Design and analysis of C-band siw directional coupler

For C band receptor applications, an efficient and compact sized four port directional coupler has been designed using Substrate Integrated Waveguide technique. Dielectric filled waveguide (DFW) devices replace the microstrip devices as they are inefficient at high frequencies. With the help of via holes, DFW is converted to Substrate Integrated Waveguide (SIW) to considerably reduce the dielectric losses and the high cost of manufacturing involved in conventional waveguides. The proposed directional coupler can be implemented at satellite and radar reception applications. The miniaturized circuit offers planar integration with other circuits. The proposed circuit exhibits efficient insertion loss and return loss characteristics in the operating band that ranges from 5.5 GHz to 8 GHz with a central resonant frequency of 7 GHz.