Millimeter Wave (mmw) Substrate Integrated Waveguide Filter

Filter is a key device for wireless communication systems and radar systems. Filter is so essential to the high-performance microwave and millimeter wave circuit (such as Oscillator, Frequency multiplier, Mixers). With the rapid development of satellite communications and wireless communications, the high performance of filter in the microwave and millimeter wave system have become increasingly demanding, Such as high frequency selective, broadband and miniaturization.At first, this paper designs a traditional Ka-bands E-plane fins line filter, and discussed increase the bandwidth by broaden the wide edge of the rectangular waveguide. And then, explore the multilayer filter based on the substrate integrated waveguide(SIW). Finally, this article designs a SIW filter with loading two Defected ground structure(DGS) Split-Ring Resonator(SRR). The filter uses the cross-coupling resonator with source-load coupling, realize three cavity cross coupling with source-load coupling in a single SIW cavity, make the filter structure more compact, and there are three transmission zeros in the stop-band.According to the test, the filter center frequency is26.6GHz,3dB bandwidth is7.17dB, the insertion loss of center frequency is1.23dB, the return loss of pass-band is more than12.13dB. There are three transmission zeros, respectively in20GHz,21.46GHz and38.05GHz. The measured results and simulation results are similar.