A compact size and wide stopband microstrip quadruplexer with a common crossed resonator is proposed in this paper. The resonator mentioned is theoretically analyzed and proved to be able to resonance at three different frequencies, which can be easily modified by changing the length of the corresponding stub of the resonator. This tri-mode resonator is proved to have the capacity of being shared by three different bandpass filters in a quadruplexer in this paper. Then an additional channel is designed to be coupled to the other side of the feed line of the common input port. Compared to conventional ones, the proposed quadruplexer has a more compact structure, cause no extra matching network is needed, and the number of resonators is reduced effectively. Moreover, a wide stopband is obtained by making the resonators work at the same fundamental frequencies but different higher order frequencies. Besides, open circuit stubs are also used to suppress the harmonic frequencies. To demonstrate the design procedure, a quadruplexer with a third order Chebyshev response in each channel is fabricated and measured. The measured result is in good agreement with the simulated one, showing an attenuation of 20 dB up to 10.16 times of the first channel frequency.
2. Shi, J., J.-X. Chen, and Z.-H. Bao, "Diplexers based on microstrip line resonators with loaded elements," Progress In Electromagnetics Research, Vol. 115, 423-439, 2011.
doi:10.2528/PIER11031516
3. Lin, S.-C. and C. Y. Yeh, "Design of microstrip triplexer with high isolation based on parallel coupled-line filters using T-shaped short-circuited resonators," IEEE Microw. Wireless Compon. Lett., Vol. 25, 648-650, 2015.
doi:10.1109/LMWC.2015.2463215
4. Deng, P.-H., B.-L. Huang, and B.-L. Chen, "Designs of microstrip four- and five-channel multiplexers using branch-line-shaped matching circuits," IEEE Trans. Compon. Packag. Manuf. Technol., Vol. 5, 1331-1338, 2015.
doi:10.1109/TCPMT.2015.2463739
5. Zeng, S.-J. and J.-Y. Wu, "Compact and high-isolation quadruplexer using distributed coupling tachnique," IEEE Microw. Wireless Compon. Lett., Vol. 21, 197-199, 2011.
doi:10.1109/LMWC.2011.2109702
6. Weng, S.-C., K. W. Hsu, and W.-H. Tu, "Microstrip bandpass single-pole quadruple-throw switch and independently switchable quadruplexer," IEEE Trans. Ante. Propag., Vol. 8, 244-254, 2014.
7. Wu, H.-W., S.-H. Huang, and Y.-F. Chen, Compact microstrip triplexer based on coupled stepped impedance resonators, IEEE MTT-S Int. Microw. Symp. Dig., 1-3, 2013.
8. Hung, W.-C., K. W. Hsu, and W.-H. Tu, Wide-stopband microstrip quadruplexer using asymmetric stepped-impedance resonators, IEEE MTT-S Int. Microw. Symp. Dig., 1-4, 2013.
9. Chen, C.-F., T.-Y. Huang, C.-P. Chou, and R.-B. Wu, "Microstrip diplexers design with common resonator sections for compact size, but high isolation," IEEE Trans. Microw. Theory Tech., Vol. 54, 1945-1952, 2006.
doi:10.1109/TMTT.2006.873613
10. Tantiviwat, S., N. Intarawiset, and R. Jeenawong, Wide-stopband, compact microstrip diplexer with common resonator using stepped-impedance resonators, IEEE Tencon. Spring Conf., 17-19, 2013.
11. Chuang, M.-L. and M. T. Wu, "Microstrip diplexer design using common T-shaped resonator," IEEE Microw. Wireless Compon. Lett., Vol. 21, 583-585, 2011.
doi:10.1109/LMWC.2011.2168949
12. Chen, C.-F., T.-Y. Huang, T.-M. Shen, and R.-B. Wu, A miniaturized microstrip common resonator triplexer without extra matching network, Asia Europe Microw. Conf., 1439-1442, 2006.
13. Chu, Q.-X., F.-C. Chen, and Z.-H. Tu, "A novel crossed resonator and its applications to bandpass filters," IEEE Trans. Microw. Theory Tech., Vol. 57, 1753-1759, 2009.
doi:10.1109/TMTT.2009.2022873
14. Chen, C.-F., T.-Y. Huang, C.-P. Chou, and R.-B. Wu, "Design of microstrip bandpass filters with multiorder spurious-mode suppression," IEEE Trans. Microw. Theory Tech., Vol. 53, 3788-3793, 2005.
doi:10.1109/TMTT.2005.859869
15. Chen, F.-C., R.-S. Li, and Q.-X. Chu, "Ultra-wide stopband low-pass filter using multiple transmission zeros," IEEE Access, Vol. 5, 6437-6443, 2017.
16. Hong, J. S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, Wiley, New York, 2001.
doi:10.1002/0471221619
Submit
