Design of E-band SIW Bandpass Filter Based on High Sub-mode

In this paper, an E-band substrate integrated waveguide (SIW) bandpass filter based on TE102 and TE201 modes is designed. The filter introduces one or more transmission zeros by introducing high secondary modes, which can couple with low frequency modes in the resonant cavity. Compared to moment conventional linear SIW filters, the filter's out-of-band rejection performance is improved, which is more conducive to the miniaturization of the component design. The filter has a passband range of 81-86 GHz.With an in-band insertion loss of less than 2.6 dB, an in-band return loss of more than 16 dB, an out-of-band rejection of less than 23 dB in the 70-78 GHz band, and a blocking-band rejection of 25 dB at 88-100 GHz.The filter proposed in this paper has the advantages of miniaturization, high integration and high selectivity.