2017-02-19
A 70 MHz ~270 MHz Electrical Tunable LC Bandpass Filter Based on Mixed Coupling and Cross-Coupling
By
Progress In Electromagnetics Research Letters, Vol. 66, 45-51, 2017
Abstract
This paper presents an electrical tunable bandpass filter based on tunable LC resonators loaded with semiconductor varactors. Magnetic dominated mixed coupling between the tunable resonators is utilized to compensate the bandwidth of the tunable filter. Cross coupling is created by using magnetic dominated mixed coupling between the resonators and source to load electrical coupling, and two transmission zeros are generated beside the pass band. The tunable mechanism of the proposed filter is studied. The tunable filter is analyzed, designed, fabricated and measured. The measurement shows that the filter can be tuned from 70 MHz to 270 MHz with a fractional bandwidth from 27% to 21%.
Citation
Linzhi Liu, Qian-Yin Xiang, Xiangrong Hu, Zongliang Zheng, Zhixiong Di, and Quanyuan Feng, "A 70 MHz ~270 MHz Electrical Tunable LC Bandpass Filter Based on Mixed Coupling and Cross-Coupling," Progress In Electromagnetics Research Letters, Vol. 66, 45-51, 2017.
doi:10.2528/PIERL16120104
References

1. Xiang, Q., Q. Feng, X. Huang, and D. Jia, "Electrical tunable microstrip LC bandpass filters with constant bandwidth," IEEE Transactions on Microwave Theroy and Techniques, Vol. 61, No. 3, 1124-1130, Mar. 2013.
doi:10.1109/TMTT.2013.2241781        Google Scholar

2. Rais-Zadeh, M., J. T. Fox, D. D. Wentzloff, and Y. B. Gianchandani, "Reconfigurable radios: A possible solution to reduce entry costs in wireless phones," Proceedings of the IEEE, Vol. 103, No. 3, 438-451, Mar. 2015.
doi:10.1109/JPROC.2015.2396903        Google Scholar

3. Fu, M.-Y., Q.-Y. Xiang, D. Zhang, D.-Y. Tian, and Q.-Y. Feng, "A UHF third order 5-bit digital tunable bandpass filter based on mixed coupled open ring resonators," Progress In Electromagnetics Research C, Vol. 64, 89-96, May 2016.
doi:10.2528/PIERC16032701        Google Scholar

4. Gao, L., X. Y. Zhang, and Q. Xue, "Compact tunable filtering power divider with constant absolute bandwidth," IEEE Transactions on Microwave Theory and Techniques, Vol. 63, No. 10, 3505-3513, Oct. 2015.
doi:10.1109/TMTT.2015.2454731        Google Scholar

5. Liang, F., X. Zhai, W. Lu, Q. Wan, and Y. Zhang, "An independently tunable dual-band filter using asymmetric λ/4 resonator pairs with shared via-hole ground," Progress In Electromagnetics Research, Vol. 146, 99-108, 2014.
doi:10.2528/PIER14032505        Google Scholar

6. Xiang, Q.-Y., Q.-Y. Feng, X.-G. Huang, and D.-H. Jia, "Tunable bandstop filter with bandwidth compensation," Applied Computational Electromagnetics Society Journal, Vol. 30, No. 8, 903-908, 2015.        Google Scholar

7. Xiang, Q.-Y., Q.-Y. Feng, X.-G. Huang, and D.-H. Jia, "A novel microstrip LC reconfigurable bandpass filter," Progress In Electromagnetics Research Letters, Vol. 36, 171-179, 2013.
doi:10.2528/PIERL12111202        Google Scholar

8. Wang, Y., F. Wei, H. Xu, and X.-W. Shi, "A tunable 1.4-2.5 GHz bandpass filter based on single mode," Progress In Electromagnetics Research, Vol. 135, 261-269, 2013.
doi:10.2528/PIER12111704        Google Scholar

9. Liang, F., W. Cai, W. Lu, L. Deng, and X. Zhai, "An independently tunable dual-band bandpass filter using a center shorting-stub-loaded resonator," Progress In Electromagnetics Research C, Vol. 67, 31-40, 2016.
doi:10.2528/PIERC16053102        Google Scholar

