Compact substrate integrated waveguide directional couplers in Ku and K bands

Compact hybrids in substrate integrated waveguide (SIW) technology for Ku and K bands have been designed, simulated and built. The continuous coupling between adjacent waveguide concept has been used. Simulated and experimental results show good agreement. Bandwidth larger than 14% has been measured in Ku-band coupler with return loss higher than 21 dB and insertion loss ripple smaller than ±0.3 dB. A bandwidth of 22 % has been measured for the K-band coupler showing a return loss higher than 15 dB.