TY - JOUR
T1 - Bandwidth tuning of resonator filter using reduced number of tunable coupling structures
AU - Lee, Boyoung
AU - Nam, Seunggoo
AU - Lee, Juseop
N1 - Funding Information:
Manuscript received August 18, 2018; revised December 11, 2018; accepted January 2, 2019. Date of publication February 26, 2019; date of current version April 3, 2019. This work was supported by the Korea Government (Ministry of Science and ICT) through the National Research Foundation of Korea under Grant NRF-2018R1A2B6006095. (Corresponding author: Juseop Lee.) The authors are with the College of Informatics, Korea University, Seoul 02841, South Korea (e-mail: juseoplee@gmail.com).
PY - 2019/4
Y1 - 2019/4
N2 - This paper presents a new bandwidth tuning theory for Butterworth-response resonator filters. The presented theory shows that the bandwidth of odd-order Butterworth filters can be varied by adjusting only two interresonator coupling structures while maintaining a perfect impedance matching at the center frequency. In other words, this paper presents an analytic approach to reduce the number of tunable coupling structures when designing a bandwidth-tunable resonator filter. Theories for third- A nd fifth-order direct-coupled filters are discussed in detail, and it is shown that only two interresonator coupling structures are required to be tunable. In addition, for verifying the new bandwidth tuning method, a fifth-order cylindrical cavity filter has been designed, fabricated, and measured. The fabricated filter has an 11:1 bandwidth tuning range.
AB - This paper presents a new bandwidth tuning theory for Butterworth-response resonator filters. The presented theory shows that the bandwidth of odd-order Butterworth filters can be varied by adjusting only two interresonator coupling structures while maintaining a perfect impedance matching at the center frequency. In other words, this paper presents an analytic approach to reduce the number of tunable coupling structures when designing a bandwidth-tunable resonator filter. Theories for third- A nd fifth-order direct-coupled filters are discussed in detail, and it is shown that only two interresonator coupling structures are required to be tunable. In addition, for verifying the new bandwidth tuning method, a fifth-order cylindrical cavity filter has been designed, fabricated, and measured. The fabricated filter has an 11:1 bandwidth tuning range.
KW - Bandwidth tuning
KW - cavity resonator
KW - interresonator coupling
KW - topology
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U2 - 10.1109/TMTT.2019.2898860
DO - 10.1109/TMTT.2019.2898860
M3 - Article
AN - SCOPUS:85064076996
VL - 67
SP - 1496
EP - 1503
JO - IEEE Transactions on Microwave Theory and Techniques
JF - IEEE Transactions on Microwave Theory and Techniques
SN - 0018-9480
IS - 4
M1 - 8653495
ER -