Millimeter-wave substrate integrated waveguide filters

This paper presents the design and performance of millimeter waves filter realized with the SIW technology. Using the SIW, low-cost filter can be manufactured at millimeter-wave without tuning. A design methodology for Butterworth or Chebychev prototype is presented. Also a dual-mode filter is presented to improve the out of band rejection. An experimental inductive post Chebychev filter has been designed and measured. The 3 poles, 1 GHz bandwidth filter presents 1.1 dB insertion losses at 28 GHz and return loss better than 16.3 dB. Also, a dual mode filter has been designed and measured. The bandwidth of the 2-poles, 1-zero filter is 0.7 GHz. The insertion loss is 1.8 dB and return loss is better than 20 dB.