The research and development of microwave-tunable equipment has promoted the advancement of electronic countermeasures and electronic surveillance in the field of military communications. The research of fully tunable filters is a hotspot in the field of tunable filter research. Parameters such as center frequency (CF), absolute bandwidth (ABW), and transmission zero (TZ) are important indicators of fully tunable filters. In this paper, a high-performance fully tunable substrate integrated waveguide filter is designed and fabricated to achieve constant ABW (100 MHz) and TZ (1.59 GHz) with CF tunable, and the adjustable range is 1.1-1.3 GHz. Meanwhile, the constant CF (1.15 GHz) is achieved with the ABW tunable, and the adjustable range is 70-120 MHz. Also the constant ABW (100 MHz) and CF (1.14 GHz) are achieved with the TZ tunable, and the adjustable range is 1.59-1.89 GHz. The measured results show that the insertion loss of the tunable filter is lower than 2.04 dB, and the return loss is greater than 20 dB.
2. Zuo, K., et al., "A novel miniaturized quarter mode substrate integrate waveguide tunable filter," IEICE Electronics Express, Vol. 15, No. 7, 1-6, 2018.
doi:10.1587/elex.15.20180013
3. Lan, B., C. Guo, and J. Ding, "A fully tunable two-pole bandpass filter with wide tuning range based on half mode substrate integrated waveguide," Microwave & Optical Technology Letters, Vol. 60, 2018.
4. Naeem, U., M. B. Khan, and M. F. Shafique, "Design of compact dual-mode dual-band SIW filter with independent tuning capability," Microwave and Optical Technology Letters, Vol. 60, No. 1, 178-182, 2018.
doi:10.1002/mop.30934
5. Amari, S., U. Rosenberg, and J. Bornemann, "Adaptive synthesis and design of resonator filters with source/load-multiresonator coupling," IEEE Transactions on Microwave Theory and Techniques, Vol. 50, No. 8, 1969-1978, 2002.
doi:10.1109/TMTT.2002.801348
6. Lu, D., T. F. Yan, and X. H. Tang, "Compact quasi-elliptic combline filter in single-layered SIW technology with two tunable transmission zeros," IEEE Wireless & Microwave Technology Conference, 2016.
7. Sigmarsson, H. H., et al., "Reconfigurable-order bandpass filter for frequency agile systems," Microwave Symposium Digest, IEEE, 2010.
8., "Compact frequency and bandwidth tunable bandpass-bandstop microstrip filter," IEEE Microwave and Wireless Components Letters, 1-3, 2018.
9. You, B., L. Chen, and G. Luo, "The novel reconfigurable double-layer half-mode SIW filter with tunable DMS structure," Journal of Electromagnetic Waves and Applications, 1-8, 2018.
10. Zhu, Y. Z., "A compact double folded quarter mode substrate integrated waveguide (DFQMSIW) filter," IEICE Electronics Express, Vol. 13, No. 11, 20160330-20160330, 2016.
doi:10.1587/elex.13.20160330
11. Chi, P. L, T. Yang, and T. Y. Tsai, "A fully tunable two-pole bandpass filter," IEEE Microwave and Wireless Components Letters, Vol. 25, No. 5, 292-294, 2015.
doi:10.1109/LMWC.2015.2409794