A wide stopband filter based on substrate integrated waveguide (SIW) is proposed. Using a right-angle coupling structure, the filter has two transmission zeros (TZs) in the upper stopband. These TZs are located near the resonant frequencies of the two different second-order modes (TE102/TE201), respectively. To further improve the stopband performance, two rectangular slots are etched on the top metal layer of the SIW. The insertion loss is approximately 1.9 dB at the center frequency of 10 GHz. The return loss in the passband is more than 20 dB. The stopband attenuation within 10.518.8 GHz is better than 20 dB, and the second harmonic response is effectively inhibited. Compared with the traditional bandpass filter based on SIW, the stopband bandwidth of this filter is widened by 48%. Measured results well agree with numerical simulations.
REN Long1,2, MENG Ling-qin1,2, ZHU Jun-hao1, ZHOU Jing-chao1, LIU Jie1
. Wide Stopband SIW Filter with Right-Angle Coupling Structure[J]. Journal of Shanghai University, 2014
, 20(4)
: 466
-471
.
DOI: 10.3969/j.issn.1007-2861.2013.07.033
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