A Ka band broadband bandpass substrate integrated waveguide filter

In this paper, a Ka band broadband bandpass filter with substrate integrated waveguide (SIW) technology is presented and investigated with simulation and experiment, which can provide 32.7% fractional bandwidth at the center frequency of 35GHz. In order to connect with microstrip circuits, an SIW to microstrip transition is included in this design. Simulation results, which are in agreement with measurement results, show that the filter has moderate return loss and insertion loss in working band.