We have designed a miniaturized high-temperature superconducting dual-band bandpass filters (DBPFs) using stubloaded meander line resonators and their applications to tri-band bandpass filters (TBPFs). The DBPF enables independent control of the center frequencies of the first and second bands. The bandwidths of the DBPF can be flexibly adjusted using a capacitance-loaded microstrip line between the resonators. The DBPF was designed and analyzed using an electromagnetic simulator and fabricated using an YBa 2 Cu 3 O y thin film on an Al 2 O 3 substrate. The center frequencies are 3.5 and 5.0 GHz; two bands have 2% bandwidth. The measured frequency responses of the DBPF were in good agreement with the simulated frequency responses. The TBPF was realized by combining the DBPF and a single-band bandpass filter (SBPF) that uses a folded stepped-impedance resonator with common input and output. The DBPF constructs the first and third bands of 3.5 and 5.0 GHz, and the SBPF forms the second band of 4.25 GHz. The frequency responses of the simulated TBPF meet the design parameters.Index Terms-Dual-band bandpass filter, HTS filter, stubloaded resonator, tri-band bandpass filter.
Nd 2 Fe 14 B molten alloy droplets were containerlessly solidified using a 25 m drop tube. The relationship between the sample diameter and the microstructure was investigated. The diameter of the resultant spherical samples was in range of 150 to 2000 mm. When sample diameter was larger than 500 mm, the microstructure of the spherical sample consisted of the -Fe phase embedded in matrix of the Nd 2 Fe 14 B phase within entire sections. In the spherical sample with diameter of 400 mm, the microstructures consisted of two regions, one was columnar grains of the Nd 2 Fe 14 B phase and the other was -Fe phase embedded in matrix of the Nd 2 Fe 14 B phase. The columnar Nd 2 Fe 14 B region expanded as the sample diameter decreased from 400 to 350 mm. When sample diameter reduced to 250 mm, the microstructure of a spherical sample consisted of the pure dendritic Nd 2 Fe 14 B phase without any -Fe phase.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.