CPW-to-waveguide transition using three-step Chebyshev transformer

A transition structure between a coplanar line and a rectangular waveguide using a three-step Chebyshev transformer is proposed. The structure was designed, manufactured and tested in the X-band. Measurement results show good agreement with the simulation results. A bandwidth of 32% with a return loss better than -20 dB and an insertion loss better than -1 dB over the X-band were obtained.