A compact wideband quarter mode substrate integrated waveguide (QMSIW) band-pass filter with wide stopband performance is presented in this paper. Compared with conventional SIW cavity, the QMSIW cavity occupies only one fourth of the size. A meandered H-shaped slot is etched on the cavity to change the current direction for size reduction. In order to prove the validity, a compact fourth-order band-pass filter with wide stopband is fabricated on a single-layer Rogers RT/Duroid 5880 substrate. The measured in-band insertion loss is only 1.02 dB including the loss caused by two connectors, and the stopband attenuation in the frequency band from 4.02 GHz to 12.63 GHz is better than 25 dB. The whole size of the filter is only 20.6×26.8×0.254 mm3.
2. Xu, Z. Q., et al., "Substrate integrated waveguide filter with embedded mixed source-load coupling," Electronics Letters, Vol. 49, No. 23, 1464-1465, 2013.
3. Huang, L., et al., "Substrate integrated waveguide filters with broadside-coupled complementary split ring resonators," IET Microwaves Antennas & Propagation, Vol. 7, No. 10, 795-801, 2013.
4. Shen, W., W. Y. Yin, and X. W. Sun, "Miniaturized dual-band substrate integrated waveguide filter with controllable bandwidths," IEEE Microwave & Wireless Components Letters, Vol. 21, No. 8, 418-420, 2011.
5. Wang, K., et al., "Synthesis method for substrate-integrated waveguide bandpass filter with even-order chebyshev response," IEEE Transactions on Components Packaging & Manufacturing Technology, Vol. 6, No. 1, 126-135, 2016.
6. Chen, R. S., et al., "Wideband bandpass filter using U-slotted Substrate Integrated Waveguide (SIW) cavities," IEEE Microwave & Wireless Components Letters, Vol. 25, No. 1, 1-3, 2015.
7. Zhang, X., C. Ma, and F. Wang, "Design of compact dual-passband LTCC filter exploiting stacked QMSIW and EMSIW," Electronics Letters, Vol. 51, No. 12, 912-914, 2015.
8. Guo, Z., K. S. Chin, W. Che, and C.-C. Chang, "Cross-coupled band-pass filters using QMSIW cavities and S-shaped slot coupling structures," Journal of Electromagnetic Waves and Applications, Vol. 27, No. 2, 160-167, 2013.
9. Liu, C. N., C. H. Teng, and C. W. Tang, "Design of the wide stopband microstrip band-pass filter by cascading stepped coupled lines," IEEE Microwave Conference, 1148-1150, 2014.
10. Chen, X. P., K. Wu, and D. Drolet, "Substrate integrated waveguide filter with improved stopband performance for satellite ground terminal," IEEE Transactions on Microwave Theory & Techniques, Vol. 57, No. 3, 674-683, 2009.
11. Hong, J. S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, Wiley, New York, 2001.