The Journal of Korean Institute of Electromagnetic Engineering and Science (한국전자파학회논문지)

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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Compact Cascaded Quadruplet Bandpass Filter Using Modified Coaxial Cavity Resonator with Q-Factor Improvement

품질계수가 향상된 변형된 동축 공동 공진기를 이용한 다단 Quadruplet 대역통과 여파기

  • 장건호 ((주)케이엠더블유 통신연구소) ;
  • 왕욱광 ((주)케이엠더블유 통신연구소) ;
  • 이보람 ((주)케이엠더블유 통신연구소) ;
  • 박남신 ((주)케이엠더블유 통신연구소)
  • Received : 2015.07.07
  • Accepted : 2015.11.19
  • Published : 2015.11.30
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Abstract

This paper presents a novel modified coaxial cavity resonator and its application to bandpass filters with compact size and improved quality factor(Q-factor). The proposed resonator is made up of ${\Gamma}-shape$ or curved four inner conductive posts within a single cavity, which provides quadruplet to realize bandpass filter. No metallic walls inside the cavity are required, and thus the utilization efficiency of the cavity space is improved. As a result, the unloaded Q can be approximately 15 % higher in comparison to the conventional coaxial resonator, or more than 35 % volume saving can be achieved while maintaining the similar Q-factor value with the conventional designs. In addition, due to the multiple cross-coupling occurring within the cavity, including the source-to-load coupling, four flexible transmission zeros can be created to realize different filtering functions. Simulations as well as experimental results of four- and eight-pole filters are presented to validate this attractive design concept. Good agreement between measured and computed results is obtained.

본 논문에서는 새로운 변형된 동축 공동 공진기를 제안하고, 대역통과 여파기를 설계한다. 제안된 공진기는 하나의 캐비티 내부에 ${\Gamma}$-형 또는 곡선형의 4개의 접지된 도체 포스트로 구성되어 있다. 일반 동축 공동 공진기 여파기와 달리 도체 벽이 없기 때문에 공간 효율이 개선되어 품질계수가 약 15 % 이상 향상되며, 동일한 품질계수 대비 35 % 이상의 크기 소형화가 가능하다. 또한, 인접하지 않은 공진기와 입출력 교차결합을 통해 4개의 조절 가능한 전송영점이 생성되어 차단대역의 감쇄특성을 향상시킬 수 있다. 제안된 여파기와 설계법은 모의실험과 제작 및 측정을 통해 검증되었다.

