resonators. Since low-Q resonators can be used in generating a large attenuation, small-size resonators can be employed in bandstop filter design. Analytic design equations are provided so that a higher-order absorptive bandstop filter can be designed analytically. It is also shown that the second-order filter topology exhibits a better frequency selectivity having a same bandwidth. The proposed filter topology has been applied to a design of a miniaturized low-temperature co-fired ceramic bandstop filter with low-Q resonators. The Q-factor of the lumped-element resonators has been chosen to be 5 for demonstration.