Wideband substrate integrated waveguide Ku-band coupler

Abstract

This paper deals with a 3 dB Ku-band coupler designed in substrate integrated waveguide (SIW) technology. A microstrip-SIW-transition is designed with a return loss (RL) greater than 20 dB. Rogers 4003 substrate is used for the SIW with a gold plated copper metallisation. The coupler achieves a relative bandwidth of 26.1% with an insertion loss (IL) lower than 2 dB, coupling balance smaller than 0.5 dB and RL and isolation greater than 15 dB.