Integrated Substrate Gap Waveguide Electromagnetic Coupled Filter with High Selectivity

This paper proposes an electromagnetic coupled bandpass filter based on integrated substrate gap waveguide (ISGW). The 3dB passband range of the proposed filter is 30.8-33.74GHz with the center frequency of 32.27GHz, which is suitable for 5G millimeter wave systems. The stopband bandwidth with an out-of-band rejection level better than 20dB reaches nearly 10GHz. Two transmission zeros (TZ) are generated at frequencies of 29.85GHz and 35.1GHz, respectively, enhancing the out-of-band rejection and improving the frequency selectivity of the filter.