A Miniaturized Bandpass Filter Basing on HMSIW Loaded Dual-mode CSRR

In this paper, a miniaturized bandpass filter is proposed basing on half-mode substrate integrated waveguide (HMSIW) loaded dual-mode complementary split-ring resonator (CSRR). The HMSIW is a derivative of substrate integrated waveguide(SIW), and the dimension is 50% of the SIW, so it is more conducive to decrease the size of the filter. Meanwhile, the dual-mode CSRR is loaded on the HMSIW, which can further reduce the size of the filter. Besides, loading dual-mode CSRR can obtain a wider operating bandwidth and generate two transmission zeros in the upper sideband to enhance the frequency selectivity compare with loading traditional CSRR. To verify the validity, the miniaturized bandpass filter is designed and optimized in HFSS software. The simulation results show that the center frequency is 7.44 GHz, 3-dB fractional bandwidth is 16.9% from 6.84 to 8.10 GHz. The final size of the filter is 0.167 lambda gx0.463 lambda g, the miniaturization design of the filter is realized.