Design of the UWB BandPass Filter of Microstrip CRLH-TL Metamaterial Cell Type with Improved Rejection Performance

저지특성이 향상된 CRLH-TL Metamaterial 쎌 형 UWB 대역통과여파기의 설계

  • Kahng, Sung-Tek (Dept. of Information & Telecommunication Engineering, University of Incheon) ;
  • Ju, Jeong-Ho (Electronics and Telecommunications Research Institute)
  • Published : 2008.08.25

Abstract

In order to enhance the rejection performance of the UWB bandpass filter based on the Composite Right- and Left-Handed Transmission-line(CRLH-TL) Metamaterial cell, we propose the lowpass filtering concept that fits into the design objectives : Keeping metamaterial property and miniaturization. So the bandpass filter itself is made far less than a quarter-wavelength and a pair of symmetric comprises lowpass filtering blocks are placed before and after the center CRLH filter which comprises tile interdigitated coupled lines and short-circuited stob. The design result will show the size of 'guided wavelength/8', the fractional bandwidth over 100%, the insertion loss much less than 1 dB, a flat Group-Delay and a good return loss performance, as expected.

좌우현 합성 선로 메타재질구조 쎌 형식인 UWB 대역통과여파기의 저지특성을 향상시키기 위해, 메타재질특성을 유지하면서도 소형화라는 설계목적에 적합한 저역통과여파기 개념을 제안한다. 따라서 대역통과여파기 자체는 파장의 0.25배보다 훨씬 작게 만들어지고, 이는 인터디지틀 결합기와 접지된 스텁으로 구성되며, 전후에 대칭형 소형 저역통과 블록을 가진다. 설계결과는, 예상대로, 관내파장의 1/8의 크기, 대역폭 100%, 1dB 이하의 삽입손실, 평탄한 군지연, 우수한 반사손실 특성을 보인다.

Keywords

References

  1. H. Ishida, and K. Araki, 'Design and Analysis of UWB Bandpass Filter with Ring Filter,' in IEEE MTT-S Intl. Dig. June 2004 pp. 1307-1310
  2. H. Wang, L. Zhu and W. Menzel, 'Ultra-Wideband Bandpass Filter with Hybrid Microstrip/CPW Structure,'IEEE Microwave And Wireless Components Letters, vol. 15, pp. 844-846, December 2005 https://doi.org/10.1109/LMWC.2005.860016
  3. S. Sun, and L. Zhu, 'Capacitive-Ended Interdigital Coupled Lines for UWB Bandpass Filters with Improved Out-of-Band Performances,' IEEE Microwave And Wireless Components Letters, vol. 16, pp. 440-442, August 2006 https://doi.org/10.1109/LMWC.2006.879492
  4. W. Menzel, M. S. R. Tito, and L. Zhu, 'Low-Loss Ultra-Wideband(UWB) Filters Using Suspended Stripline,'in Proc. Asia-Pacific Microw. Conf. , Dec. 2005, vol. 4, pp.2148-2151
  5. C.-L. Hsu, F.-C. Hsu, and J.-T. Kuo, 'Microstrip Bandpass Filters for Ultra- Wideband(UWB) Wireless Communications,' in IEEE MTT-S Intl. Dig. , June 2005, pp.675-678
  6. C. Caloz and T. Itoh, Electromagnetic Metamaterials : Transmission Line Theory and Microwave Applications, WILEY-INTERSCIENCE, John-Wiley & Sons Inc., Hoboken, NJ 2006
  7. S. Kahng, and J. Ju, 'Left-Handedness based Bandpass Filter Design for RFID UHF-Band applications,' in Proc. KJMW 2007, Nov.. 2007, vol. 1, pp.165-168
  8. J. Ju and S. Kahng, 'Design of the Miniaturaized UHF Bandpass Filter with the Wide Stopband using the Inductive-Coupling Inverters and Metamaterials,' in Proc. Korea Electromagnetic Engineering Society Conference 2007, Nov. 2007, vol. 1, pp.5-8
  9. J. Ju and S. Kahng, 'Design of the Miniaturized UWB BandPass Filter Using the 1 Unit of CRLH-TL,' Korean Institute of Electromagnetic Engineering and Science Journal(Korean), Vol. 18, No. 12, pp. 1402-1407, December 2007 https://doi.org/10.5515/KJKIEES.2007.18.12.1402
  10. K. C. Gupta, R. Garg, I. Bahl, and P. Bhartia, Microstrip Lines and Slotlines, Artech House Inc., Norwood, MA 1996