10. Ma, Y.-L., W. Che, J.-X. Chen, and W. Feng, "High selectivity balanced bandpass filter with tunable bandwidth using stub-loaded resonator," Progress In Electromagnetics Research Letters, Vol. 55, 89-95, 2015.
doi:10.2528/PIERL15052804        Google Scholar

11. Mohammadi, L. and K.-J. Koh, "2-4 GHz Q-tunable LC bandpass filter with 172-dBHz peak dynamic range, resilient to +15-dBm out-of-band blocker," 2015 IEEE Custom Integrated Circuits Conference (CICC), 1-4, 2015.        Google Scholar

12. Mohieldin, A. N., E. Sanchez-Sinencio, and J. Silva-Martinez, "A 2.7 V, 1.8 GHz, 4th order tunable LC bandpass filter with ±0.25 dB passband ripple," Proceedings of the 28th European Solid-State Circuits Conference, 343-346, Sep. 2002.        Google Scholar

13. Zeng, K., D. Psychogiou, and D. Peroulis, "A VHF tunable lumped-element filter with mixed electric-magnetic couplings," 2015 IEEE 16th Wireless and Microwave Technology Conference, 1-4, Apr. 2015.        Google Scholar

14. Mohieldin, A. N., E. Sanchez-Sinencio, and J. Silva-Martinez, "A 2.7-V 1.8-GHz fourth-order tunable LC bandpass filter based on emulation of magnetically coupled resonators," IEEE Journal of Solid-State Circuits, Vol. 38, No. 7, 1172-1181, Jul. 2003.
doi:10.1109/JSSC.2003.813228        Google Scholar

15. Testi, N., R. Berenguer, X. Zhang, S. Munoz, and Y. Xu, "A 2.4 GHz 72 dB-variable-gain 100 dB-DR 7.8 mW 4th-order tunable Q-enhanced LC band-pass filter," 2015 IEEE Radio Frequency Integrated Circuits Symposium (RFIC), 87-90, Nov. 30, 2015.        Google Scholar

16. Chen, C.-H., C.-H. Huang, T.-S. Horng, S.-M. Wu, J. Chen, C. T. Chiu, and C. P. Hung, "A novel compact LC resonator-based bandpass filter design with tunable transmission zeros," 2008 Asia-Pacific Microwave Conference, 1-4, 2008.        Google Scholar

17. Lee, H. S., D. H. Choi, and J. B. Yoon, "MEMS-based tunable LC bandstop filter with an ultra-wide continuous tuning range," IEEE Microwave and Wireless Components Letters, Vol. 19, No. 11, 710-712, Nov. 2009.        Google Scholar

18. Wong, S.-W., R.-S. Chen, J.-Y. Lin, L. Zhu, and Q.-X. Chu, "Substrate integrated waveguide quasi-elliptic filter using slot-coupled and microstrip-line cross-coupled structures," IEEE Transactions on Components, Packaging and Manufacturing Technology, 1-8, Nov. 2016.        Google Scholar

19. Ding, J., D. Liu, S. Shi, and W. Wu, "W-band quasi-elliptical waveguide filter with cross-coupling and source-load coupling," Electronics Letters, Vol. 52, No. 23, Nov. 2016.        Google Scholar

20. Chiou, Y. C. and G. M. Rebeiz, "A quasi elliptic function 1.75–2.25 GHz 3-pole bandpass filter with bandwidth control," IEEE Transactions on Microwave Theory and Techniques, Vol. 60, No. 2, 244-249, Feb. 2012.
doi:10.1109/TMTT.2011.2178260        Google Scholar

21. Hong, J.-S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, John Wiley & Sons, Inc., 2001.
doi:10.1002/0471221619

22. Zhou, W. J. and J. X. Chen, "High-selectivity tunable balanced bandpass filter with constant absolute bandwidth," IEEE Transactions on Circuits and Systems II: Express Briefs, 2017 (IEEE Early access paper).        Google Scholar

23. Thomas, J. B., "Cross-coupling in coaxial cavity filters - A tutorial overview," IEEE Transactions on Microwave Theory and Techniques, Vol. 51, No. 4, 1368-1376, Apr. 2003.
doi:10.1109/TMTT.2003.809180        Google Scholar