An SIW-Based Wideband 5G mmWave Bandpass Filter by Using Multimode Resonator

In this letter, a wideband bandpass filter (BPF) is proposed for the first time by embedding a multimode resonator (MMR) in one substrate integrated waveguide (SIW) cavity. This design has a wide bandwidth by combining the fundamental mode of SIW (i.e., TE110 mode) and the separated odd/even modes of MMR. A filter covering 22.24–31.74 GHz is obtained to behave low insertion loss, high selectivity, wide operating bandwidth, and high out-of-band suppression. The measured results show that this filter could provide a promising candidate for the fifth-generation (5G) millimeter-wave (mmWave) communication systems.