PIER Letters
 
Progress In Electromagnetics Research Letters
ISSN: 1937-6480
Home | Search | Notification | Authors | Submission | PIERS Home | EM Academy
Home > Vol. 33 > pp. 131-140

FREQUENCY-TUNABLE BANDPASS FILTERS WITH CONSTANT ABSOLUTE BANDWIDTH AND IMPROVED LINEARITY

By F. L. Yu, X. Y. Zhang, and Y. B. Zhang

Full Article PDF (421 KB)

Abstract:
This paper presents a frequency-tunable bandpass filter with constant absolute bandwidth and improved linearity. The proposed resonator is composed of an open-ended transmission line with back-to-back varactor diodes loaded at one end. The back-to-back varactor diodes are used to enhance the linearity of the filter, which is better than that of the single varactor counterparts. A mixed electric and magnetic coupling scheme is utilized to control the overall coupling coefficients so that the absolute bandwidth can be kept constant when the frequency is tuned. For validation, two frequency-tuning filters with 30-MHz and 44-MHz absolute bandwidth are implemented. The experimental and simulated results are presented to verify the proposed design.

Citation:
F. L. Yu, X. Y. Zhang, and Y. B. Zhang, "Frequency-Tunable Bandpass Filters with Constant Absolute Bandwidth and Improved Linearity," Progress In Electromagnetics Research Letters, Vol. 33, 131-140, 2012.
doi:10.2528/PIERL12061006

References:
1. Li, L. and D. Uttamchandani, "Demonstration of a tunable RF MEMS bandpass filter using silicon foundry process," Journal of Electromagnetic Waves and Applications, Vol. 23, No. 2--3, 405-413, 2009.
doi:10.1163/156939309787604355

2. Sekar, V., M. Armendariz, and K. Entesari, "A 1.2--1.6-GHz substrate-integrated-waveguide RF MEMS tunable filter," IEEE Trans. Microw. Theory Tech., Vol. 59, No. 4, 866-876, Apr. 2011.
doi:10.1109/TMTT.2011.2109006

3. Mi, X. Y., O. Toyoda, S. Ueda, and F. Nakazawa, "Miniaturized microwave tunable bandpass filters on high-k LTCC," Proc. Asia-Pac. Microw. Conf. (APMC), 139-142, 2010.

4. Wang, S. and R. X. Wang, "A tunable bandpass filter using Q-enhanced and semi-passive inductors at S-band in 0.18 CMOS," Progress In Electromagnetics Research B, Vol. 28, 55-73, 2011.

5. Kumngern, M. and K. Dejhan, "Electronically tunable voltage-mode universal filter with three-input single-output," Internal Conference on Electronic Devices, Systems and Applications (ICEDSA), 7-10, Apr. 2010.
doi:10.1109/ICEDSA.2010.5503113

6. Long, J., C. Z. Li, W. Z. Cui, J. T. Huangfu, and L. X. Ran, "A tunable microstrip bandpass filter with two independently adjustable transmission zeros," IEEE Microw. Wireless Compon. Lett., Vol. 21, 74-76, Feb. 2011.

7. Wang, X., P. Bao, T. J. Jackson, and M. J. Lancaster, "Tunable microwave filters based on discrete ferroelectric and semiconductor varactors," IEEE Trans. in Proc. Asia-Pac. Microw. Conf., Vol. 5, No. 7, 776-782, May 2011.

8. Courreges, S., Y. Li, Z. Zhao, K. Choi, A. Hunt, and J. Papapolymerou, "Two-pole X-band-tunable ferroelectric filters with tunable center frequency, fractional bandwidth, and return loss," IEEE Trans. Microw. Theory Tech., Vol. 57, No. 12, 2872-2881, Dec. 2009.
doi:10.1109/TMTT.2009.2034046

9. Courreges, S., Y. Li, Z. Zhao, K. Choi, A. Hunt, and J. Papapolymerou, "A low loss X-band quasi-elliptic ferroelectric tunable filter," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 4, 203-205, Apr. 2009.
doi:10.1109/LMWC.2009.2015494

10. Zhu, Y., R. W. Mao, and C. S. Tsai, "A varactor and FMR-tuned wideband band-pass filter module with versatile frequency tunability," IEEE Trans. Magn., Vol. 47, No. 2, 284-288, Feb. 2011.
doi:10.1109/TMAG.2010.2070836

11. Zhu, Y., G. Qiu, and C. S. Tsai, "A magnetically- and electrically-tunable microwave phase shifter using YIG/GGG thin film," J. of Applied Physics, Vol. 111, 2012.

