A Bandpass Filter with Good Out-of-band Rejection Based on SIW Technology for 5G Communication

In this paper, a bandpass filter with good out-of-band rejection based on the substrate integrated waveguide(SIW) Technology is proposed. This SIW resonant cavity can effectively suppress the signal overflow, thus significantly improving the Q factor and achieving low loss. At the same time, in order to reduce out-of-band parasitic resonance, a loaded short cut-off line is designed at the feed line, thus introducing new transmission zeros in the high-frequency range. The position of each TZ can be controlled independently, resulting in the design of a high performance multimode bandpass filter (BPF).