Keywords

References

  1. C. Wang, K. A. Zaki, "Dielectric resonators and filters", IEEE Microw. Mag., vol. 8, no. 5, pp. 115-127, Oct. 2007. https://doi.org/10.1109/MMM.2007.903648
  2. S. J. Fiedziuszko, I. C. Hunter, T. Itoh, Y. Kobayashi, T. Nishikawa, S. N. Stitzer, and K. Wakino, "Dielectric materials, devices, and circuits", IEEE Trans. Microw. Theory Techn., vol. 50, no. 3, pp. 706-720, Mar. 2002. https://doi.org/10.1109/22.989956
  3. M. Memarian, R. R. Mansour, "Quad-mode and dualmode dielectric resonator filters", IEEE Trans. Microw. Theory Techn., vol. 57, no. 12, pp. 3418-3426, Dec. 2009. https://doi.org/10.1109/TMTT.2009.2034310
  4. 장건호, 박남신, 김병철, 이돈용, 원정희, 왕욱광, "원통형 삼중모드 유전체 공진기를 이용한 대역 통과 여파기의 설계", 한국전자파학회논문지 26(1), pp. 30-38, 2015년 1월. https://doi.org/10.5515/KJKIEES.2015.26.1.30
  5. G. L. Matthaei, "Comb-line band-pass filters of narrow or moderate bandwidth", Microw. J., vol. 6, pp. 82-91, Aug. 1963.
  6. R. J. Wenzel, "Synthesis of combline and capacitively loaded interdigital bandpass filters of arbitrary bandwidth", IEEE Trans. Microw. Theory Techn., vol. MTT-19, no. 8, pp. 678-686, Aug. 1971. https://doi.org/10.1109/TMTT.1971.1127609
  7. R. J. Cameron, C. M. Kudsia, and R. R. Mansour, Microwave Filters for Communication Systems: Fundamentals, Design, and Applications, New York, NY, USA: Wiley, 2007.
  8. R. R. Mansour, "Filter technologies for wireless base stations", IEEE Microw. Mag., vol. 5, no. 1, pp. 68-74, Mar. 2004. https://doi.org/10.1109/MMW.2004.1284945
  9. M. El Sabbagh, K. A. Zaki, H. W. Yao, and M. Yu, "Full-wave analysis of coupling between combline resonators and its application to combline filters with canonical configurations", IEEE Trans. Microw. Theory Techn., vol. 49, no. 12, pp. 2384-2393, Dec. 2001. https://doi.org/10.1109/22.971625
  10. A. R. Harish, J. S. K. Raj, "A direct method to compute the coupling between nonidentical microwave cavities", IEEE Trans. Microw. Theory Techn., vol. 52, no. 12, pp. 2645-2650, Dec. 2004. https://doi.org/10.1109/TMTT.2004.837311
  11. A. Morini, G. Venanzoni, and T. Rozzi, "A new adaptive prototype for the design of side-coupled coaxial filters with close correspondence to the physical structure", IEEE Trans. Microw. Theory Techn., vol. 54, no. 3, pp. 1146-1153, Mar. 2006. https://doi.org/10.1109/TMTT.2005.864112
  12. R. J. Cameron, "Advanced filter synthesis", IEEE Microw. Mag., vol. 12, no. 6, pp. 42-61, Oct. 2011. https://doi.org/10.1109/MMM.2011.942007
  13. J. B. Thomas, "Cross-coupling in coaxial cavity filterstutorial overview", IEEE Trans. Microw. Theory Techn., vol. 51, no. 4, pp. 1368-1376, Apr. 2003. https://doi.org/10.1109/TMTT.2003.809180
  14. H. Wang, Q. X. Chu, "An inline coaxial quasi-elliptic filter withn controllable mixed electric and magnetic coupling", IEEETrans. Microw. Theory Techn., vol. 57, no. 3, pp. 667-673, Mar. 2009. https://doi.org/10.1109/TMTT.2009.2013290
  15. Y. Wang, M. Yu, "True inline cross-coupled coaxial cavity filters", IEEE Trans. Microw. Theory Techn., vol. 57, no. 12, pp. 2958-2965, Dec 2009. https://doi.org/10.1109/TMTT.2009.2034221
  16. E. J. Naglich, J. Lee, H. H. Sigmarsson, D. Peroulis, and W. J. Chappell, "Intersecting parallel-plate wave-guide loaded cavities for dual-mode and dual-band filters", IEEE Trans. Microw. Theory Techn., vol. 61, no. 5, pp. 1829-1838, May 2013. https://doi.org/10.1109/TMTT.2013.2255887
  17. 장건호, 강승택, "변형된 원형 버섯 구조의 0차 공진을 이용한 메타 재질 대역 통과 여파기의 설계", 한국전자파학회논문지 21(8), pp. 893- 899, 2010년 8월. https://doi.org/10.5515/KJKIEES.2010.21.8.893
  18. S. Bastioli, R. Snyder, "Evanescent mode filters using strongly-coupled resonator pairs", in IEEE MTT-S Int. Microw. Symp. Dig., 2013.
  19. Mo Hoft, S. Buerger, "Q-factor improvement of combline resonators", German Microwave Conferenece, UIm, Germany, pp. 53-56. Apr. 2005.
  20. C. Liao, C. Chang, "Design of microstrip quadruplet filters with source-load coupling", IEEE Trans. Theory Techn., vol. 53, no. 7, pp. 2302-2308, Jul. 2005. https://doi.org/10.1109/TMTT.2005.850442
  21. S. Amari, U. Rosenberg, and J. Bornemann, "Adaptive synthesis and design of resonator filters with source/load-multi resonator coupling", IEEE Trans. Microw. Theory Techn., vol. 50, no. 8, pp. 1969-1978, Aug. 2002. https://doi.org/10.1109/TMTT.2002.801348