12. Rebeiz, G. M., RF MEMS: Theory, Design, and Technology, John Wiley & Sons, Feb. 2003.

13. Liu, B., F. Wei, H. Zhang, X. Shi, and H. Lin, "A tunable bandpass filter with switchable bandwidth," Journal of Electromagnetic Waves and Applications, Vol. 25, No. 2--3, 223-232, 2011.
doi:10.1163/156939311794362704

14. Chen, J. X., J. Shi, and Z. H. Bao, "Tunable and switchable bandpass filters using slot-line resonators," Progress In Electromagnetics Research, Vol. 111, 25-41, 2011.
doi:10.2528/PIER10100808

15. Chung, M. S., I. S. Kim, and S. W. Yun, "Varactor-tuned hairpin bandpass filter with enhanced stopband performance," Asia-Pacific Microw. Conf., 645-648, Dec. 2006.
doi:10.1109/APMC.2006.4429503

16. Matthaei, G. L., "Narrow-band, fixed-tuned, and tunable bandpass filters with zig-zag hairpin-comb resonators," IEEE Trans. Microw. Theory Tech., Vol. 51, No. 4, 1214-1219, Apr. 2003.
doi:10.1109/TMTT.2003.809631

17. Pistono, E., L. Duvillaret, J. M. Duchamp, A. Vilcot, and P. Ferrari, "Improved and compact 0.7 GHz tune-all bandpass filter," Electron. Lett., Vol. 43, No. 3, 165-166, Feb. 2007.
doi:10.1049/el:20073085

18. Park, S. J., K. V. Caekenberghe, and G. M. Rebeiz, "A miniature 2.1-GHz low loss microstrip filter with independent electric and magnetic coupling," IEEE Microw. Wireless Compon. Lett., Vol. 14, No. 10, 496-498, Oct. 2004.
doi:10.1109/LMWC.2004.836803

19. Liu, B., F. Wei, Q. Y. Wu, and X. W. Shi, "A tunable bandpass filter with constant absolute bandwidth," Journal of Electromagnetic Waves and Applications, Vol. 25, No. 11--12, 1596-1604, 2011.
doi:10.1163/156939311797164819

20. Zhang, X. Y., C. H. Chan, Q. Xue, and B. J. Hu, "RF tunable bandstop filters with constant bandwidth based on a doublet configuration," IEEE Transactions on Industrial Electronics, Vol. 59, No. 2, 1257-1265, Feb. 2012.
doi:10.1109/TIE.2011.2158038

21. Li, Y. C. and Q. Xue, "Tunable balanced bandpass filter with constant bandwidth and high common-mode suppression," IEEE Trans. Microw. Theory Tech., Vol. 59, No. 10, 2452-2460, Oct. 2011.
doi:10.1109/TMTT.2011.2161325

22. El-Tanani, M. A. and G. M. Rebeiz, "A two-pole two-zero tunable filter with improved linearity," IEEE Trans. Microw. Theory Tech., Vol. 57, No. 4, 830-839, Apr. 2009.
doi:10.1109/TMTT.2009.2015124

23. Ou, Y. C. and G. M. Rebeiz, "Lumped-element fully tunable bandstop filters for cognitive radio applications," IEEE Trans. Microw. Theory Tech., Vol. 59, No. 10, 2461-2468, Oct. 2011.
doi:10.1109/TMTT.2011.2160965

24. Meyer, R. G. and M. L. Stephens, "Distortion in variable-capacitance diodes," IEEE Journal of Solid-State Circuits, Vol. 10, No. 1, 47-54, Feb. 1975.
doi:10.1109/JSSC.1975.1050553


© Copyright 2010 EMW Publishing. All Rights Reserved